10 CFR 50.75 - Reporting and recordkeeping for decommissioning planning.

Code of Federal Regulations, 2010 CFR

2010-01-01

... investing or otherwise, that a prudent investor would use in the same circumstances. The term “prudent... than or equal to 3400 MWt $105 between 1200 MWt and 3400 MWt (For a PWR of less than 1200 MWt, use P... 3400 MWt (For a BWR of less than 1200 MWt, use P=1200 MWt) $(104+0.009P) (2) An adjustment factor at...

A summary of the results from the DOE advanced gas reactor (AGR) fuel development and qualification program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Petti, David Andrew

2017-04-01

Modular high temperature gas-cooled reactor (HTGR) designs were developed to provide natural safety, which prevents core damage under all licensing basis events. The principle that guides their design concepts is to passively maintain core temperatures below fission product release thresholds under all accident scenarios. The required level of fuel performance and fission product retention reduces the radioactive source term by many orders of magnitude relative to source terms for other reactor types and allows a graded approach to emergency planning and the potential elimination of the need for evacuation and sheltering beyond a small exclusion area. Achieving this level, however,more » is predicated on exceptionally high coated-particle fuel fabrication quality and excellent performance under normal operation and accident conditions. The design goal of modular HTGRs is to meet the Environmental Protection Agency (EPA) Protective Action Guides (PAGs) for offsite dose at the Exclusion Area Boundary (EAB). To achieve this, the reactor design concepts require a level of fuel integrity that is far better than that achieved for all prior U.S.-manufactured tristructural isotropic (TRISO) coated particle fuel.« less

[Individualization of exercise load control for inpatient cardiac rehabilitation. Development and evaluation of a HRV-based intervention program for patients with ischemic heart failure].

PubMed

Behrens, K; Hottenrott, K; Weippert, M; Montanus, H; Kreuzfeld, S; Rieger, A; Lübke, J; Werdan, K; Stoll, R

2015-03-01

The effective use of rehabilitation programs is of primary importance in order to improve the physical performance of cardiac disease patients. A modular program has been developed which is intended to structure and individualize conventional, exercise-based rehabilitation programs according to the individual needs and physical condition of each patient. The individualization of the program is based on detailed diagnostics before patients enter the program and daily measurements of heart rate variability (HRV) during cardiac rehabilitation. A total of 30 patients with ischemic heart disease were randomly assigned either to the intervention group (IG), completing the modular individualized rehabilitation program [n=15, mean age 54.4±4.2 years and mean left ventricular ejection fraction (LVEF) 28.53±6.25%) or to the control group (CG) taking part in the conventional rehabilitation program (n=15, mean age 56.4±4.4 years and mean LVEF 27.63±5.62). Before and after the intervention, cardiorespiratory fitness was assessed by measurement of maximal oxygen consumption (relative VO2max) during bicycle ergometry and the 6-minute walk test (6-MWT). Pre-post comparisons of cardiorespiratory fitness indicators were used to evaluate the effectiveness of the rehabilitation program. In addition to the results of the basic clinical investigations and the cardiorespiratory testing, results of standardized HRV measurements of 10 min at morning rest served as criteria for program individualization. The relative VO2max increased significantly (p<0.05) in the IG whereas no change was found in the CG. Similar results were found for maximum power output during bicycle ergometry (p<0.01) and for 6-MWT distance (p<0.001). Although patients in the IG completed less aerobic exercise sessions than those in the CG (p<0.001) the physical performance of the IG improved significantly. The results prove the effectiveness and efficacy of the modular individualized rehabilitation program. They further suggest the need for an individual program matrix instead of a maximum performance matrix in cardiac rehabilitation. Individualization should be based on clinical and performance diagnostics before and accompanying assessments of training condition, e.g. by HRV measurements, during rehabilitation programs. Each patient should only perform those intervention programs which match the results of the basic clinical investigation and additional analyses during rehabilitation.

Comparison of two- and six-minute walk tests in detecting oxygen desaturation in patients with severe chronic obstructive pulmonary disease — A randomized crossover trial

PubMed Central

Teschler, Sebastian; Jarosch, Inga; Christle, Jeffrey W; Hitzl, Wolfgang; Kenn, Klaus

2016-01-01

The two-minute walk test (2MWT) is less well validated than the well-known six-minute walk test (6MWT) as a field walking test in patients with chronic obstructive pulmonary disease (COPD). The primary objective of this study was to compare the accuracy of the 2MWT to the 6MWT in detecting exercise-induced oxygen desaturation in patients with severe COPD. Twenty-six patients with COPD (age: 61 ± 10 years, forced expired volume in one second: 37 ± 10%) that were normoxemic at rest performed a 2MWT and a 6MWT under normal ambient conditions on two consecutive days in random order. Oxygen saturation, total walking distance, heart rate, breathing frequency, dyspnea, and leg fatigue were evaluated. Average walking distances were 150 m (95% confidence interval (95% CI): 134–165 m) and 397 m (95% CI: 347–447 m) for the 2MWT and 6MWT, respectively (r = 0.80, p < 0.0001). The difference in minimum oxygen saturation during the 2MWT (83%, 95% CI: 81–86%) and 6MWT (mean 82%, 95% CI: 80–84%) was not statistically different and the data strongly correlated between the groups (r = 0.81, p < 0.0001). Other measurements from the 6MWT, including heart rate, breathing rate, and levels of perceived exertion were also comparable in 2MWT. The 2MWT showed comparable validity in detecting exercise-induced oxygen desaturation in patients with severe COPD compared to the 6MWT. PMID:26961775

Comparison of two- and six-minute walk tests in detecting oxygen desaturation in patients with severe chronic obstructive pulmonary disease - A randomized crossover trial.

PubMed

Gloeckl, Rainer; Teschler, Sebastian; Jarosch, Inga; Christle, Jeffrey W; Hitzl, Wolfgang; Kenn, Klaus

2016-03-08

The two-minute walk test (2MWT) is less well validated than the well-known six-minute walk test (6MWT) as a field walking test in patients with chronic obstructive pulmonary disease (COPD). The primary objective of this study was to compare the accuracy of the 2MWT to the 6MWT in detecting exercise-induced oxygen desaturation in patients with severe COPD. Twenty-six patients with COPD (age: 61 ± 10 years, forced expired volume in one second: 37 ± 10%) that were normoxemic at rest performed a 2MWT and a 6MWT under normal ambient conditions on two consecutive days in random order. Oxygen saturation, total walking distance, heart rate, breathing frequency, dyspnea, and leg fatigue were evaluated. Average walking distances were 150 m (95% confidence interval (95% CI): 134-165 m) and 397 m (95% CI: 347-447 m) for the 2MWT and 6MWT, respectively (r = 0.80, p < 0.0001). The difference in minimum oxygen saturation during the 2MWT (83%, 95% CI: 81-86%) and 6MWT (mean 82%, 95% CI: 80-84%) was not statistically different and the data strongly correlated between the groups (r = 0.81, p < 0.0001). Other measurements from the 6MWT, including heart rate, breathing rate, and levels of perceived exertion were also comparable in 2MWT. The 2MWT showed comparable validity in detecting exercise-induced oxygen desaturation in patients with severe COPD compared to the 6MWT. © The Author(s) 2016.

User's manual for the Composite HTGR Analysis Program (CHAP-1)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gilbert, J.S.; Secker, P.A. Jr.; Vigil, J.C.

1977-03-01

CHAP-1 is the first release version of an HTGR overall plant simulation program with both steady-state and transient solution capabilities. It consists of a model-independent systems analysis program and a collection of linked modules, each representing one or more components of the HTGR plant. Detailed instructions on the operation of the code and detailed descriptions of the HTGR model are provided. Information is also provided to allow the user to easily incorporate additional component modules, to modify or replace existing modules, or to incorporate a completely new simulation model into the CHAP systems analysis framework.

A Review of Microwave Thermography Nondestructive Testing and Evaluation

PubMed Central

Zhang, Hong; Yang, Ruizhen; He, Yunze; Foudazi, Ali; Cheng, Liang; Tian, Guiyun

2017-01-01

Microwave thermography (MWT) has many advantages including strong penetrability, selective heating, volumetric heating, significant energy savings, uniform heating, and good thermal efficiency. MWT has received growing interest due to its potential to overcome some of the limitations of microwave nondestructive testing (NDT) and thermal NDT. Moreover, during the last few decades MWT has attracted growing interest in materials assessment. In this paper, a comprehensive review of MWT techniques for materials evaluation is conducted based on a detailed literature survey. First, the basic principles of MWT are described. Different types of MWT, including microwave pulsed thermography, microwave step thermography, microwave pulsed phase thermography, and microwave lock-in thermography are defined and introduced. Then, MWT case studies are discussed. Next, comparisons with other thermography and NDT methods are conducted. Finally, the trends in MWT research are outlined, including new theoretical studies, simulations and modelling, signal processing algorithms, internal properties characterization, automatic separation and inspection systems. This work provides a summary of MWT, which can be utilized for material failures prevention and quality control. PMID:28505130

Within-day variability on short and long walking tests in persons with multiple sclerosis.

PubMed

Feys, Peter; Bibby, Bo; Romberg, Anders; Santoyo, Carme; Gebara, Benoit; de Noordhout, Benoit Maertens; Knuts, Kathy; Bethoux, Francois; Skjerbæk, Anders; Jensen, Ellen; Baert, Ilse; Vaney, Claude; de Groot, Vincent; Dalgas, Ulrik

2014-03-15

To compare within-day variability of short (10 m walking test at usual and fastest speed; 10MWT) and long (2 and 6-minute walking test; 2MWT/6MWT) tests in persons with multiple sclerosis. Observational study. MS rehabilitation and research centers in Europe and US within RIMS (European network for best practice and research in MS rehabilitation). Ambulatory persons with MS (Expanded Disability Status Scale 0-6.5). Subjects of different centers performed walking tests at 3 time points during a single day. 10MWT, 2MWT and 6MWT at fastest speed and 10MWT at usual speed. Ninety-five percent limits of agreement were computed using a random effects model with individual pwMS as random effect. Following this model, retest scores are with 95% certainty within these limits of baseline scores. In 102 subjects, within-day variability was constant in absolute units for the 10MWT, 2MWT and 6MWT at fastest speed (+/-0.26, 0.16 and 0.15m/s respectively, corresponding to +/-19.2m and +/-54 m for the 2MWT and 6MWT) independent on the severity of ambulatory dysfunction. This implies a greater relative variability with increasing disability level, often above 20% depending on the applied test. The relative within-day variability of the 10MWT at usual speed was +/-31% independent of ambulatory function. Absolute values of within-day variability on walking tests at fastest speed were independent of disability level and greater with short compared to long walking tests. Relative within-day variability remained overall constant when measured at usual speed. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

Relationships between heart rate target determined in different exercise testing in COPD patients to prescribed with individualized exercise training.

PubMed

Fabre, Claudine; Chehere, Baptiste; Bart, Frédéric; Mucci, Patrick; Wallaert, Benoit; Grosbois, Jean Marie

2017-01-01

It has been scientifically proven that pulmonary rehabilitation improves exercise tolerance and facilitates the carrying out of daily physical activities. To optimize the physical and physiological benefits, it is necessary to individualize the training intensity for each patient. The aim of this study is to compare the heart rate (HR) responses to three exercise modalities measuring aerobic fitness in chronic obstructive pulmonary disease patients, in order to easily prescribe individual target HRs for endurance training. Fifty COPD patients (mean age: 60.1±8.5 years) were included in the study. Each patient carried out a cardiopulmonary exercise test, a 6-minute walk test (6MWT) and a 6-minute stepper test (6MST). During these tests, HR was recorded continuously. After the cardiopulmonary exercise test, the HR was noted at the ventilatory threshold (VT) and at the end of the two exercise field tests (6MWT peak and 6MST peak ). The values of the HR during the last 3 minutes of both field tests were averaged (6MWT 456 and 6MST 456 ). Finally, the HR at 60% of the HR reserve was calculated with the values of the HR measured during 6MWT and 6MST (HRr 60%walk , HRr 60%step ). The HRs measured during the 6MST were significantly higher than those measured during the 6MWT. The HRr 60%step was not significantly different from 6MWT 456 and 6MWT peak HR ( P =0.51; P =0.48). A significant correlation was observed between 6MWT 456 and 6MWT peak ( r =0.58). The 6MWT 456 and 6MWT peak HR were correlated with HRr 60%step ( r =0.68 and r =0.62). The VT could be determined in 28 patients. The HR VT was not different from 6MWT 456 , 6MWT peak , and HRr 60%step ( P =0.57, P =0.41 and P =0.88) and was correlated to 6MWT 456 , 6MWT peak , and HRr 60%step ( r =0.45, r =0.40, r =0.48). An individualized target HR for endurance training can be prescribed from the HR measured during routine tests, such as 6MWT or 6MST.

The IAEA coordinated research programme on HTGR uncertainty analysis: Phase I status and Ex. I-1 prismatic reference results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bostelmann, Friederike; Strydom, Gerhard; Reitsma, Frederik

The quantification of uncertainties in design and safety analysis of reactors is today not only broadly accepted, but in many cases became the preferred way to replace traditional conservative analysis for safety and licensing analysis. The use of a more fundamental methodology is also consistent with the reliable high fidelity physics models and robust, efficient, and accurate codes available today. To facilitate uncertainty analysis applications a comprehensive approach and methodology must be developed and applied, in contrast to the historical approach where sensitivity analysis were performed and uncertainties then determined by a simplified statistical combination of a few important inputmore » parameters. New methodologies are currently under development in the OECD/NEA Light Water Reactor (LWR) Uncertainty Analysis in Best-Estimate Modelling (UAM) benchmark activity. High Temperature Gas-cooled Reactor (HTGR) designs require specific treatment of the double heterogeneous fuel design and large graphite quantities at high temperatures. The IAEA has therefore launched a Coordinated Research Project (CRP) on HTGR Uncertainty Analysis in Modelling (UAM) in 2013 to study uncertainty propagation specifically in the HTGR analysis chain. Two benchmark problems are defined, with the prismatic design represented by the General Atomics (GA) MHTGR-350 and a 250 MW modular pebble bed design similar to the Chinese HTR-PM. Work has started on the first phase and the current CRP status is reported in the paper. A comparison of the Serpent and SCALE/KENO-VI reference Monte Carlo results for Ex. I-1 of the MHTGR-350 design is also included. It was observed that the SCALE/KENO-VI Continuous Energy (CE) k ∞ values were 395 pcm (Ex. I-1a) to 803 pcm (Ex. I-1b) higher than the respective Serpent lattice calculations, and that within the set of the SCALE results, the KENO-VI 238 Multi-Group (MG) k ∞ values were up to 800 pcm lower than the KENO-VI CE values. The use of the latest ENDF-B-VII.1 cross section library in Serpent lead to ~180 pcm lower k ∞ values compared to the older ENDF-B-VII.0 dataset, caused by the modified graphite neutron capture cross section. Furthermore, the fourth beta release of SCALE 6.2 likewise produced lower CE k∞ values when compared to SCALE 6.1, and the improved performance of the new 252-group library available in SCALE 6.2 is especially noteworthy. A SCALE/TSUNAMI uncertainty analysis of the Hot Full Power variant for Ex. I-1a furthermore concluded that the 238U(n,γ) (capture) and 235U(View the MathML source) cross-section covariance matrices contributed the most to the total k ∞ uncertainty of 0.58%.« less

The IAEA coordinated research programme on HTGR uncertainty analysis: Phase I status and Ex. I-1 prismatic reference results

DOE PAGES

Bostelmann, Friederike; Strydom, Gerhard; Reitsma, Frederik; ...

2016-01-11

The quantification of uncertainties in design and safety analysis of reactors is today not only broadly accepted, but in many cases became the preferred way to replace traditional conservative analysis for safety and licensing analysis. The use of a more fundamental methodology is also consistent with the reliable high fidelity physics models and robust, efficient, and accurate codes available today. To facilitate uncertainty analysis applications a comprehensive approach and methodology must be developed and applied, in contrast to the historical approach where sensitivity analysis were performed and uncertainties then determined by a simplified statistical combination of a few important inputmore » parameters. New methodologies are currently under development in the OECD/NEA Light Water Reactor (LWR) Uncertainty Analysis in Best-Estimate Modelling (UAM) benchmark activity. High Temperature Gas-cooled Reactor (HTGR) designs require specific treatment of the double heterogeneous fuel design and large graphite quantities at high temperatures. The IAEA has therefore launched a Coordinated Research Project (CRP) on HTGR Uncertainty Analysis in Modelling (UAM) in 2013 to study uncertainty propagation specifically in the HTGR analysis chain. Two benchmark problems are defined, with the prismatic design represented by the General Atomics (GA) MHTGR-350 and a 250 MW modular pebble bed design similar to the Chinese HTR-PM. Work has started on the first phase and the current CRP status is reported in the paper. A comparison of the Serpent and SCALE/KENO-VI reference Monte Carlo results for Ex. I-1 of the MHTGR-350 design is also included. It was observed that the SCALE/KENO-VI Continuous Energy (CE) k ∞ values were 395 pcm (Ex. I-1a) to 803 pcm (Ex. I-1b) higher than the respective Serpent lattice calculations, and that within the set of the SCALE results, the KENO-VI 238 Multi-Group (MG) k ∞ values were up to 800 pcm lower than the KENO-VI CE values. The use of the latest ENDF-B-VII.1 cross section library in Serpent lead to ~180 pcm lower k ∞ values compared to the older ENDF-B-VII.0 dataset, caused by the modified graphite neutron capture cross section. Furthermore, the fourth beta release of SCALE 6.2 likewise produced lower CE k∞ values when compared to SCALE 6.1, and the improved performance of the new 252-group library available in SCALE 6.2 is especially noteworthy. A SCALE/TSUNAMI uncertainty analysis of the Hot Full Power variant for Ex. I-1a furthermore concluded that the 238U(n,γ) (capture) and 235U(View the MathML source) cross-section covariance matrices contributed the most to the total k ∞ uncertainty of 0.58%.« less

NRC Licensing Status Summary Report for NGNP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moe, Wayne Leland; Kinsey, James Carl

2014-11-01

The Next Generation Nuclear Plant (NGNP) Project, initiated at Idaho National Laboratory (INL) by the U.S. Department of Energy (DOE) pursuant to provisions of the Energy Policy Act of 2005, is based on research and development activities supported by the Department of Energy Generation IV Nuclear Energy Systems Initiative. The principal objective of the NGNP Project is to support commercialization of high temperature gas-cooled reactor (HTGR) technology. The HTGR is a helium-cooled and graphite moderated reactor that can operate at temperatures much higher than those of conventional light water reactor (LWR) technologies. The NGNP will be licensed for construction andmore » operation by the Nuclear Regulatory Commission (NRC). However, not all elements of current regulations (and their related implementation guidance) can be applied to HTGR technology at this time. Certain policies established during past LWR licensing actions must be realigned to properly accommodate advanced HTGR technology. A strategy for licensing HTGR technology was developed and executed through the cooperative effort of DOE and the NRC through the NGNP Project. The purpose of this report is to provide a snapshot of the current status of the still evolving pre-license application regulatory framework relative to commercial HTGR technology deployment in the U.S. The following discussion focuses on (1) describing what has been accomplished by the NGNP Project up to the time of this report, and (2) providing observations and recommendations concerning actions that remain to be accomplished to enable the safe and timely licensing of a commercial HTGR facility in the U.S.« less

Multi-Megawatt Space Nuclear Power Generation

DTIC Science & Technology

1993-06-28

electric generation, both for open- and closed-cycle opera- tion. These reactors use the particulate fuel of the type developed for HTGR reactors. What...commercial HTGR power reactors, the particles are held in place and directly cooled. Figure 2.7 shows the two types of fuel particles developed for...of MW(e), for pulsed energy devices. The FBR would use HTGR -type particle fuel , contained in a annular bed be- tween two porous frits. Helium would

JPRS Report, Science & Technology, China: Energy

DTIC Science & Technology

1988-06-29

capacity. There are currently two types of HTGR reactor designs: the particle-bed core , which uses spherical fuel elements, and the rod type core , in...and trial operating experience with the HTGR reactor. Its main design features are as follows. 1. A particle-bed core , continuous fueling and...Favorable for Development of Small-Scale HTGR (Xu Jiming; HE DONGLI GONGCHENG, Feb 88) 47 ERRATUM: In JPRS-CEN-88-003 of 25 April 1988 in article

Using SA508/533 for the HTGR Vessel Material

DOE Office of Scientific and Technical Information (OSTI.GOV)

Larry Demick

2012-06-01

This paper examines the influence of High Temperature Gas-cooled Reactor (HTGR) module power rating and normal operating temperatures on the use of SA508/533 material for the HTGR vessel system with emphasis on the calculated times at elevated temperatures approaching or exceeding ASME Code Service Limits (Levels B&C) to which the reactor pressure vessel could be exposed during postulated pressurized and depressurized conduction cooldown events over its design lifetime.

The Maintenance of Wakefulness Test and driving simulator performance.

PubMed

Banks, Siobhan; Catcheside, Peter; Lack, Leon C; Grunstein, Ron R; McEvoy, R Doug

2005-11-01

It has been suggested that the Maintenance of Wakefulness Test (MWT) may be clinically useful to assess fitness to drive, yet little is known about the actual relationship between sleep latency and driving performance. This study examined the ability of 2 MWT trials to predict driving-simulator performance in healthy individuals. Experimental. NA. Twenty healthy volunteers (mean age 22.8 years; 9 men). NA. The MWT and driving-simulator performance were examined under 2 conditions-partial sleep deprivation and a combination of partial sleep deprivation and alcohol consumption. Each subject was studied a week apart, with the order randomly assigned. Subjects completed a nighttime 70-minute AusEd driving simulation task and two 40-minute MWT trials, 1 before (MWT1) and 1 after (MWT2) the driving task. In the sleep-deprived condition, the MWT1 sleep latency was inversely correlated with braking reaction time. During the partial sleep deprivation and alcohol condition, the number of microsleeps during the driving task, steering deviation, braking reaction time, and crashes all negatively correlated with the MWT1 sleep latency. Additionally, construction of a receiver-operator characteristic curve revealed that MWT1 sleep latency in the partial sleep deprivation plus alcohol condition significantly discriminated subjects who had a crash from those who did not. These results indicate that sleep latency on the MWT is a reasonable predictor of driving simulator performance in sleepy, alcohol-impaired, normal subjects. Further research is needed to examine the relationship between daytime MWT results and driving simulator performance in sleepy patients (eg, those with obstructive sleep apnea) and in experimentally sleep-deprived normal subjects.

Reliability and intensity of the six-minute walk test in healthy elderly subjects.

PubMed

Kervio, Gaelle; Carre, Francois; Ville, Nathalie S

2003-01-01

The 6-min walk test (6-MWT) is an easy and validated field test, generally used in patients to assess their physical capacity. We think that the 6-MWT could also be conducted in the same perspective in healthy subjects, aged 60-70 yr. However, little is known about the effect of the familiarization on the 6-MWT performance and the relative intensity of this test. The aims of this study were therefore to bring precision to the 6-MWT reliability and intensity in this population. METHODS; Over 3 d, 12 subjects performed two maximal exercise tests on treadmill and five 6-MWT (two in the morning and three in the afternoon) with a portable metabolic measurement system (Cosmed K4, Rome, Italy). The distance, walking speed, oxygen uptake (VO2 (max)), and heart rate (HR) values were measured during the 6-MWT. Distance, walking speed, and VO2(max) were only lower during the first two 6-MWT (respectively, P< 0.001, P< 0.001, and P< 0.05). HR was reliable from the first 6-MWT and was higher during the tests performed in the afternoon (P< 0.001). The intensity of the 6-MWT corresponded to 79.6 +/- 4.5% of the VO2(max), 85.8 +/- 2.5% of the HR (max), and 78.0 +/- 6.3% of the HR (reserve). Moreover, it was higher than the ventilatory threshold in each subject (P< 0.01). In healthy elderly subjects, the 6-MWT represents a submaximal exercise, but at almost 80% of the VO2(max). To be exploitable, two familiarization attempts are required to limit the learning effect. Finally, the 6-MWT time of day must be taken into account when assessing HR.

Modeling and Comparison of Options for the Disposal of Excess Weapons Plutonium in Russia

DTIC Science & Technology

2002-04-01

fuel LWR cooling time LWR Pu load rate LWR net destruction frac ~ LWR reactors op life mox core frac Excess Separated Pu HTGR Cycle Pu in Waste LWR MOX...reflecting the cycle used in this type of reactor. For the HTGR , the entire core consists of plutonium fuel , therefore a core fraction is not specified...cooling time Time spent fuel unloaded from HTGR reactor must cool before permanently stored 3 years Mox core fraction Fraction of

High-temperature gas-cooled reactor technology development program. Annual progress report for period ending December 31, 1982

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kasten, P.R.; Rittenhouse, P.L.; Bartine, D.E.

1983-06-01

During 1982 the High-Temperature Gas-Cooled Reactor (HTGR) Technology Program at Oak Ridge National Laboratory (ORNL) continued to develop experimental data required for the design and licensing of cogeneration HTGRs. The program involves fuels and materials development (including metals, graphite, ceramic, and concrete materials), HTGR chemistry studies, structural component development and testing, reactor physics and shielding studies, performance testing of the reactor core support structure, and HTGR application and evaluation studies.

Availability analysis of an HTGR fuel recycle facility. Summary report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharmahd, J.N.

1979-11-01

An availability analysis of reprocessing systems in a high-temperature gas-cooled reactor (HTGR) fuel recycle facility was completed. This report summarizes work done to date to define and determine reprocessing system availability for a previously planned HTGR recycle reference facility (HRRF). Schedules and procedures for further work during reprocessing development and for HRRF design and construction are proposed in this report. Probable failure rates, transfer times, and repair times are estimated for major system components. Unscheduled down times are summarized.

Relationship between lower limb muscle strength and 6-minute walk test performance in stroke patients.

PubMed

Pradon, Didier; Roche, Nicolas; Enette, Lievyn; Zory, Raphaël

2013-01-01

The aim of this study was to determine if lower limb muscle strength and/or spasticity are related to performance in the 6-min walk test (6MWT) in stroke patients. A total of 24 patients (12 males and 12 females) participated in the study. Muscle strength (Medical Research Council (MRC) scale) and spasticity (modified Ashworth scale) were assessed prior to the 6MWT. Heart rate was recorded at rest and during the 6MWT. Subjects were divided into two groups: (i) those with a high MRC sum score, and (ii) those with a low MRC sum score. The relationship between the 6MWT distance and the other parameters was analysed using a Spearman's rank correlation coefficient. There was a significant and positive relationship between 6MWT distance and lower limb muscle strength (p = 0.001), whereas no significant correlations were found between the 6MWT distance and spasticity, resting heart rate and heart rate during the 6MWT. The 6MWT distance may be a good indicator of lower limb muscle strength, and lower limb strengthening may improve gait capacity in stroke patients.

Artificial gait in complete spinal cord injured subjects: how to assess clinical performance.

PubMed

Pithon, Karla Rocha; Abreu, Daniela Cristina Carvalho de; Vasconcelos-Neto, Renata; Martins, Luiz Eduardo Barreto; Cliquet, Alberto

2015-02-01

Adapt the 6 minutes walking test (6MWT) to artificial gait in complete spinal cord injured (SCI) patients aided by neuromuscular electrical stimulation. Nine male individuals with paraplegia (AIS A) participated in this study. Lesion levels varied between T4 and T12 and time post injured from 4 to 13 years. Patients performed 6MWT 1 and 6MWT 2. They used neuromuscular electrical stimulation, and were aided by a walker. The differences between two 6MWT were assessed by using a paired t test. Multiple r-squared was also calculated. The 6MWT 1 and 6MWT 2 were not statistically different for heart rate, distance, mean speed and blood pressure. Multiple r-squared (r2 = 0.96) explained 96% of the variation in the distance walked. The use of 6MWT in artificial gait towards assessing exercise walking capacity is reproducible and easy to apply. It can be used to assess SCI artificial gait clinical performance.

Proceedings of the International Congress (12th), Corrosion Control for Low-Cost Reliability, Held in Houston, Texas on September 19 -24, 1993. Volume 1. Coatings

DTIC Science & Technology

1993-09-24

3]) Gas-cooled reactors were first developed in Europe and have been built since 1956. HTGR , equipped with the core of ceramic coated particle fuels ...demands must also be covered by nuclear energy in not so long future. Programs on developing the process heating HTGR have been promoted mainly in Germany...Material programs for HTGR have been promoted in several countries since late 1960’s which include the tasks of developing and qualifying materials, eg

Progress report on the k{sub infinity} measurements of HTGR type lattices with the oscillation technique at zero reactivity; Rapport d'advancement sur les mesures de K {sub infinite} des reseaux du type HTGR avec la technique de l'oscillateur a'reactivite' nulle (in French)

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1971-01-15

The principles of measuring k {sub infinity} for a HTGR lattice using the oscillation technique with zero reactivity were already presented at the ''9th reactor physics meeting of countries participating in the Dragon project''. A brief summary of the essential characteristics of the experiment is followed by a status report on present work.

Six-minute walking test in children with ESRD: discrimination validity and construct validity.

PubMed

Takken, Tim; Engelbert, Raoul; van Bergen, Monique; Groothoff, Jaap; Nauta, Jeroen; van Hoeck, Koen; Lilien, Marc; Helders, Paul

2009-11-01

The six-minute walking test (6MWT) may be a practical test for the evaluation functional exercise capacity in children with end-stage renal disease (ESRD). The aim of this study was to investigate the 6MWT performance in children with ESRD compared to reference values obtained in healthy children and, secondly, to study the relationship between 6MWT performance with anthropometric variables, clinical parameters, aerobic capacity and muscle strength. Twenty patients (13 boys and seven girls; mean age 14.1 +/- 3.4 years) on dialysis participated in this study. Anthropometrics were taken in a standardized manner. The 6MWT was performed in a 20-m-long track in a straight hallway. Aerobic fitness was measured using a cycle ergometer test to determine peak oxygen uptake (V O(2peak)), peak rate (W(peak)) and ventilatory threshold (VT). Muscle strength was measured using hand-held myometry. Children with ESRD showed a reduced 6MWT performance (83% of predicted, p < 0.0001), irrespective of the reference values used. The strongest predictors of 6MWT performance were haematocrit and height. Regression models explained 59% (haematocrit and height) to 60% (haematocrit) of the variance in 6MWT performance. 6MWT performance was not associated with V O(2peak), strength, or other anthropometric variables, but it was significantly associated with haematocrit and height. Children with ESRD scored lower on the 6MWT than healthy children. Based on these results, the 6MWT may be a useful instrument for monitoring clinical status in children with ESRD, however it cannot substitute for other fitness tests, such as a progressive exercise test to measure V O(2peak) or muscle strength tests.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baek, M. H.; Kim, S. J.; Yoo, J.

The major roles of a prototype SFR are to provide irradiation test capability for the fuel and structure materials, and to obtain operational experiences of systems. Due to a compromise between the irradiation capability and construction costs, the power level should be properly determined. In this paper, a trade-off study on the power level of the prototype SFR was performed from a neutronics viewpoint. To select candidate cores, the parametric study of pin diameters was estimated using 20 wt.% uranium fuel. The candidate cores of different power levels, 125 MWt, 250 MWt, 400 MWt, and 500 MWt, were compared withmore » the 1500 MWt reference core. The resulting core performance and economic efficiency indices became insensitive to the power at about 400-500 MWt and sharply deteriorated at about 125-250 MWt with decreasing core sizes. Fuel management scheme, TRU core performance comparing with uranium core, and sodium void reactivity were also evaluated with increasing power levels. It is found that increasing the number of batches showed higher burnup performance and economic efficiency. However, increasing the cycle length showed the trends in lower economic efficiency. Irradiation performance of TRU and enriched TRU cores was improved about 20 % and 50 %, respectively. The maximum sodium void reactivity of 5.2$ was confirmed less than the design limit of 7.5$. As a result, the power capacity of the prototype SFR should not be less than 250 MWt and would be appropriate at {approx} 500 MWt considering the performance and economic efficiency. (authors)« less

Design of a miniature wind turbine for powering wireless sensors

NASA Astrophysics Data System (ADS)

Xu, F. J.; Yuan, F. G.; Hu, J. Z.; Qiu, Y. P.

2010-04-01

In this paper, a miniature wind turbine (MWT) system composed of commercially available off-the-shelf components was designed and tested for harvesting energy from ambient airflow to power wireless sensors. To make MWT operate at very low air flow rates, a 7.6 cm thorgren plastic Propeller blade was adopted as the wind turbine blade. A sub watt brushless DC motor was used as generator. To predict the performance of the MWT, an equivalent circuit model was employed for analyzing the output power and the net efficiency of the MWT system. In theory, the maximum net efficiency 14.8% of the MWT system was predicted. Experimental output power of the MWT versus resistive loads ranging from 5 ohms to 500 ohms under wind speeds from 3 m/s to 4.5 m/s correlates well with those from the predicted model, which means that the equivalent circuit model provides a guideline for optimizing the performance of the MWT and can be used for fulfilling the design requirements by selecting specific components for powering wireless sensors.

Neutron dose rate analysis on HTGR-10 reactor using Monte Carlo code

NASA Astrophysics Data System (ADS)

Suwoto; Adrial, H.; Hamzah, A.; Zuhair; Bakhri, S.; Sunaryo, G. R.

2018-02-01

The HTGR-10 reactor is cylinder-shaped core fuelled with kernel TRISO coated fuel particles in the spherical pebble with helium cooling system. The outlet helium gas coolant temperature outputted from the reactor core is designed to 700 °C. One advantage HTGR type reactor is capable of co-generation, as an addition to generating electricity, the reactor was designed to produce heat at high temperature can be used for other processes. The spherical fuel pebble contains 8335 TRISO UO2 kernel coated particles with enrichment of 10% and 17% are dispersed in a graphite matrix. The main purpose of this study was to analysis the distribution of neutron dose rates generated from HTGR-10 reactors. The calculation and analysis result of neutron dose rate in the HTGR-10 reactor core was performed using Monte Carlo MCNP5v1.6 code. The problems of double heterogeneity in kernel fuel coated particles TRISO and spherical fuel pebble in the HTGR-10 core are modelled well with MCNP5v1.6 code. The neutron flux to dose conversion factors taken from the International Commission on Radiological Protection (ICRP-74) was used to determine the dose rate that passes through the active core, reflectors, core barrel, reactor pressure vessel (RPV) and a biological shield. The calculated results of neutron dose rate with MCNP5v1.6 code using a conversion factor of ICRP-74 (2009) for radiation workers in the radial direction on the outside of the RPV (radial position = 220 cm from the center of the patio HTGR-10) provides the respective value of 9.22E-4 μSv/h and 9.58E-4 μSv/h for enrichment 10% and 17%, respectively. The calculated values of neutron dose rates are compliant with BAPETEN Chairman’s Regulation Number 4 Year 2013 on Radiation Protection and Safety in Nuclear Energy Utilization which sets the limit value for the average effective dose for radiation workers 20 mSv/year or 10μSv/h. Thus the protection and safety for radiation workers to be safe from the radiation source has been fulfilled. From the result analysis, it can be concluded that the model of calculation result of neutron dose rate for HTGR-10 core has met the required radiation safety standards.

Four hundred meters walking test in the evaluation of heart failure patients.

PubMed

Zdrenghea, D; Beudean, Maria; Pop, Dana; Zdrenghea, V

2010-01-01

The best evaluation of the severity and prognosis of heart failure patients is obtained by the maximal exercise stress testing, but for the very large number of HF patients and for evaluation of their daily effort capacity submaximal stress testing, mainly 6 minutes walking test are used. The limit of 6mWT is that during it the patients are not motivated to walk and also, the periphery, so important for heart failure patients, is not equally involved. To compare a new fixed walking test-400m walking test with 6MWT and maximal exercise testing. There were investigated 20 patients with dilated cardiomyopathy (DCM). The patients were included in the study after the relief of the congestive syndrome. Each patient was submitted in three consecutive days to a maximal symptom-limited exercise stress test on cycloergometer, a six minutes walking test, a 400 meters walking test. The last one consisted of walking on a corridor 40 meters long, at a speed chosen by the patient himself. The results were expressed in seconds representing the necessary time to cover the established 400 meters of distance. During cycloergometer exercise stress test the calculated mean peak VO2 was 15.2 +/- 1.4 mlO2/kg/min (4.32 METs). The mean distance walked during 6MWT was 350 +/- 34m and the mean time needed to walk 400m (400mWT) was 300 +/- 27 seconds. The correlation between peak VO2 and distance walked during 6MWT was -0.40, a similar but negative value (r = -0.42) being registered between peak VO2 and time registered during 400mWT. Only weak correlation was registered between LVEF and all the three tests. In turn the correlation between distance registered during 6MWT and time registered during 400mWT was excellent: r = -0.60. 400mWT is a useful tool for the evaluation of submaximal effort capacity of CHF patients. Its value to evaluate exercise capacity is similar with that of the 6 MWT, but 400mWT can assure a better evaluation of peripheral involvement.

Clinical correlation between the 6-min walk test andcardiopulmonary exercise testing in patients with pulmonary arterial hypertension.

PubMed

Acar, Serap; Savcı, Sema; Kardibak, Didem; Özcan Kahraman, Buse; Akdeniz, Bahri; Özpelit, Ebru; Sevinç, Can

2016-12-20

The aims of the present study were to assess the relationship between the distance walked during the 6-min walk test (6MWT) and exercise capacity as determined by cardiopulmonary exercise testing (CPET) in patients with pulmonary arterial hypertension (PAH) and to investigate the prognostic value of the 6MWT in comparison to clinical parameters of CPET and echocardiography findings. Thirty PAH patients participated in the study. Subject characteristics and New York Heart Association (NYHA) classifications were recorded. All subjects completed the 6MWT and CPET. Relationships among the variables were analyzed by the Pearson correlation test. Correlation coefficients between 6MWT distance and other variables were determined by linear regression analysis. Distance walked in the 6MWT was significantly correlated with the following exercise parameters: peak oxygen consumption, work load, and metabolic equivalents. Additionally, cardiac index was correlated with peak oxygen consumption and metabolic equivalents. We also showed that cardiac index and age were two significant determinants for exercise performance, accounting for 35.4% of the variance in the 6MWT. The 6MWT provides information that may be a better index for the patient's NYHA functional class determination than maximal exercise testing.

A study on nonlinear estimation of submaximal effort tolerance based on the generalized MET concept and the 6MWT in pulmonary rehabilitation

PubMed Central

Szczegielniak, Jan; Łuniewski, Jacek; Stanisławski, Rafał; Bogacz, Katarzyna; Krajczy, Marcin; Rydel, Marek

2018-01-01

Background The six-minute walk test (6MWT) is considered to be a simple and inexpensive tool for the assessment of functional tolerance of submaximal effort. The aim of this work was 1) to background the nonlinear nature of the energy expenditure process due to physical activity, 2) to compare the results/scores of the submaximal treadmill exercise test and those of 6MWT in pulmonary patients and 3) to develop nonlinear mathematical models relating the two. Methods The study group included patients with the COPD. All patients were subjected to a submaximal exercise test and a 6MWT. To develop an optimal mathematical solution and compare the results of the exercise test and the 6MWT, the least squares and genetic algorithms were employed to estimate parameters of polynomial expansion and piecewise linear models. Results Mathematical analysis enabled to construct nonlinear models for estimating the MET result of submaximal exercise test based on average walk velocity (or distance) in the 6MWT. Conclusions Submaximal effort tolerance in COPD patients can be effectively estimated from new, rehabilitation-oriented, nonlinear models based on the generalized MET concept and the 6MWT. PMID:29425213

Safeguards Challenges for Pebble-Bed Reactors (PBRs):Peoples Republic of China (PRC)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Forsberg, Charles W.; Moses, David Lewis

2009-11-01

The Peoples Republic of China (PRC) is operating the HTR-10 pebble-bed reactor (PBR) and is in the process of building a prototype PBR plant with two modular reactors (250-MW(t) per reactor) feeding steam to a single turbine-generator. It is likely to be the first modular hightemperature reactor to be ready for commercial deployment in the world because it is a highpriority project for the PRC. The plant design features multiple modular reactors feeding steam to a single turbine generator where the number of modules determines the plant output. The design and commercialization strategy are based on PRC strengths: (1) amore » rapidly growing electric market that will support low-cost mass production of modular reactor units and (2) a balance of plant system based on economics of scale that uses the same mass-produced turbine-generator systems used in PRC coal plants. If successful, in addition to supplying the PRC market, this strategy could enable China to be the leading exporter of nuclear reactors to developing countries. The modular characteristics of the reactor match much of the need elsewhere in the world. PBRs have major safety advantages and a radically different fuel. The fuel, not the plant systems, is the primary safety system to prevent and mitigate the release of radionuclides under accident conditions. The fuel consists of small (6-cm) pebbles (spheres) containing coatedparticle fuel in a graphitized carbon matrix. The fuel loading per pebble is small (~9 grams of low-enriched uranium) and hundreds of thousands of pebbles are required to fuel a nuclear plant. The uranium concentration in the fuel is an order of magnitude less than in traditional nuclear fuels. These characteristics make the fuel significantly less attractive for illicit use (weapons production or dirty bomb); but, its unusual physical form may require changes in the tools used for safeguards. This report describes PBRs, what is different, and the safeguards challenges. A series of safeguards recommendations are made based on the assumption that the reactor is successfully commercialized and is widely deployed.« less

Reference values for the 6-minute walk test in healthy children and adolescents in Switzerland

PubMed Central

2013-01-01

Background The six-minute walk test (6MWT) is a simple, low tech, safe and well established, self-paced assessment tool to quantify functional exercise capacity in adults. The definition of normal 6MWT in children is especially demanding since not only parameters like height, weight and ethnical background influence the measurement, but may be as crucial as age and the developmental stage. The aim of this study is establishing reference values for the 6MWT in healthy children and adolescents in Switzerland and to investigate the influence of age, anthropometrics, heart rate, blood pressure and physical activity on the distance walked. Methods Children and adolescents between 5–17 years performed a 6MWT. Short questionnaire assessments about their health state and physical activities. anthropometrics and vitals were measured before and after a 6-minute walk test and were previously defined as secondary outcomes. Results Age, height, weight and the heart rate after the 6MWT all predicted the distance walked according to different regression models: age was the best single predictor and mostly influenced walk distance in younger age, anthropometrics were more important in adolescents and females. Heart rate after the 6MWT was an important distance predictor in addition to age and outreached anthropometrics in the majority of subgroups assessed. Conclusions The 6MWT in children and adolescents is feasible and practical. The 6MWT distance depends mainly on age; however, heart rate after the 6MWT, height and weight significantly add information and should be taken into account mainly in adolescents. Reference equations allow predicting 6-minute walk test distance and may help to better assess and compare outcomes in young patients with cardiovascular and respiratory diseases and are highly warranted for different populations. PMID:23915140

Sex-specific predictive power of 6-minute walk test in chronic heart failure is not enhanced using percent achieved of published reference equations.

PubMed

Frankenstein, Lutz; Zugck, Christian; Nelles, Manfred; Schellberg, Dieter; Katus, Hugo; Remppis, Andrew

2008-04-01

The 6-minute walk test (6MWT) is an established prognostic tool in chronic heart failure. The strong influence of height, weight, age, and sex on 6MWT distance may be accounted for by using percentage achieved of predicted value rather than uncorrected 6MWT values. The study included 1069 patients (862 men) with a mean age 55.2 +/- 11.7 years and mean left ventricular ejection fraction of 29% +/- 10%, attending the heart failure clinic of the University of Heidelberg between 1995 and 2005. The predictive power and accuracy of 6MWT and achieved percentage values according to all available published equations for mortality and mortality or transplant combined were tested separately for each sex. The percentage values varied largely between equations. For all equations, women in New York Heart Association (NYHA) functional class I had higher values than men. Although the 6MWT significantly discriminated all NYHA classes for both sexes, only 1 equation discriminated all NYHA classes. No significant differences in the area under the receiver operating-characteristic curve were noted between achieved percentage values and 6MWT. Despite strong univariate significance, achieved percentage values did not retain multivariate significance. The 6MWT was independent from N-terminal brain natriuretic propeptide, NYHA, left ventricular ejection fraction, and peak oxygen uptake. We confirmed 6MWT to be a strong and independent risk predictor for both sexes. Because the prognostic power of 6MWT is not enhanced using percentage achieved of published reference equations, we suggest recalibration of these reference values rather than discarding this approach.

Shuttle walking test and 6-minute walking test induce a similar cardiorespiratory performance in patients recovering from an acute exacerbation of chronic obstructive pulmonary disease.

PubMed

Vagaggini, B; Taccola, M; Severino, S; Marcello, M; Antonelli, S; Brogi, S; De Simone, C; Giardina, A; Paggiaro, P L

2003-01-01

The incremental shuttle walking test (SWT) has recently been proposed as a more valid and reproducible alternative to the conventional 6-min walking test (6MWT) in the evaluation of exercise tolerance in patients with chronic obstructive pulmonary disease (COPD). To compare the cardiorespiratory performance obtained during two sessions of SWT with that obtained during two sessions of 6MWT. We examined 18 patients (forced expiratory volume in 1 s: 48 +/- 14%) recovering from an acute exacerbation of COPD that had required hospitalization. In the same afternoon, each patient performed two SWT and two 6MWT, with an interval of at least 30 min between each test; the sequence of the tests was randomized. Mean walking distance was greater in the second SWT test than in the first SWT. The changes from baseline in systolic blood pressure, heart rate, respiratory rate, oxygen saturation and dyspnea Borg index at the end of the test were similar between the two 6MWT and the two SWT. There was a highly significant correlation between walking distances measured during SWT and during 6MWT (rho: 0.85, p < 0.0005). Neither SWT nor 6MWT correlated with functional data of COPD. SWT, though being considered to be closer to a submaximal exercise test than 6MWT, does not induce a greater cardiorespiratory performance than 6MWT in patients recovering from acute exacerbation of COPD. Copyright 2003 S. Karger AG, Basel

Ring-widths of the above tree-line shrub Rhododendron reveal the change of minimum winter temperature over the past 211 years in Southwestern China

NASA Astrophysics Data System (ADS)

Bi, Yingfeng; Xu, Jianchu; Yang, Jinchao; Li, Zongshan; Gebrekirstos, Aster; Liang, Eryuan; Zhang, Shibao; Yang, Yang; Yang, Yongping; Yang, Xuefei

2017-06-01

Changes in minimum winter temperature (MWT) and their potential effects on plant growth and development have been gaining increased scientific attention. To better understand these changes across long temporal scales, the present study used dendroclimatological techniques to assess variations in MWT in Southwestern China. Using data from Rhododendron species distributed in areas above the tree-line, a regional composite chronology was generated for a 341-year period. Based on the significant negative correlation between MWT values and ring-width, the most reliable parts of this chronological data were then used to reconstruct MWT values for the past 211 years. This reconstructed MWT series showed decadal to multi-decadal fluctuations. Three distinct cold periods prevailed during 1823-1858, 1882-1891 and 1922-1965, while four warm intervals occurred in 1800-1822, 1858-1881, 1892-1921 and 1966-2011. Our reconstructed MWT reveals a warming trend over the most recent eight decades, which is in agreement with instrumental observations. However, the MWT values and rate of warming over the past seven decades did not exceed those found in the reconstructed temperature data for the past 211 years. Spatial correlations reveal that the MWT in Southwest China is strongly associated with regional temperatures in the Eastern and Central Himalaya, Northern China, and the Indian Peninsula. Larger scale climate oscillations of the Western Pacific and Northern Indian Ocean as well as the North Atlantic Oscillation probably influenced the region's temperature in the past.

Psychometric properties of the 30-m walking test in patients with degenerative cervical myelopathy: results from two prospective multicenter cohort studies.

PubMed

Bohm, Parker E; Fehlings, Michael G; Kopjar, Branko; Tetreault, Lindsay A; Vaccaro, Alexander R; Anderson, Karen K; Arnold, Paul M

2017-02-01

The timed 30-m walking test (30MWT) is used in clinical practice and in research to objectively quantify gait impairment. The psychometric properties of 30MWT have not yet been rigorously evaluated. This study aimed to determine test-retest reliability, divergent and convergent validity, and responsiveness to change of the 30MWT in patients with degenerative cervical myelopathy (DCM). A retrospective observational study was carried out. The sample consisted of patients with symptomatic DCM enrolled in the AOSpine North America or AOSpine International cervical spondylotic myelopathy studies at 26 sites. Modified Japanese Orthopaedic Association scale (mJOA), Nurick scale, 30MWT, Neck Disability Index (NDI), and Short-Form-36 (SF-36v2) physical component score (PCS) and mental component score (MCS) were the outcome measures. Data from two prospective multicenter cohort myelopathy studies were merged. Each patient was evaluated at baseline and 6 months postoperatively. Of 757 total patients, 682 (90.09%) attempted to perform the 30MWT at baseline. Of these 682 patients, 602 (88.12%) performed the 30MWT at baseline. One patient was excluded, leaving601 in the analysis. At baseline, 81 of 682 (11.88%) patients were unable to perform the test, and their mJOA, NDI, and SF-36v2 PCS scores were lower compared with those who performed the test at baseline. In patients who performed the 30MWT at baseline, there was very high correlation among the three baseline 30MWT measurements (r=0.9569-0.9919). The 30MWT demonstrated good convergent and divergent validity. It was moderately correlated with the Nurick (r=0.4932), mJOA (r=-0.4424), and SF-36v2 PCS (r=-0.3537) (convergent validity) and poorly correlated with the NDI (r=0.2107) and SF-36v2 MCS (r=-0.1984) (divergent validity). Overall, the 30MWT was not responsive to change (standardized response mean [SRM]=0.30). However, for patients who had a baseline time above the median value of 29 seconds, the SRM was 0.45. The 30MWT shows high test-retest reliability and good divergent and convergent validity. It is responsive to change only in patients with more severe myelopathy. The 30MWT is a simple, quick, and affordable test, and should be used as an ancillary test to evaluate gait parameters in patients with DCM. Copyright © 2016 Elsevier Inc. All rights reserved.

Hockey-stick steam generator for LMFBR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hallinan, G.J.; Svedlund, P.E.

1981-01-01

This paper presents the criteria and evaluation leading to the selection of the Hockey Stick Steam Generator Concept and subsequent development of that concept for LMFBR application. The selection process and development of the Modular Steam Generator (MSG) is discussed, including the extensive test programs that culminated in the manufacture and test of a 35 MW(t) Steam Generator. The design of the CRBRP Steam Generator is described, emphasizing the current status and a review of the critical structural areas. CRBRP steam generator development tests are evaluated, with a discussion of test objectives and rating of the usefulness of test resultsmore » to the CRBRP prototype design. Manufacturing experience and status of the CRBRP prototype and plant units is covered. The scaleup of the Hockey Stick concept to large commercial plant application is presented, with an evaluation of scaleup limitations, transient effects, and system design implications.« less

Pebble bed modular reactor safeguards: developing new approaches and implementing safeguards by design

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beyer, Brian David; Beddingfield, David H; Durst, Philip

2010-01-01

The design of the Pebble Bed Modular Reactor (PBMR) does not fit or seem appropriate to the IAEA safeguards approach under the categories of light water reactor (LWR), on-load refueled reactor (OLR, i.e. CANDU), or Other (prismatic HTGR) because the fuel is in a bulk form, rather than discrete items. Because the nuclear fuel is a collection of nuclear material inserted in tennis-ball sized spheres containing structural and moderating material and a PBMR core will contain a bulk load on the order of 500,000 spheres, it could be classified as a 'Bulk-Fuel Reactor.' Hence, the IAEA should develop unique safeguardsmore » criteria. In a multi-lab DOE study, it was found that an optimized blend of: (i) developing techniques to verify the plutonium content in spent fuel pebbles, (ii) improving burn-up computer codes for PBMR spent fuel to provide better understanding of the core and spent fuel makeup, and (iii) utilizing bulk verification techniques for PBMR spent fuel storage bins should be combined with the historic IAEA and South African approaches of containment and surveillance to verify and maintain continuity of knowledge of PBMR fuel. For all of these techniques to work the design of the reactor will need to accommodate safeguards and material accountancy measures to a far greater extent than has thus far been the case. The implementation of Safeguards-by-Design as the PBMR design progresses provides an approach to meets these safeguards and accountancy needs.« less

[Peak oxygen uptake during the six-minute walk test in diffuse interstitial lung disease and pulmonary hypertension].

PubMed

Blanco, Isabel; Villaquirán, Claudio; Valera, José Luis; Molina-Molina, María; Xaubet, Antoni; Rodríguez-Roisin, Robert; Barberà, Joan A; Roca, Josep

2010-03-01

The six-minute walk test (6MWT) is widely used in evaluating diffuse interstitial lung disease (ILD) and pulmonary hypertension (PH). However, their physiological determining factors have not been well defined. To evaluate the physiological changes that occur in ILD and PH during the 6MWT, and compare them with the cardiopulmonary exercise test (CPET). Thirteen patients with ILD and 14 with PH were studied using the 6MWT and CPET on an ergometer cycle. The respiratory variables were recorded by means of telemetry during the 6MWT. Oxygen consumption (VO(2)), respiratory and heart rate reached a plateau from minute 3 of the 6MWT in both diseases. The VO(2) did not differ from the peak value in the CPET (14+/-2 and 15+/-2 ml/kg/min, respectively, in ILD; 16+/-6 and 16+/-6 ml/kg/min, in PH). The arterial oxygen saturation decreased in both diseases, although it was more marked in ILD (-12+/-5%, p<0,01). The ventilatory equivalent for CO(2) (V(E)/VCO(2)) in PH during the 6MWT was strongly associated with functional class (FC) (85+/-14 in FC III-IV, 44+/-6 in FC I-II; p<0,001). The 6MWT in ILD and PH behaves like a maximal effort test, with similar VO(2) to the CPET, demonstrating a limit in oxygen transport capacity. Monitoring using telemetry during the 6MWT may be useful for the clinical evaluation of patients with ILD or PH. Copyright 2009 SEPAR. Published by Elsevier Espana. All rights reserved.

Importance of Urinary Drug Screening in the Multiple Sleep Latency Test and Maintenance of Wakefulness Test.

PubMed

Anniss, Angela M; Young, Alan; O'Driscoll, Denise M

2016-12-15

Multiple sleep latency testing (MSLT) and the maintenance of wakefulness test (MWT) are gold-standard objective tests of daytime sleepiness and alertness; however, there is marked variability in their interpretation and practice. This study aimed to determine the incidence of positive drug screens and their influence on MSLT, MWT, and polysomnographic variables. All patients attending Eastern Health Sleep Laboratory for MSLT or MWT over a 21-mo period were included in the study. Urinary drug screening for amphetamines, barbiturates, benzodiazepines, cannabinoids, cocaine, methadone, and opiates was performed following overnight polysomnography (PSG). Demographics and PSG variables were compared. Of 69 studies, MSLT (43) and MWT (26), 16% of patients had positive urinary drug screening (7 MSLT; 4 MWT). Drugs detected included amphetamines, cannabinoids, opiates, and benzodiazepines. No patient self-reported use of these medications prior to testing. No demographic, MSLT or MWT PSG data or overnight PSG data showed any statistical differences between positive and negative drug screen groups. Of seven MSLT patients testing positive for drug use, one met criteria for the diagnosis of narcolepsy and five for idiopathic hypersomnia. On MWT, three of the four drug-positive patients had a history of a motor vehicle accident and two patients were occupational drivers. These findings indicate drug use is present in patients attending for daytime testing of objective sleepiness and wakefulness. These data support routine urinary drug screening in all patients undergoing MSLT or MWT studies to ensure accurate interpretation in the context of illicit and prescription drug use. © 2016 American Academy of Sleep Medicine

Comparison of gait performance on different environmental settings for patients with chronic spinal cord injury.

PubMed

Olmos, L E; Freixes, O; Gatti, M A; Cozzo, D A; Fernandez, S A; Vila, C J; Agrati, P E; Rubel, I F

2008-05-01

Observational cross-section study. The objective of our study was to determine if the influence of a community environment would impact on ASIA D spinal cord injured (SCI) gait performance patients. Our main hypothesis is that an outdoor community environment may influence gait speed and endurance on community ambulating patients. Ten-Meter Walking (10MWT) and Six-Minute Walking (6MWT) tests were performed on community ambulating SCI research participants (n=18) in two different environmental conditions: (1) Experimental (indoors Gymnasium) and (2) Natural (community setting). Average gait speed and endurance values were obtained for the two different conditions and analyzed for statistical significance on the nonparametric two-tailed Wilcoxon signed rank test. While no difference was observed on the 10MWT we found an improvement on gait performance on the 6 MWT on a community setting. Our study showed mixed results on environmental influence on gait speed and endurance on ASIA D patient population. While there is no difference on the 10 MWT, there is an improvement on gait performance on the communitary 6MWT.

Physics-based model for predicting the performance of a miniature wind turbine

NASA Astrophysics Data System (ADS)

Xu, F. J.; Hu, J. Z.; Qiu, Y. P.; Yuan, F. G.

2011-04-01

A comprehensive physics-based model for predicting the performance of the miniature wind turbine (MWT) for power wireless sensor systems was proposed in this paper. An approximation of the power coefficient of the turbine rotor was made after the turbine rotor performance was measured. Incorporation of the approximation with the equivalent circuit model which was proposed according to the principles of the MWT, the overall system performance of the MWT was predicted. To demonstrate the prediction, the MWT system comprised of a 7.6 cm thorgren plastic propeller as turbine rotor and a DC motor as generator was designed and its performance was tested experimentally. The predicted output voltage, power and system efficiency are matched well with the tested results, which imply that this study holds promise in estimating and optimizing the performance of the MWT.

Heart rate recovery post 6-minute walking test in obstructive sleep apnea: cycle ergometry versus 6-minute walking test in OSA patients.

PubMed

Cholidou, Kyriaki G; Manali, Effrosyni D; Kapsimalis, Fotis; Kostakis, Ioannis D; Vougas, Konstantinos; Simoes, Davina; Markozannes, Evaggelos; Vogiatzis, Ioannis; Bakakos, Petros; Koulouris, Nikolaos; Alchanatis, Manos

2014-10-01

To examine the clinical usefulness of heart rate recovery (HRR) post 6-minute walking test (6MWT) as a simple marker of cardiovascular risk in obstructive sleep apnea (OSA) patients in comparison to HRR post cycle ergometry, the validated and more sophisticated protocol. Seventy-four participants underwent full overnight polysomnography, cycle ergometry and 6MWT. The HRR at 1, 2 and 3 min (HRR-1, HRR-2 and HRR-3) 6MWT was compared to HRR at 1, 2, and 3 min post cycle ergometry in normal subjects and in moderate and severe OSA patients before and after 6-month CPAP treatment. The HRR-1, HRR-2 and HRR-3 in 6MWT were significantly different between normal, moderate and severe OSA patients with higher rates achieved in normal. The higher the severity of OSA the lower the HRR was. There were also no differences found between work rate and distance walked during cycle ergometry or 6MWT, respectively, concerning normal, moderate and severe OSA patients. Heart rate recovery was further associated with minimum saturation of oxygen during sleep independently of the duration of apnea episodes of BMI and ESS. The treatment with CPAP had a beneficial effect on HRR both post-6MWT and post cycle ergometry. Autonomic nervous system dysfunction in OSA can be found even with submaximal exertion. Heart rate recovery post-6MWT, such as HRR post cycle ergometry, was significantly impaired in OSA patients in comparison to normals and was favorably influenced from CPAP treatment. Furthermore, it was found to be more sensitive compared with distance walked in 6MWT in discriminating severity of OSA. The HRR post-6MWT was found to be an easily measured and reliable marker of OSA severity both before and after CPAP treatment.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qualls, A. L.; Brown, Nicholas R.; Betzler, Benjamin R.

The fluoride salt-cooled high-temperature reactor (FHR) demonstration reactor (DR) is a concept for a salt-cooled reactor with 100 megawatts of thermal output (MWt). It would use tristructural-isotropic (TRISO) particle fuel within prismatic graphite blocks. FLiBe (2 LiF-BeF 2) is the reference primary coolant. The FHR DR is designed to be small, simple, and affordable. Development of the FHR DR is a necessary intermediate step to enable near-term commercial FHRs. Lower risk technologies are purposely included in the initial FHR DR design to ensure that the reactor can be built, licensed, and operated within an acceptable budget and schedule. These technologiesmore » include TRISO particle fuel, replaceable core structural material, the use of that same material for the primary and intermediate loops, and tube-and-shell primary-to-intermediate heat exchangers. Several preconceptual and conceptual design efforts that have been conducted on FHR concepts bear a significant influence on the FHR DR design. Specific designs include the Oak Ridge National Laboratory (ORNL) advanced high-temperature reactor (AHTR) with 3400/1500 MWt/megawatts of electric output (MWe), as well as a 125 MWt small modular AHTR (SmAHTR) from ORNL. Other important examples are the Mk1 pebble bed FHR (PB-FHR) concept from the University of California, Berkeley (UCB), and an FHR test reactor design developed at the Massachusetts Institute of Technology (MIT). The MIT FHR test reactor is based on a prismatic fuel platform and is directly relevant to the present FHR DR design effort. These FHR concepts are based on reasonable assumptions for credible commercial prototypes. The FHR DR concept also directly benefits from the operating experience of the Molten Salt Reactor Experiment (MSRE), as well as the detailed design efforts for a large molten salt reactor concept and its breeder variant, the Molten Salt Breeder Reactor. The FHR DR technology is most representative of the 3400 MWt AHTR concept, and it will demonstrate key operational features of that design. The FHR DR will be closely scaled to the SmAHTR concept in power and flows, so any technologies demonstrated will be directly applicable to a reactor concept of that size. The FHR DR is not a commercial prototype design, but rather a DR that serves a cost and risk mitigation function for a later commercial prototype. It is expected to have a limited operational lifetime compared to a commercial plant. It is designed to be a low-cost reactor compared to more mature advanced prototype DRs. A primary reason to build the FHR DR is to learn about salt reactor technologies and demonstrate solutions to remaining technical gaps.« less

Examination of sustained gait speed during extended walking in individuals with chronic stroke.

PubMed

Altenburger, Peter A; Dierks, Tracy A; Miller, Kristine K; Combs, Stephanie A; Van Puymbroeck, Marieke; Schmid, Arlene A

2013-12-01

To determine if individuals with chronic stroke were able to sustain their peak gait speed during the 6-minute walk test (6MWT), and to explore this sustainability across community ambulation potential subgroups. Prospective cross-sectional study. University-based research laboratory, hospitals, and stroke support groups. A sample of individuals with chronic stroke (N=48) completed a series of questionnaires and physical outcome measures, including gait mat assessment, during a single visit. Not applicable; 1-time cross-sectional data collection. During the 6MWT, we measured peak gait speed and end gait speed to assess sustainability, along with beginning gait speed, total distance walked, and rating of perceived exertion. We also assessed maximum gait speed during the 10-meter walk test (10MWT). Finally, we examined these gait outcomes across the subgroups. During the 6MWT, peak gait speed declined from .89m/s (SD=.38) to an end speed of .82m/s (SD=.36), whereas perceived exertion increased from 7.7 (SD=2.6) to 11.8 (SD=3.6). This peak gait speed was slower than the 10MWT maximum speed of 1.06m/s (SD=.51), but faster than the 6MWT beginning speed of .81m/s (SD=.34). The unlimited community ambulator subgroup was the primary contributor to sustainability differences. Predicting community ambulation potential based on the discrete gait speed from the 10MWT and endurance based on the average from the 6MWT might be incomplete if gait speed sustainability is not also assessed. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Concurrent Validity of Walking Speed Values Calculated via the GAITRite Electronic Walkway and 3 Meter Walk Test in the Chronic Stroke Population

PubMed Central

Peters, Denise M.; Middleton, Addie; Donley, Jonathan W.; Blanck, Erika L.; Fritz, Stacy L.

2014-01-01

The purpose of this study was to provide novel information regarding the concurrent validity (primary aim) and reliability (secondary aim) of walking speed (WS) calculated via the GAITRite1 electronic walkway system and 3 meter walk test (3MWT) in the chronic stroke population. The 3MWT is a feasible option for clinicians working in environments where space is limited. Psychometric properties of the test have not been established. Participants with chronic stroke were stratified into three groups: household ambulators (HA) (self-selected WS <0.4 m/s, 12 participants, 31 observations), limited community ambulators (LCA) (self-selected WS 0.4–0.8 m/s, 24 participants, 60 observations), and community ambulators (CA) (self-selected WS >0.8 m/s, 26 participants, 71 observations). Three consecutive trials of GAITRite1 and 3MWT were performed at participant’s self-selected WS. Average WS measurements differed significantly (p <0.05) between GAITRite1 and 3MWT for all three groups. HA group: GAITRite1 0.25 (0.11) m/s, 3MWT 0.27 (0.11) m/s; LCA group: GAITRite1 0.56 (0.11) m/s, 3MWT 0.52 (0.10) m/s; CA group: GAITRite1 1.03 (0.16) m/s, 3MWT 0.89 (0.15) m/s. Both WS measures had excellent within-session reliability (ICC’s ranging from 0.85 to 0.97, SEM95 from 0.04 to 0.12 m/s, and MDC95 from 0.05 to 0.16 m/s). Reliability was highest for HA on both measures. Although both the 3MWT and the GAITRite1 are reliable measures of WS for individuals with chronic stroke, the two measures do not demonstrate concurrent validity. PMID:24164441

Heart failure: comparison between six-minute walk test and cardiopulmonary test.

PubMed

Carvalho, Eduardo Elias Vieira de; Costa, Daniela Caetano; Crescêncio, Júlio César; Santi, Giovani Luiz De; Papa, Valéria; Marques, Fabiana; Schmidt, André; Marin-Neto, José Antonio; Simões, Marcus Vinícius; Gallo Junior, Lourenço

2011-07-01

Chronic heart failure (HF) is a syndrome characterized by reduced cardiac output in relation to the metabolic needs of the organism, as well as metabolic and neurohormonal axis abnormalities. Symptoms such as fatigue and dyspnoea are notorious and stress tests are widely used to assess functional capacity, prognosis and effectiveness of therapeutic interventions in this syndrome. To evaluate the reproducibility of the six-minute walk test (6MW) in patients with HF and correlate the magnitude of the variables reached at peak exercise of the 6MWT with a cardiopulmonary exercise test (CPET). We studied 16 patients (12 men and 4 women) diagnosed with HF FC I-II (NYHA). The volunteers underwent two 6MWT (6MWT'1 and 6MWT'2) with 30-minute interval between them; then, they underwent a maximum CPET. All variables obtained in the two 6MWT' proved to be significant with high correlations: distance walked (DW) (r = 0.93, p < 0.0001), heart rate (HR) (r = 0.89, p < 0.0001), oxygen consumption (VO2) (r = 0.93, p < 0.0001) and scale of perceived exertion (r = 0.85, p < 0.0001). In turn, all variables analyzed in the 6MWT' showed significant and moderate correlations with the variables obtained from the CPET, namely: peak HR (r = 0.66; p = 0.005); VO2 (r = 0.57; p = 0.02) and VO2 in the CPET and DT in the 6MWT'2 (r = 0.70; p = 0.002). The 6MWT was reproducible in this group of patients with HF (NYHA - I-II) and correlated with the CPET. Therefore, it is a tool for reliable evaluation, and a suitable, safe and low-cost alternative for the prescription of aerobic exercise in patients with HF.

Comparison of two 6-minute walk tests to assess walking capacity in polio survivors.

PubMed

Brehm, Merel-Anne; Verduijn, Suzan; Bon, Jurgen; Bredt, Nicoline; Nollet, Frans

2017-11-21

To compare walking dynamics and test-retest reliability for 2 frequently applied walk tests in polio survivors: the 6-minute walk test (6MWT) to walk as far as possible; and the 6-minute walking energy cost test (WECT) at comfortable speed. Observational study. Thirty-three polio survivors, able to walk ≥ 150 m. On the same day participants performed a 6MWT and a WECT, which were repeated 1-3 weeks later. For each test, distance walked, heart rate and reduction in speed were assessed. The mean distance walked and mean heart rate were significantly higher in the 6MWT (441 m (standard deviation) (SD 79.7); 118 bpm (SD 19.2)) compared with the WECT (366 m (SD 67.3); 103 bpm (SD 14.3)); p< 0.001. Furthermore, during the 6MWT, patients continuously slowed down (-6%), while during the WECT speed dropped only slightly during the first 2 min, by -1.8% in total. Test-retest reliability of both tests was excellent (intraclass correlation coefficient (ICC) ≥ 0.95; lower bound 95% confidence interval (95% CI) ≥ 0.87). The smallest detectable change for the walked distance was 42 m (9.7% change from the mean) and 50 m (13.7%) on the 6MWT and WECT, respectively. Both the 6MWT and the WECT are reliable to assess walking capacity in polio survivors, with slightly superior sensitivity to detect change for the 6MWT. Differences in walking dynamics confirm that the tests cannot be used interchangeably. The 6MWT is recommended for measuring maximal walking capacity and the WECT for measuring submaximal walking capacity.

Maintenance of Wakefulness Test scores and driving performance in sleep disorder patients and controls.

PubMed

Philip, Pierre; Chaufton, Cyril; Taillard, Jacques; Sagaspe, Patricia; Léger, Damien; Raimondi, Monika; Vakulin, Andrew; Capelli, Aurore

2013-08-01

Sleepiness at the wheel is a risk factor for traffic accidents. Past studies have demonstrated the validity of the Maintenance of Wakefulness Test (MWT) scores as a predictor of driving impairment in untreated patients with obstructive sleep apnea syndrome (OSAS), but there is limited information on the validity of the maintenance of wakefulness test by MWT in predicting driving impairment in patients with hypersomnias of central origin (narcolepsy or idiopathic hypersomnia). The aim of this study was to compare the MWT scores with driving performance in sleep disorder patients and controls. 19 patients suffering from hypersomnias of central origin (9 narcoleptics and 10 idiopathic hypersomnia), 17 OSAS patients and 14 healthy controls performed a MWT (4×40-minute trials) and a 40-minute driving session on a real car driving simulator. Participants were divided into 4 groups defined by their MWT sleep latency scores. The groups were pathological (sleep latency 0-19 min), intermediate (20-33 min), alert (34-40 min) and control (>34 min). The main driving performance outcome was the number of inappropriate line crossings (ILCs) during the 40 minute drive test. Patients with pathological MWT sleep latency scores (0-19 min) displayed statistically significantly more ILC than patients from the intermediate, alert and control groups (F (3, 46)=7.47, p<0.001). Pathological sleep latencies on the MWT predicted driving impairment in patients suffering from hypersomnias of central origin as well as in OSAS patients. MWT is an objective measure of daytime sleepiness that appears to be useful in estimating the driving performance in sleepy patients. Copyright © 2013 Elsevier B.V. All rights reserved.

Validity and Responsiveness of the Two-Minute Walk Test for Measuring Functional Recovery After Total Knee Arthroplasty.

PubMed

Unnanuntana, Aasis; Ruangsomboon, Pakpoom; Keesukpunt, Worawut

2018-06-01

The 2-minute walk test (2mwt) is a performance-based test that evaluates functional recovery after total knee arthroplasty (TKA). This study evaluated its validity compared with the modified Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Oxford Knee Score (OKS), modified Knee Score, Numerical Pain Rating Scale, and Timed Up and Go test, and its responsiveness in assessing functional recovery in TKA patients. This prospective cohort study included 162 patients undergoing primary TKA between 2013 and 2015. We used patient-reported outcome measures (modified WOMAC, OKS, modified Knee Score, Numerical Pain Rating Scale) and performance-based tests (2mwt and Timed Up and Go test) at baseline and 3, 6, and 12 months postoperatively. The construct validity of 2mwt was determined between the 2mwt distances walked and other outcome measurements. To assess responsiveness, effect size and standardized response mean were analyzed. Minimal clinically important difference of 2mwt at 12 months after TKA was also calculated. All outcome measurements improved significantly from baseline to 3, 6, and 12 months postoperatively. Bivariate analysis revealed mild to moderate associations between the 2mwt and modified WOMAC function subscales, and moderate to strong associations with OKS. Mild to moderate correlations were found for pain and stiffness between 2mwt and other outcome measurements. The effect size and standardized response mean at 12 months were large, with a minimal clinically important difference of 12.7 m. 2mwt is a validated performance-based test with responsiveness properties. Being simple and easy to perform, it can be used routinely in clinical practice to evaluate functional recovery after TKA. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Walk test and school performance in mouth-breathing children.

PubMed

Boas, Ana Paula Dias Vilas; Marson, Fernando Augusto de Lima; Ribeiro, Maria Angela Gonçalves de Oliveira; Sakano, Eulália; Conti, Patricia Blau Margosian; Toro, Adyléia Dalbo Contrera; Ribeiro, José Dirceu

2013-01-01

In recent decades, many studies on mouth breathing (MB) have been published; however, little is known about many aspects of this syndrome, including severity, impact on physical and academic performances. Compare the physical performance in a six minutes walk test (6MWT) and the academic performance of MB and nasal-breathing (NB) children and adolescents. This is a descriptive, cross-sectional, and prospective study with MB and NB children submitted to the 6MWT and scholar performance assessment. We included 156 children, 87 girls (60 NB and 27 MB) and 69 boys (44 NB and 25 MB). Variables were analyzed during the 6MWT: heart rate (HR), respiratory rate, oxygen saturation, distance walked in six minutes and modified Borg scale. All the variables studied were statistically different between groups NB and MB, with the exception of school performance and HR in 6MWT. MB affects physical performance and not the academic performance, we noticed a changed pattern in the 6MWT in the MB group. Since the MBs in our study were classified as non-severe, other studies comparing the academic performance variables and 6MWT are needed to better understand the process of physical and academic performances in MB children.

Relationships between heart rate target determined in different exercise testing in COPD patients to prescribed with individualized exercise training

PubMed Central

Fabre, Claudine; Chehere, Baptiste; Bart, Frédéric; Mucci, Patrick; Wallaert, Benoit; Grosbois, Jean Marie

2017-01-01

Background It has been scientifically proven that pulmonary rehabilitation improves exercise tolerance and facilitates the carrying out of daily physical activities. To optimize the physical and physiological benefits, it is necessary to individualize the training intensity for each patient. The aim of this study is to compare the heart rate (HR) responses to three exercise modalities measuring aerobic fitness in chronic obstructive pulmonary disease patients, in order to easily prescribe individual target HRs for endurance training. Patients and method Fifty COPD patients (mean age: 60.1±8.5 years) were included in the study. Each patient carried out a cardiopulmonary exercise test, a 6-minute walk test (6MWT) and a 6-minute stepper test (6MST). During these tests, HR was recorded continuously. After the cardiopulmonary exercise test, the HR was noted at the ventilatory threshold (VT) and at the end of the two exercise field tests (6MWTpeak and 6MSTpeak). The values of the HR during the last 3 minutes of both field tests were averaged (6MWT456 and 6MST456). Finally, the HR at 60% of the HR reserve was calculated with the values of the HR measured during 6MWT and 6MST (HRr60%walk, HRr60%step). Results The HRs measured during the 6MST were significantly higher than those measured during the 6MWT. The HRr60%step was not significantly different from 6MWT456 and 6MWTpeak HR (P=0.51; P=0.48). A significant correlation was observed between 6MWT456 and 6MWTpeak (r=0.58). The 6MWT456 and 6MWTpeak HR were correlated with HRr60%step (r=0.68 and r=0.62). The VT could be determined in 28 patients. The HRVT was not different from 6MWT456, 6MWTpeak, and HRr60%step (P=0.57, P=0.41 and P=0.88) and was correlated to 6MWT456, 6MWTpeak, and HRr60%step (r=0.45, r=0.40, r=0.48). Conclusion An individualized target HR for endurance training can be prescribed from the HR measured during routine tests, such as 6MWT or 6MST. PMID:28553100

Preparation of high temperature gas-cooled reactor fuel element

DOEpatents

Bradley, Ronnie A.; Sease, John D.

1976-01-01

This invention relates to a method for the preparation of high temperature gas-cooled reactor (HTGR) fuel elements wherein uncarbonized fuel rods are inserted in appropriate channels of an HTGR fuel element block and the entire block is inserted in an autoclave for in situ carbonization under high pressure. The method is particularly applicable to remote handling techniques.

Repeatability and responsiveness of exercise tests in pulmonary arterial hypertension.

PubMed

Mainguy, Vincent; Malenfant, Simon; Neyron, Anne-Sophie; Bonnet, Sébastien; Maltais, François; Saey, Didier; Provencher, Steeve

2013-08-01

Exercise tolerance in pulmonary arterial hypertension (PAH) is most commonly assessed by the 6-min walk test (6MWT). Whether endurance exercise tests are more responsive than the 6MWT remains unknown. 20 stable PAH patients (mean±sd age 53±15 years and mean pulmonary arterial pressure 44±16 mmHg) already on PAH monotherapy completed the 6MWT, the endurance shuttle walk test (ESWT) and the cycle endurance test (CET) before and after the addition of sildenafil citrate 20 mg three times daily or placebo for 28 days in a randomised double-blind crossover setting. Pre- or post-placebo tests were used to assess repeatability of each exercise test, whereas pre- or post-sildenafil citrate tests were used to assess their responsiveness. Sildenafil citrate led to placebo-corrected changes in exercise capacity of 18±25 m (p = 0.02), 58±235 s (p = 0.58) and 29±77 s (p = 0.09) for the 6MWT, the ESWT and the CET, respectively. The 6MWT was associated with a lower coefficient of variation between repeated measures (3% versus 18% versus 13%), resulting in a higher standardised response mean compared with endurance tests (0.72, 0.25 and 0.38 for the 6MWT, the ESWT and the CET, respectively). The 6MWT had the best ability to capture changes in exercise capacity when sildenafil citrate was combined with patients' baseline monotherapy, supporting its use as an outcome measure in PAH.

The 6-minute walking test and all-cause mortality in patients undergoing a post-cardiac surgery rehabilitation program.

PubMed

La Rovere, Maria Teresa; Pinna, Gian Domenico; Maestri, Roberto; Olmetti, Francesca; Paganini, Vincenzo; Riccardi, Giorgio; Riccardi, Roberto; Goggi, Claudio; Ranucci, Marco; Febo, Oreste

2015-01-01

The 6-minute walking test (6mWT) is used to prescribe physical activity in cardiac surgery patients. The clinical value of a pre-discharge 6mWT and its association with outcome is not well defined. We retrospectively analyzed data from 313 patients (age 66 ± 11 years, 23% females, left ventricular ejection fraction (LVEF) 52 ± 11%, Hb 10.5 ± 1.3 g/dl, serum albumin 3.9 ± 0.4 mg/dl) who were admitted to our rehabilitation institute following cardiac surgery. A 6mWT was performed at entry and at discharge and expressed as % of theoretical predicted values calculated on the basis of individual age, height, weight and sex. The endpoint was represented by all-cause mortality. The predictive value of 6mWT was tested in univariate and multivariate analysis. A pre-discharge 6mWT was completed by 284 out of 313 patients. Two patients died in hospital. During a median of 23 months, mortality was 9% (26/284) and 44% (12/27) (p < 0.0001) in patients who did or did not perform the pre-discharge 6mWT. The distance covered at the pre-discharge 6mWT as a continuous variable of % predicted values was a significant predictor of subsequent mortality (Hazard Ratio (HR) 0.97 (95% CI 0.96-0.99), p = 0.0019). After adjustment for all preselected covariates, the pre-discharge 6mWT (HR 0.97 (95% CI 0.95-0.99), p = 0.0038) and LVEF (HR 0.93 (95% CI 0.90-0.96), p < 0.0001) remained significantly associated with the outcome. In recent cardiac surgery patients, the pre-discharge 6mWT is not only a valid measurement of the impact of cardiac rehabilitation but also provides outcome information offering the possibility to identify patients who may need more intensive follow-up. © The European Society of Cardiology 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Very high temperature behavior of HTGR core materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soo, P.; Uneberg, G.; Sabatini, R.

1978-01-01

A description is given of experiments to investigate the behavior of HTGR core materials during hypothetical heatup accidents in which the core temperature is assumed to reach values between 2400/sup 0/C and the graphite sublimation range (>3600/sup 0/C). The work includes BISO coated fuel particle failure, simulated fission product migration in core graphite, and graphite sublimation behavior.

COL Application Content Guide for HTGRs: Revision to RG 1.206, Part 1 - Status Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wayne Moe

2012-08-01

A combined license (COL) application is required by the Nuclear Regulatory Commission (NRC) for all proposed nuclear plants. The information requirements for a COL application are set forth in 10 CFR 52.79, “Contents of Applications; Technical Information in Final Safety Analysis Report.” An applicant for a modular high temperature gas-cooled reactor (HTGR) must develop and submit for NRC review and approval a COL application which conforms to these requirements. The technical information necessary to allow NRC staff to evaluate a COL application and resolve all safety issues related to a proposed nuclear plant is detailed and comprehensive. To this, Regulatorymore » Guide (RG) 1.206, “Combined License Applications for Nuclear Power Plants” (LWR Edition), was developed to assist light water reactor (LWR) applicants in incorporating and effectively formatting required information for COL application review (Ref. 1). However, the guidance prescribed in RG 1.206 presumes a LWR design proposal consistent with the systems and functions associated with large LWR power plants currently operating under NRC license.« less

1170 MW/sub t/ HTGR steamer cogeneration plant: design and cost study

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

A conceptual design and cost study is presented for intermediate size high temperature gas-cooled reactor (HTGR) for industrial energy applications performed by United Engineers and Constructors Inc., (UE and C) and The General Atomic Company (GAC). The study is part of a program at ORNL and has the objective to provide support in the evaluation of the technical and economic feasibility of a single unit 1170 MW/sub t/ HTGR steam cycle cogeneration plant (referred to as the Steamer plant) for the production of industrial process energy. Inherent in the achievement of this objective, it was essential to perform a numbermore » of basic tasks such as the development of plant concept, capital cost estimate, project schedule and annual operation and maintenance (O and M) cost.« less

Replacement of the 6-Min Walk Test With Glittre ADL Test and Scores From the PFSDQ-M and HAP Questionnaires in the BODE Index.

PubMed

Moreira, Fabiana B R; de Fuccio, Marcelo B; Ribeiro-Samora, Giane Amorim; Velloso, Marcelo

2018-05-01

Chronic obstructive pulmonary disease reduces functional capacity, which is strongly correlated with the morbidity and mortality of patients. The BODE index considers the multifactorial nature of the disease, including the functional capacity measured by the 6-min walk test (6MWT), and this index predicts the mortality in patients with chronic obstructive pulmonary disease. Our aim was to assess whether association exists between the original BODE index and the modified BODE index by replacing the 6MWT with the scores from the Pulmonary Functional Status and Dyspnea Questionnaire-Modified version (PFSDQ-M), Human Activity Profile (HAP) questionnaire, and the results of the Glittre ADL Test (TGlittre). Twenty-eight subjects diagnosed with chronic obstructive pulmonary disease underwent the 6MWT and TGlittre and responded to the PFSDQ-M and HAP questionnaires. Four BODE index scores were obtained: 1 calculated by using the original method (ie, using the 6MWT) and 3 others calculated by using the results obtained from the TGlittre, PFSDQ-M, and HAP (the modified BODE index scores). High levels of association were observed between the original BODE index and the BODE TGlittre (R = 0.824, P ≤ .0001), BODE PFSDQ-M (R = 0.803, P ≤ .0001), and BODE HAP (R = 0.500, P ≤ .0001). The BODE TGlittre, and BODE PFSDQ-M may be used as alternatives to the 6MWT when physical space is not available to perform the 6MWT or when the condition of a patient does not allow performance of the 6MWT.

Six minute walk test predicts long-term all-cause mortality and heart failure rehospitalization in African-American patients hospitalized with acute decompensated heart failure.

PubMed

Alahdab, M Tarek; Mansour, Ibrahim N; Napan, Sirikarn; Stamos, Thomas D

2009-03-01

The prognostic value of the 6-minute walk test (6MWT) has been described in patients with heart failure (HF); however, limited data are available in an African-American (AA) population. We prospectively evaluated the usefulness of the 6MWT in predicting mortality and HF rehospitalization in AA patients with acute decompensated HF. Two hundred AA patients (63.1% men, mean age 55.7 +/- 12.9 years) with acute decompensated HF were prospectively studied. Patients were followed to assess 40-month all-cause mortality and 18-month HF rehospitalization. The median distance walked on the 6MWT was 213 m. Of the 198 patients with available mortality data, 59 patients (29.8%) died. Of the 191 patients with available rehospitalization data, 114 (59.7%) were rehospitalized for worsening HF. For patients who walked 200 m (P = .001). For patients who walked 200 m (P = .027). Multivariate Cox regression analysis showed that 6MWT distance

Concurrent validity of walking speed values calculated via the GAITRite electronic walkway and 3 meter walk test in the chronic stroke population.

PubMed

Peters, Denise M; Middleton, Addie; Donley, Jonathan W; Blanck, Erika L; Fritz, Stacy L

2014-04-01

The purpose of this study was to provide novel information regarding the concurrent validity (primary aim) and reliability (secondary aim) of walking speed (WS) calculated via the GAITRite electronic walkway system and 3 meter walk test (3MWT) in the chronic stroke population. The 3MWT is a feasible option for clinicians working in environments where space is limited. Psychometric properties of the test have not been established. Participants with chronic stroke were stratified into three groups: (1) household ambulators (HA) (self-selected WS < 0.4 m/s, 12 participants, 31 observations); (2) limited community ambulators (LCA) (self-selected WS 0.4-0.8 m/s, 24 participants, 60 observations); and (3) community ambulators (CA) (self-selected WS > 0.8 m/s, 26 participants, 71 observations). Three consecutive trials of GAITRite and 3MWT were performed at participant's self-selected WS. Average WS measurements differed significantly (p < 0.05) between GAITRite and 3MWT for all three groups. HA group: GAITRite 0.25 (0.11) m/s, 3MWT 0.27 (0.11) m/s; LCA group: GAITRite 0.56 (0.11) m/s, 3MWT 0.52 (0.10) m/s; CA group: GAITRite 1.03 (0.16) m/s, 3MWT 0.89 (0.15) m/s. Both WS measures had excellent within-session reliability (ICC's ranging from 0.85 to 0.97, SEM95 from 0.04 to 0.12 m/s and MDC95 from 0.05 to 0.16 m/s). Reliability was highest for HA on both measures. Although both the 3MWT and the GAITRite are reliable measures of WS for individuals with chronic stroke, the two measures do not demonstrate concurrent validity.

What is the association between left ventricular diastolic dysfunction and 6-minute walk test in hypertensive patients?

PubMed

Farag, El-Sayed M; Al-Daydamony, Mohammad M; Gad, Marwa M

2017-03-01

Heart failure (HF) is a major health problem. Hypertension is an important cause of HF. Most hypertensive patients have some degree of left ventricular (LV) diastolic dysfunction. The 6-minute walk test (6MWT) provides objective data about the exercise tolerance. We aimed to find the association between the degree of LV diastolic dysfunction and the functional capacity assessed by 6MWT in hypertensive patients. The study included 200 asymptomatic hypertensive patients. All patients had undergone full history taking, complete clinical examination, electrocardiography, echocardiography for assessment of LV dimensions, systolic and diastolic dysfunction, and 6MWT. Patients were classified into two groups according to the presence or absence of LV diastolic dysfunction. Clinical and echocardiographic data were comparable between the two groups. Regarding 6MWT, at the end of the test, patients with diastolic dysfunction had significantly higher systolic (P = .0088) and diastolic (P = .019) blood pressure and higher Borg score for dyspnea (P < .00001). The distant walked and percentage of the distance to predicted value were significantly lower in patients with diastolic dysfunction (P = .0322 and .0002, respectively). Incidence of abnormal 6MWT was significantly higher in patients with diastolic dysfunction (P = .00041). Compared to patients with grades I and II, patients with grade III diastolic dysfunction had significantly higher Borg score (P = .013), lower distance walked (P = .039), and lower percentage of distance to predicted vale (P = .009). Independent predictors for abnormal 6MWT were as follows: E/E' ≥15 (P = .0022), E'/A' <1 (P = .0081), and deceleration time of E-wave <160 (P = .013). The presence of LV diastolic dysfunction in hypertensive patients has a bad effect on 6MWT. The degree of LV diastolic dysfunction was correlated with 6MWT results. It may be important to investigate LV diastolic function in asymptomatic hypertensive patients. Copyright © 2017 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

Maggot therapy for chronic ulcer: a retrospective cohort and a meta-analysis.

PubMed

Wilasrusmee, Chumpon; Marjareonrungrung, Mongkol; Eamkong, Suwannee; Attia, John; Poprom, Napaphat; Jirasisrithum, Sopon; Thakkinstian, Ammarin

2014-07-01

Maggot wound therapy (MWT) has been used in various wounds including diabetic foot ulcers, venous leg ulcers, pressure ulcers, and acute surgical wounds. However, the efficacy of MWT therapy has been controversial. We therefore conducted a cohort study and a meta-analysis to assess MWT effects. A retrospective cohort study was performed in diabetic foot ulcer (DFU) patients who were treated with MWT or conventional wound therapy (CWT) in Thailand. The Kaplan-Meier curve was applied to estimate the healing probability. A meta-analysis was performed to pool our study with four previous cohort studies identified from Medline and Scopus. The estimated incidence of wound healing was 5.7/100 (95% CI: 4.49, 7.32) patients-week, and the median time to healing was 14 weeks. The hazard ratio (HR) of wound healing was 7.87 times significantly higher in the MWT than the CWT (p < 0.001) after adjusting for duration and size of ulcers, ankle brachial index (ABI), and glycated hemoglobin (HbA1c). Meta-analysis was applied and suggested that the treatment effects were moderately heterogeneous {Chi-square = 6.18 [degrees of freedom (d.f.) = 4]; p = 0.186; I(2) = 35.2%}, with the pooled risk ratio (RR) of 1.77 [95% confidence intervals (CI) = 1.01, 3.11], i.e., the chance of wound healing was 20% significantly higher with MWT than CWT. The average costs of treatment in patients with DFU were lower in the MWT group than in the CWT group, with medians of US$292.82 and US$490, respectively. Our evidence suggests that MWT is significantly better for wound healing and more cost-effective than CWT. An updated meta-analysis or large scale randomized controlled trial (RCT) is required to confirm this effect. Copyright © 2013. Published by Elsevier B.V.

Role of nuclear grade graphite in controlling oxidation in modular HTGRs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Windes, Willaim; Strydom, G.; Kane, J.

2014-11-01

The passively safe High Temperature Gas-cooled Reactor (HTGR) design is one of the primary concepts considered for Generation IV and Small Modular Reactor (SMR) programs. The helium cooled, nuclear grade graphite moderated core achieves extremely high operating temperatures allowing either industrial process heat or electricity generation at high efficiencies. In addition to their neutron moderating properties, nuclear grade graphite core components provide excellent high temperature stability, thermal conductivity, and chemical compatibility with the high temperature nuclear fuel form. Graphite has been continuously used in nuclear reactors since the 1940’s and has performed remarkably well over a wide range of coremore » environments and operating conditions. Graphite moderated, gas-cooled reactor designs have been safely used for research and power production purposes in multiple countries since the inception of nuclear energy development. However, graphite is a carbonaceous material, and this has generated a persistent concern that the graphite components could actually burn during either normal or accident conditions [ , ]. The common assumption is that graphite, since it is ostensibly similar to charcoal and coal, will burn in a similar manner. While charcoal and coal may have the appearance of graphite, the internal microstructure and impurities within these carbonaceous materials are very different. Volatile species and trapped moisture provide a source of oxygen within coal and charcoal allowing them to burn. The fabrication process used to produce nuclear grade graphite eliminates these oxidation enhancing impurities, creating a dense, highly ordered form of carbon possessing high thermal diffusivity and strongly (covalently) bonded atoms.« less

Nuclear Electric Magnetohydrodynamic Propulsion for Submarine

DTIC Science & Technology

1989-05-01

develop - ment strategies for the future. The base program includes the development of the LMFBR, and HTGR to...events. Oxide fuel is -134- being retained as a backup, pending the outcome of the metal fuel development program . The design allows for a quick fuel ... HTGR plants can be developed with much higher source temperature and core power density. High efficiency and low power den- sity characteristics

Study protocol: effect of playful training on functional abilities of older adults - a randomized controlled trial.

PubMed

Jessen, Jari Due; Lund, Henrik Hautop

2017-01-19

Loss of functional capabilities due to inactivity is one of the most common reasons for fall accidents, and it has been well established that loss of capabilities can be effectively reduced by physical activity. Pilot studies indicate a possible improvement in functional abilities of community dwelling elderly as a result of short-term playing with an exergame system in the form of interactive modular tiles. Such playful training may be motivational to perform and viewed by the subjects to offer life-fulfilling quality, while providing improvement in physical abilities, e.g. related to prevent fall accidents. The RCT will test for a variety of health parameters of community-dwelling elderly playing on interactive modular tiles. The study will be a single blinded, randomized controlled trial with 60 community-dwelling adults 70+ years. The trial will consist an intervention group of 30 participants training with the interactive modular tiles, and a control group of 30 participants that will receive the usual care provided to non-patient elderly. The intervention period will be 12 weeks. The intervention group will perform group training (4-5 individuals for 1 h training session with each participant receiving 13 min training) on the interactive tiles twice a week. Follow-up tests include 6-min Walk Test (6MWT), the 8-ft Timed Up & Go Test (TUG), and the Chair-Stand Test (CS) from the Senior Fitness Test, along with balancing tests (static test on Wii Board and Line Walk test). Secondary outcomes related to adherence, motivation and acceptability will be investigated through semi-structured interviews. Data will be collected from pre- and post-tests. Data will be analyzed for statistically significant differences by checking that there is a Gaussian distribution and then using paired t-test, otherwise using Wilcoxon signed-rank test. "Intention to treat" analysis will be done. The trial tests for increased mobility, agility, balancing and general fitness of community-dwelling elderly as a result of playing, in this case on modular interactive tiles. A positive outcome may help preventing loss of functional capabilities due to inactivity. ClinicalTrials.gov: Nr. NCT02496702 , Initial Release date 7/7-2015.

Prognostic value of serial six-minute walk tests using tele-accelerometry in patients with chronic heart failure: A pre-specified sub-study of the TIM-HF-Trial.

PubMed

Prescher, Sandra; Schoebel, Christoph; Koehler, Kerstin; Deckwart, Oliver; Wellge, Brunhilde; Honold, Marcus; Hartmann, Oliver; Winkler, Sebastian; Koehler, Friedrich

2016-10-01

The six-minute walk test (6MWT) is an established functional test assessing exercise capacity and is used to predict clinical prognosis in patients with chronic heart failure (HF). Tele-accelerometry is a novel approach to activity monitoring using telemedical data transfer and allows a Tele-6MWT to be performed in an outpatient setting. It offers patients the option of performing simple serial follow-up tests in their own home. The aim of this study was to investigate the prognostic value of serial Tele-6MWTs using tele-accelerometry in patients with HF. In this proof-of-concept study, 155 patients with HF completed the Tele-6MWT in an outdoor setting once per month over a period of 0.25-21 months. We analysed the differences in the number of steps over time to predict hospitalization as a result of HF or death. Patients with at least one event (n = 31) recorded a lower number of steps and a shorter distance in Tele-6MWT at baseline compared with patients who remained event-free (n = 124) (540.1 ± 78.4 steps vs. 601.8 ± 76.7 steps, P < 0.001 respectively; 353.2 ± 82.4 m vs. 418.8 ± 95.6 m, P < 0.001). Patients (n = 19) who performed more than one Tele-6MWT prior to a clinical event showed no significant difference in the number of steps, regardless of whether the baseline test was compared with the last Tele-6MWT before the event or with the last two tests before the event. Tele-6MWT has a high predictive value with respect to hospitalization as a result of HF or death from any cause and the results were comparable with the prognostic impact of a conventional 6MWT. Therefore Tele-6MWT may be used as alternative test method in the home environment. However, there is no added prognostic value of repeating Tele-6MWTs on a monthly basis. © The European Society of Cardiology 2016.

The 20-min trial of the maintenance of wakefulness test is profoundly affected by motivation.

PubMed

Shreter, Roni; Peled, Ron; Pillar, Giora

2006-12-01

Assessment of the ability to maintain wakefulness, although very important both for research and for clinical purposes, is still equivocal. The current gold standard is considered the Maintenance of Wakefulness Test (MWT), although there are two different potential protocols to perform it and the normal reference range has been determined on selected populations. The effect of potential "penalty" on failing the test (i.e., presenting sleepiness) has not been seriously studied. We therefore planned this study to examine the effect of motivation on the MWT results in a potentially sleepy population. We hypothesized that with the knowledge that participants may lose their driving license if they fail the test, the results would indicate significantly less sleepiness than reported for other populations. Fifty-four consecutive subjects at high risk of sleepiness referred to the sleep laboratory for evaluation of their ability to maintain wakefulness were studied. All were referred by the National Council for Driving Safety, knowing that if they failed the test, their driving license would not be renewed. Referral reasons were previously diagnosed: obstructive sleep apnea (OSA; 43%), sleep-related accident (7%), or other causes to suspect sleepiness. All underwent a full-night polysomnography (PSG) followed by MWT, five trials of 20 min each (MWT20). Of the 54 participants, 13 were treated for OSA and 28 had untreated OSA, 21 of them had severe OSA (Respiratory Disturbance Index > 30/h). Seventy-four percent of the participants had a BMI >30 kg/m2. Only 5 of the participants fell asleep in any of the MWT trials (one to five trials), which could not be predicted by severity of OSA, age, BMI, or variables derived from the previous night PSG. Of the 21 patients with severe untreated OSA, only 1 patient fell asleep during the MWT20. We conclude that motivation profoundly affects the MWT results, raising the question what should be considered normal or abnormal when sleepy results may cause penalty or other practical implications. In addition, we believe that these results suggest that for renewal of driving license purposes, the MWT20 is insufficient. We speculate that MWT40, with tighter cutoff threshold, would be a more effective tool.

Effect of 6-min Walk Test on pro-BNP Levels in Patients with Pulmonary Arterial Hypertension.

PubMed

Pathak, Vikas; Aris, Robert; Jensen, Brian C; Huang, Wei; Ford, Hubert James

2018-06-01

Plasma pro-BNP (brain natriuretic peptide) levels are often elevated in response to right ventricular (RV) volume and pressure overload, parameters potentially affected by exercise. Plasma pro-BNP levels change in association with long-term changes in pulmonary hemodynamics, thereby serving as a potential biomarker in pulmonary arterial hypertension (PAH). The 6-min Walk Test (6MWT) and pro-BNP level are often checked in a single office visit. There is no universal standard for measuring Pro-BNP levels relative to the timing of the 6MWT. Based on the studies in normal subjects indicating that pro-BNP levels changes after exercise, we hypothesized that the pro-BNP might rise after the 6MWT in PAH patients, potentially impacting clinical decisions. Patients at our center with WHO Group 1 PAH on active therapy at a stable dose for 30 days or more were enrolled. After resting the patient for 30 min, blood was drawn for baseline pro-BNP and a 6MWT was performed. Pro-BNP levels were drawn immediately after the 6MWT and 1 and 2 h later. Pro-BNP was measured using a commercially available ELISA kit. The levels before exercise and after exercise were compared using student's paired t tests. There were 17 females and 3 male subjects. The mean age was 53 ± 11 years. Seven patients had systemic lupus erythematosus-related PAH, six had idiopathic PAH, three had scleroderma, three had portopulmonary hypertension, and one had HIV-related PAH. The mean PA pressure was 50 ± 15 mmHg with a mean pulmonary vascular resistance of 10 ± 4 Wood units. The majority of the patients were on multimodality PAH therapy, including parenteral prostacyclins. Mean 6MWT distance was 377 ± 140 m. In 14/20 patients, the pro-BNP level increased immediately after the 6MWT; in 12/20 patients, the pro-BNP level was elevated at 1 h post exercise. In the majority of the patients, the pro-BNP fell to baseline 2 h post 6MWT. There appears to be a trend of pro-BNP level increasing immediately after exercise and continuing to be elevated at 1 h. Pro-BNP levels then return to baseline at 2 h post 6MWT.

Heat transfer with hockey-stick steam generator. [LMFBR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moody, E; Gabler, M J

1977-11-01

The hockey-stick modular design concept is a good answer to future needs for reliable, economic LMFBR steam generators. The concept was successfully demonstrated in the 30 Mwt MSG test unit; scaled up versions are currently in fabrication for CRBRP usage, and further scaling has been accomplished for PLBR applications. Design and performance characteristics are presented for the three generations of hockey-stick steam generators. The key features of the design are presented based on extensive analytical effort backed up by extensive ancillary test data. The bases for and actual performance evaluations are presented with emphasis on the CRBRP design. The designmore » effort on these units has resulted in the development of analytical techniques that are directly applicable to steam generators for any LMFBR application. In conclusion, the hockey-stick steam generator concept has been proven to perform both thermally and hydraulically as predicted. The heat transfer characteristics are well defined, and proven analytical techniques are available as are personnel experienced in their use.« less

One minute sit-to-stand test is an alternative to 6MWT to measure functional exercise performance in COPD patients.

PubMed

Reychler, Gregory; Boucard, Eliott; Peran, Loïc; Pichon, Romain; Le Ber-Moy, Catherine; Ouksel, Hakima; Liistro, Giuseppe; Chambellan, Arnaud; Beaumont, Marc

2018-03-01

Chronic obstructive pulmonary disease (COPD) is frequently associated with a reduced functional exercise performance. Even if this parameter is routinely evaluated using 6-minute walking test (6MWT), new field tests are regularly investigated as alternative tests. The aim of this study was to compare functional exercise performance evaluation by sit-to-stand test (STST) and 6MWT and to evaluate reliability and repeatability of the STST in COPD patients. Forty-two COPD patients performed randomly two tests: 6MWT and STST. Each test was repeated two times. Distance (6MWD) and number of repetitions were measured. Cardiorespiratory parameters, dyspnea and lower limb fatigue (Borg) were recorded before and after the tests. Sit-to-stand repetitions (19 ± 6) and 6MWD (441 ± 104 m) were correlated (r = .716; P < .001). Good repeatability was found for STST and 6MWT. Good reliability was observed for STST (ICC = 0.902). Variations of heart rate and pulsed oxygen saturation were significantly different between these two tests (23% ± 17% vs 13% ± 11%; P = .022 and -7.6% ± 4.6% vs -0.7% ± 2.7%; P < .001 for 6MWT and STST, respectively). Variations of dyspnea and lower limb fatigue were similar between both tests (P = .827 and P = .467). The one minute sit-to-stand test is a valuable alternative to 6MWT to estimate functional exercise performance in COPD patients. The cardiorespiratory demand is different between both tests although the variation of dypsnea is similar. No learning effect was observed for STST. © 2017 John Wiley & Sons Ltd.

Are the average gait speeds during the 10meter and 6minute walk tests redundant in Parkinson disease?

PubMed

Duncan, Ryan P; Combs-Miller, Stephanie A; McNeely, Marie E; Leddy, Abigail L; Cavanaugh, James T; Dibble, Leland E; Ellis, Terry D; Ford, Matthew P; Foreman, K Bo; Earhart, Gammon M

2017-02-01

We investigated the relationships between average gait speed collected with the 10Meter Walk Test (Comfortable and Fast) and 6Minute Walk Test (6MWT) in 346 people with Parkinson disease (PD) and how the relationships change with increasing disease severity. Pearson correlation and linear regression analyses determined relationships between 10Meter Walk Test and 6MWT gait speed values for the entire sample and for sub-samples stratified by Hoehn & Yahr (H&Y) stage I (n=53), II (n=141), III (n=135) and IV (n=17). We hypothesized that redundant tests would be highly and significantly correlated (i.e. r>0.70, p<0.05) and would have a linear regression model slope of 1 and intercept of 0. For the entire sample, 6MWT gait speed was significantly (p<0.001) related to the Comfortable 10 Meter Walk Test (r=0.75) and Fast 10Meter Walk Test (r=0.79) gait speed, with 56% and 62% of the variance in 6MWT gait speed explained, respectively. The regression model of 6MWT gait speed predicted by Comfortable 10 Meter Walk gait speed produced slope and intercept values near 1 and 0, respectively, especially for participants in H&Y stages II-IV. In contrast, slope and intercept values were further from 1 and 0, respectively, for the Fast 10Meter Walk Test. Comfortable 10 Meter Walk Test and 6MWT gait speeds appeared to be redundant in people with moderate to severe PD, suggesting the Comfortable 10 Meter Walk Test can be used to estimate 6MWT distance in this population. Copyright © 2016 Elsevier B.V. All rights reserved.

Relation of exercise capacity with lung volumes before and after 6-minute walk test in subjects with COPD.

PubMed

Wibmer, Thomas; Rüdiger, Stefan; Kropf-Sanchen, Cornelia; Stoiber, Kathrin M; Rottbauer, Wolfgang; Schumann, Christian

2014-11-01

There is growing evidence that exercise-induced variation in lung volumes is an important source of ventilatory limitation and is linked to exercise intolerance in COPD. The aim of this study was to compare the correlations of walk distance and lung volumes measured before and after a 6-min walk test (6MWT) in subjects with COPD. Forty-five subjects with stable COPD (mean pre-bronchodilator FEV1: 47 ± 18% predicted) underwent a 6MWT. Body plethysmography was performed immediately pre- and post-6MWT. Correlations were generally stronger between 6-min walk distance and post-6MWT lung volumes than between 6-min walk distance and pre-6MWT lung volumes, except for FEV1. These differences in Pearson correlation coefficients were significant for residual volume expressed as percent of total lung capacity (-0.67 vs -0.58, P = .043), percent of predicted residual volume expressed as percent of total lung capacity (-0.68 vs -0.59, P = .026), inspiratory vital capacity (0.65 vs 0.54, P = .019), percent of predicted inspiratory vital capacity (0.49 vs 0.38, P = .037), and percent of predicted functional residual capacity (-0.62 vs -0.47, P = .023). In subjects with stable COPD, lung volumes measured immediately after 6MWT are more closely related to exercise limitation than baseline lung volumes measured before 6MWT, except for FEV1. Therefore, pulmonary function testing immediately after exercise should be included in future studies on COPD for the assessment of exercise-induced ventilatory constraints to physical performance that cannot be adequately assessed from baseline pulmonary function testing at rest. Copyright © 2014 by Daedalus Enterprises.

The 6-minute walk test in female fibromyalgia patients: relationship with tenderness, symptomatology, quality of life, and coping strategies.

PubMed

Carbonell-Baeza, Ana; Ruiz, Jonatan R; Aparicio, Virginia A; Ortega, Francisco B; Delgado-Fernández, Manuel

2013-12-01

The purpose of this study was to examine the relationship between the 6-minute walk test (6-MWT) and tenderness, symptomatology, quality of life, and coping strategies in women with fibromyalgia. One hundred eighteen women with fibromyalgia aged 51.9 ± 7.3 years participated in the study. The examination included the 6-MWT, tender points, and the following questionnaires: Fibromyalgia Impact Questionnaire (FIQ), Short-Form Health Survey 36 (SF-36), and Vanderbilt Pain Management Inventory. Fair correlations between the 6-MWT and the subscales of physical impairment (FIQ) and physical function (SF-36) were observed (ρ -0.365 and 0.347, respectively, both p < .001). The 6-MWT showed a weak relationship with tenderness (ρ 0.201 and -0.191 for algometer score and tender points count, respectively, both p < .05). The relationship between the 6-MWT and global score of FIQ, and FIQ subscales of pain and fatigue were weak (ρ -0.201, -0.211, and -0.226, respectively, all p < .05). The 6-MWT showed a weak relationship with bodily pain and vitality scales of SF-36 (ρ 0.256 and 0.258, respectively, both p = .005) and with passive and active coping strategies (ρ -0.255 and 0.223, both p < .05). This study in women with fibromyalgia shows significant relationships, ranging from weak to fair, between the 6-MWT and tenderness, symptomatology, quality of life, and coping strategies. These findings indicate that functional capacity, as assessed by the distance walked in 6 minutes, might be important when planning the assessment, treatment, and monitoring of patients with fibromyalgia. Copyright © 2013 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.

Are the Average Gait Speeds During the 10 Meter and 6 Minute Walk Tests Redundant in Parkinson Disease?

PubMed Central

Duncan, Ryan P.; Combs-Miller, Stephanie A.; McNeely, Marie E.; Leddy, Abigail L.; Cavanaugh, James T.; Dibble, Leland E.; Ellis, Terry D.; Ford, Matthew P.; Foreman, K. Bo; Earhart, Gammon M.

2016-01-01

We investigated the relationships between average gait speed collected with the 10 Meter Walk Test (Comfortable and Fast) and 6 Minute Walk Test (6MWT) in 346 people with Parkinson disease (PD) and how the relationships change with increasing disease severity. Pearson correlation and linear regression analyses determined relationships between 10 Meter Walk Test and 6MWT gait speed values for the entire sample and for sub-samples stratified by Hoehn & Yahr (H&Y) stage I (n=53), II (n=141), III (n=135) and IV (n=17). We hypothesized that redundant tests would be highly and significantly correlated (i.e. r > 0.70, p < 0.05) and would have a linear regression model slope of 1 and intercept of 0. For the entire sample, 6MWT gait speed was significantly (p<0.001) related to the Comfortable 10 Meter Walk Test (r=0.75) and Fast 10 Meter Walk Test (r=0.79) gait speed, with 56% and 62% of the variance in 6MWT gait speed explained, respectively. The regression model of 6MWT gait speed predicted by Comfortable 10 Meter Walk gait speed produced slope and intercept values near 1 and 0, respectively, especially for participants in H&Y stages II–IV. In contrast, slope and intercept values were further from 1 and 0, respectively, for the Fast 10 Meter Walk Test. Comfortable 10 Meter Walk Test and 6MWT gait speeds appeared to be redundant in people with moderate to severe PD, suggesting the Comfortable 10 Meter Walk Test can be used to estimate 6MWT distance in this population. PMID:27915221

Developmental assessment of the Fort St. Vrain version of the Composite HTGR Analysis Program (CHAP-2)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stroh, K.R.

1980-01-01

The Composite HTGR Analysis Program (CHAP) consists of a model-independent systems analysis mainframe named LASAN and model-dependent linked code modules, each representing a component, subsystem, or phenomenon of an HTGR plant. The Fort St. Vrain (FSV) version (CHAP-2) includes 21 coded modules that model the neutron kinetics and thermal response of the core; the thermal-hydraulics of the reactor primary coolant system, secondary steam supply system, and balance-of-plant; the actions of the control system and plant protection system; the response of the reactor building; and the relative hazard resulting from fuel particle failure. FSV steady-state and transient plant data are beingmore » used to partially verify the component modeling and dynamic smulation techniques used to predict plant response to postulated accident sequences.« less

Turbomachinery design considerations for the nuclear HTGR-GT power plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

McDonald, C.F.; Smith, M.J.

1979-11-01

For several years, design studies have been under way in the USA on a nuclear closed-cycle gas turbine plant (HTGR-GT). Design aspects of the helium turbomachine portion of these studies are presented. Gas dynamic and mechanical design considerations are presented for helium turbomachines in the 400-MW(e) (non-intercooled) and 600-MW(e) (intercooled) power range. Design of the turbomachine is a key element in the overall power plant program effort, which is currently directed toward the selection of a reference HTGR-GT commercial plant configuration for the US utility market. A conservative design approach has been emphasized to provide maximum safety and durability. Themore » studies presented for the integrated plant concept outline the necessary close working relationship between the reactor primary system and turbomachine designers.« less

Performance in the 6-minute walk test and postoperative pulmonary complications in pulmonary surgery: an observational study.

PubMed

Santos, Bruna F A; Souza, Hugo C D; Miranda, Aline P B; Cipriano, Federico G; Gastaldi, Ada C

2016-01-01

To assess functional capacity in the preoperative phase of pulmonary surgery by comparing predicted and obtained values for the six-minute walk test (6MWT) in patients with and without postoperative pulmonary complication (PPC) METHOD: Twenty-one patients in the preoperative phase of open thoracotomy were evaluated using the 6MWT, followed by monitoring of the postoperative evolution of each participant who underwent the routine treatment. Participants were then divided into two groups: the group with PPC and the group without PPC. The results were also compared with the predicted values using reference equations for the 6MWT RESULTS: Over half (57.14%) of patients developed PPC. The 6MWT was associated with the odds for PPC (odds ratio=22, p=0.01); the group without PPC in the postoperative period walked 422.38 (SD=72.18) meters during the 6MWT, while the group with PPC walked an average of 340.89 (SD=100.93) meters (p=0.02). The distance traveled by the group without PPC was 80% of the predicted value, whereas the group with PPC averaged less than 70% (p=0.03), with more appropriate predicted values for the reference equations The 6MWT is an easy, safe, and feasible test for routine preoperative evaluation in pulmonary surgery and may indicate patients with a higher chance of developing PPC.

Gas core reactors for actinide transmutation. [uranium hexafluoride

NASA Technical Reports Server (NTRS)

Clement, J. D.; Rust, J. H.; Wan, P. T.; Chow, S.

1979-01-01

The preliminary design of a uranium hexafluoride actinide transmutation reactor to convert long-lived actinide wastes to shorter-lived fission product wastes was analyzed. It is shown that externally moderated gas core reactors are ideal radiators. They provide an abundant supply of thermal neutrons and are insensitive to composition changes in the blanket. For the present reactor, an initial load of 6 metric tons of actinides is loaded. This is equivalent to the quantity produced by 300 LWR-years of operation. At the beginning, the core produces 2000 MWt while the blanket generates only 239 MWt. After four years of irradiation, the actinide mass is reduced to 3.9 metric tonnes. During this time, the blanket is becoming more fissile and its power rapidly approaches 1600 MWt. At the end of four years, continuous refueling of actinides is carried out and the actinide mass is held constant. Equilibrium is essentially achieved at the end of eight years. At equilibrium, the core is producing 1400 MWt and the blanket 1600 MWt. At this power level, the actinide destruction rate is equal to the production rate from 32 LWRs.

Microwave-based treatments of wheat kernels do not abolish gluten epitopes implicated in celiac disease.

PubMed

Gianfrani, Carmen; Mamone, Gianfranco; la Gatta, Barbara; Camarca, Alessandra; Di Stasio, Luigia; Maurano, Francesco; Picascia, Stefania; Capozzi, Vito; Perna, Giuseppe; Picariello, Gianluca; Di Luccia, Aldo

2017-03-01

Microwave based treatment (MWT) of wet wheat kernels induced a striking reduction of gluten, up to <20 ppm as determined by R5-antibodybased ELISA, so that wheat could be labeled as gluten-free. In contrast, analysis of gluten peptides by G12 antibody-based ELISA, mass spectrometry-based proteomics and in vitro assay with T cells of celiac subjects, indicated no difference of antigenicity before and after MWT. SDS-PAGE analysis and Raman spectroscopy demonstrated that MWT simply induced conformational modifications, reducing alcohol solubility of gliadins and altering the access of R5-antibody to the gluten epitopes. Thus, MWT neither destroys gluten nor modifies chemically the toxic epitopes, contradicting the preliminary claims that MWT of wheat kernels detoxifies gluten. This study provides evidence that R5-antibody ELISA alone is not effective to determine gluten in thermally treated wheat products. Gluten epitopes in processed wheat should be monitored using strategies based on combined immunoassays with T cells from celiacs, G12-antibody ELISA after proteolysis and proper molecular characterization. Copyright © 2017 Elsevier Ltd. All rights reserved.

Predicting home and community walking activity in people with stroke.

PubMed

Fulk, George D; Reynolds, Chelsea; Mondal, Sumona; Deutsch, Judith E

2010-10-01

To determine the ability of the 6-minute walk test (6MWT) and other commonly used clinical outcome measures to predict home and community walking activity in high-functioning people with stroke. Cross-sectional. Outpatient physical therapy clinic. Participants (N=32) with chronic stroke (n=19; >6mo poststroke) with self-selected gait speed (GS) faster than .40m/s and age-matched healthy participants (n=13). Not applicable. 6MWT, self-selected GS, Berg Balance Scale (BBS), lower extremity motor section of the Fugl-Meyer Assessment, and Stroke Impact Scale. Dependent variable: average steps taken per day during a 7-day period, measured using an accelerometer. 6MWT, self-selected GS, and BBS were moderately related to home and community walking activity. The 6MWT was the only predictor of average steps taken per day; it explained 46% of the variance in steps per day. The 6MWT is a useful outcome measure in higher functioning people with stroke to guide intervention and assess community walking activity. Copyright © 2010 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Assessment of the SRI Gasification Process for Syngas Generation with HTGR Integration -- White Paper

DOE Office of Scientific and Technical Information (OSTI.GOV)

A.M. Gandrik

2012-04-01

This white paper is intended to compare the technical and economic feasibility of syngas generation using the SRI gasification process coupled to several high-temperature gas-cooled reactors (HTGRs) with more traditional HTGR-integrated syngas generation techniques, including: (1) Gasification with high-temperature steam electrolysis (HTSE); (2) Steam methane reforming (SMR); and (3) Gasification with SMR with and without CO2 sequestration.

Comparison of the immediate efficacy of the Spinomed® back orthosis and posture training support on walking ability in elderly people with thoracic kyphosis.

PubMed

Namdar, Nategh; Arazpour, Mokhtar; Ahmadi Bani, Monireh

2017-12-21

The effect of spinal orthoses, including the Spinomed ® and posture training support (PTS) in improving balance and reducing falls in older people has been previously evaluated. However, there is little evidence available regarding their effect on the walking ability of older individuals with thoracic hyperkyphosis. This study was therefore designed to compare the immediate effect of the Spinomed ® orthosis and PTS on specific gait parameters in this patient group. A total of 34 older volunteer subjects with thoracic hyperkyphosis participated in this study and were randomly allocated into two groups, to either walk with the Spinomed ® orthosis in situ or the PTS. The elderly mobility scale test (EMS), two-minute walk test (2-MWT), and 10-meter walk test (10-MWT) were used to evaluate their walking performance, the distance walked and their walking speed respectively. There were no significant differences in the mean age, body mass index (BMI), kyphosis angle, EMS, 2-MWT, and 10-MWT between the groups at baseline. All parameters were uniform amongst the two groups. The Spinomed ® orthosis and PTS both had a positive and significant effect on the EMS score, the 2-MWT, and the 10-MWT. No significant difference was detected between two the types of orthoses in terms of the EMS score, the 2-MWT, or the 10-MWT. The Spinomed ® and PTS were both effective in improving all the primary outcome measures, with similar improvements demonstrated by both orthoses. Implications for rehabilitations In this category, one of the approaches to treat the elderly with hyperkyphosis is the use of spinal orthoses such as Spinomed ® orthosis and posture training support (PTS). The results showed that the anti-kyphosis orthosis including Spinomed ® and PTS played effective roles in the elderly with hyperkyphosis to improve their walking function. According to the current study results, there was no significant difference between the efficacies of these orthoses in the mentioned parameters.

The Shock and Vibration Digest. Volume 14, Number 11

DTIC Science & Technology

1982-11-01

cooled reactor 1981) ( HTGR ) core under seismic excitation his been developed . N82-18644 The computer program can be used to predict the behavior (In...French) of the HTGR core under seismic excitation. Key Words: Computer programs , Modal analysis, Beams, Undamped structures A computation method is...30) PROGRAMMING c c Dale and Cohen [221 extended the method of McMunn and Plunkett [201 developed a compute- McMunn and Plunkett to continuous systems

Novel algorithm for a smartphone-based 6-minute walk test application: algorithm, application development, and evaluation.

PubMed

Capela, Nicole A; Lemaire, Edward D; Baddour, Natalie

2015-02-20

The 6-minute walk test (6MWT: the maximum distance walked in 6 minutes) is used by rehabilitation professionals as a measure of exercise capacity. Today's smartphones contain hardware that can be used for wearable sensor applications and mobile data analysis. A smartphone application can run the 6MWT and provide typically unavailable biomechanical information about how the person moves during the test. A new algorithm for a calibration-free 6MWT smartphone application was developed that uses the test's inherent conditions and smartphone accelerometer-gyroscope data to report the total distance walked, step timing, gait symmetry, and walking changes over time. This information is not available with a standard 6MWT and could help with clinical decision-making. The 6MWT application was evaluated with 15 able-bodied participants. A BlackBerry Z10 smartphone was worn on a belt at the mid lower back. Audio from the phone instructed the person to start and stop walking. Digital video was independently recorded during the trial as a gold-standard comparator. The average difference between smartphone and gold standard foot strike timing was 0.014 ± 0.015 s. The total distance calculated by the application was within 1 m of the measured distance for all but one participant, which was more accurate than other smartphone-based studies. These results demonstrated that clinically relevant 6MWT results can be achieved with typical smartphone hardware and a novel algorithm.

Selection of Mother Wavelet Functions for Multi-Channel EEG Signal Analysis during a Working Memory Task

PubMed Central

Al-Qazzaz, Noor Kamal; Hamid Bin Mohd Ali, Sawal; Ahmad, Siti Anom; Islam, Mohd Shabiul; Escudero, Javier

2015-01-01

We performed a comparative study to select the efficient mother wavelet (MWT) basis functions that optimally represent the signal characteristics of the electrical activity of the human brain during a working memory (WM) task recorded through electro-encephalography (EEG). Nineteen EEG electrodes were placed on the scalp following the 10–20 system. These electrodes were then grouped into five recording regions corresponding to the scalp area of the cerebral cortex. Sixty-second WM task data were recorded from ten control subjects. Forty-five MWT basis functions from orthogonal families were investigated. These functions included Daubechies (db1–db20), Symlets (sym1–sym20), and Coiflets (coif1–coif5). Using ANOVA, we determined the MWT basis functions with the most significant differences in the ability of the five scalp regions to maximize their cross-correlation with the EEG signals. The best results were obtained using “sym9” across the five scalp regions. Therefore, the most compatible MWT with the EEG signals should be selected to achieve wavelet denoising, decomposition, reconstruction, and sub-band feature extraction. This study provides a reference of the selection of efficient MWT basis functions. PMID:26593918

Analysis of the performance of women with fibromyalgia in the six-minute walk test and its relation with health and quality of life.

PubMed

Latorre-Román, P; Santos-Campos, M; Heredia-Jimenez, J; Delgado-Fernández, M; Soto-Hermoso, V

2014-08-01

Fibromyalgia (FM) is a chronic syndrome characterized by widespread musculoskeletal pain that causes a significant reduction in functional capacity, affecting thus health and quality of life (QOL). The aim of the present study was to evaluate the performance of FM patients in the 6-Minute Walk Test (6MWT) and its relation with health and QOL. Thirty-six FM patients (all women), differentiated by degree of severity of disease, and 14 healthy women were evaluated. Distance walked in the 6MWT, cardiorespiratory responses, heart rate responses, kinematic parameters of gait, the results of the Fibromyalgia Impact Questionnaire (FIQ), and the results of the Short-Form Healthy Survey (SF-36) were analyzed. Women with FM covered a shorter distance in the 6MWT, had a lower cardiorespiratory response, and had lower spatio-temporal parameters of gait than healthy women. No correlation was found in FM patients between the total FIQ score and the distance walked in the 6MWT. The analysis of performance parameters in the 6MWT may be an element of clinical relevance in FM patients.

Selection of Mother Wavelet Functions for Multi-Channel EEG Signal Analysis during a Working Memory Task.

PubMed

Al-Qazzaz, Noor Kamal; Bin Mohd Ali, Sawal Hamid; Ahmad, Siti Anom; Islam, Mohd Shabiul; Escudero, Javier

2015-11-17

We performed a comparative study to select the efficient mother wavelet (MWT) basis functions that optimally represent the signal characteristics of the electrical activity of the human brain during a working memory (WM) task recorded through electro-encephalography (EEG). Nineteen EEG electrodes were placed on the scalp following the 10-20 system. These electrodes were then grouped into five recording regions corresponding to the scalp area of the cerebral cortex. Sixty-second WM task data were recorded from ten control subjects. Forty-five MWT basis functions from orthogonal families were investigated. These functions included Daubechies (db1-db20), Symlets (sym1-sym20), and Coiflets (coif1-coif5). Using ANOVA, we determined the MWT basis functions with the most significant differences in the ability of the five scalp regions to maximize their cross-correlation with the EEG signals. The best results were obtained using "sym9" across the five scalp regions. Therefore, the most compatible MWT with the EEG signals should be selected to achieve wavelet denoising, decomposition, reconstruction, and sub-band feature extraction. This study provides a reference of the selection of efficient MWT basis functions.

Improvement of Modeling HTGR Neutron Physics by Uncertainty Analysis with the Use of Cross-Section Covariance Information

NASA Astrophysics Data System (ADS)

Boyarinov, V. F.; Grol, A. V.; Fomichenko, P. A.; Ternovykh, M. Yu

2017-01-01

This work is aimed at improvement of HTGR neutron physics design calculations by application of uncertainty analysis with the use of cross-section covariance information. Methodology and codes for preparation of multigroup libraries of covariance information for individual isotopes from the basic 44-group library of SCALE-6 code system were developed. A 69-group library of covariance information in a special format for main isotopes and elements typical for high temperature gas cooled reactors (HTGR) was generated. This library can be used for estimation of uncertainties, associated with nuclear data, in analysis of HTGR neutron physics with design codes. As an example, calculations of one-group cross-section uncertainties for fission and capture reactions for main isotopes of the MHTGR-350 benchmark, as well as uncertainties of the multiplication factor (k∞) for the MHTGR-350 fuel compact cell model and fuel block model were performed. These uncertainties were estimated by the developed technology with the use of WIMS-D code and modules of SCALE-6 code system, namely, by TSUNAMI, KENO-VI and SAMS. Eight most important reactions on isotopes for MHTGR-350 benchmark were identified, namely: 10B(capt), 238U(n,γ), ν5, 235U(n,γ), 238U(el), natC(el), 235U(fiss)-235U(n,γ), 235U(fiss).

Six-minute stepper test: a valid clinical exercise tolerance test for COPD patients

PubMed Central

Grosbois, JM; Riquier, C; Chehere, B; Coquart, J; Béhal, H; Bart, F; Wallaert, B; Chenivesse, C

2016-01-01

Introduction Exercise tolerance testing is an integral part of the pulmonary rehabilitation (PR) management of patients with chronic obstructive pulmonary disease (COPD). The 6-minute stepper test (6MST) is a new, well-tolerated, reproducible exercise test, which can be performed without any spatial constraints. Objective The aim of this study was to compare the results of the 6MST to those obtained during a 6-minute walk test (6MWT) and cardiopulmonary exercise testing (CPET) in a cohort of COPD patients. Methods Ninety-one COPD patients managed by outpatient PR and assessed by 6MST, 6MWT, and CPET were retrospectively included in this study. Correlations between the number of steps on the 6MST, the distance covered on the 6MWT, oxygen consumption, and power at the ventilatory threshold and at maximum effort during CPET were analyzed before starting PR, and the improvement on the 6MST and 6MWT was compared after PR. Results The number of steps on the 6MST was significantly correlated with the distance covered on the 6MWT (r=0.56; P<0.0001), the power at maximum effort (r=0.46; P<0.0001), and oxygen consumption at maximum effort (r=0.39; P<0.005). Performances on the 6MST and 6MWT were significantly improved after PR (570 vs 488 steps, P=0.001 and 448 vs 406 m, respectively; P<0.0001). Improvements of the 6MST and 6MWT after PR were significantly correlated (r=0.34; P=0.03). Conclusion The results of this study show that the 6MST is a valid test to evaluate exercise tolerance in COPD patients. The use of this test in clinical practice appears to be particularly relevant for the assessment of patients managed by home PR. PMID:27099483

Effect of body weight loss on cardiopulmonary function assessed by 6-minute walk test and arterial blood gas analysis in obese dogs.

PubMed

Manens, J; Ricci, R; Damoiseaux, C; Gault, S; Contiero, B; Diez, M; Clercx, C

2014-01-01

Few studies show the detrimental effect of canine obesity on cardiopulmonary function (CPF). The 6-Minute Walk Test (6MWT) is a noninvasive exercise test easy to perform in clinical settings. The aim of this study was to investigate the effect of obesity and body weight loss (BWL) on CPF assessed by the 6MWT and arterial blood gas analysis. Six experimental Beagles and 9 privately owned obese dogs were enrolled in a diet-induced BWL program. Arterial blood gas analysis and 6MWT were repeated in obese subjects (BCS 8-9/9), in the middle of BWL (overweight, BCS 6-7/9), and in lean dogs (BCS 5/9). Heart rate (HRp) and oxygen saturation (SpO2 ) were measured by pulse oximetry before the 6MWT, at midtest, and during a 5-minute recovery period. Twelve dogs completed the BWL program (initial BW, 27.3 ± 2.9 kg; final BW, 20.85 ± 2.9, lsmeans ± SE, P ≤ .001). BWL caused a significant increase in 6MWT walked distance (WD; obese: 509 ± 35 m; overweight: 575 ± 36 m; lean: 589 ± 36 m; P ≤ .05). Resting arterial blood gas results were not influenced by BWL. Including all time points, obese dogs showed higher HRp and lower SpO2 compared to overweight and lean dogs. SpO2 at the end of the walk was significantly lower in obese dogs. Obesity negatively affects 6MWT performances in dogs. The 6MWT may be used to demonstrate the efficacy of BWL to improve CPF and quality of life in obese dogs. Although BWL induced significant improvement of cardiopulmonary parameters before ideal BW, WD improved until the end of the BWL program. Copyright © 2013 by the American College of Veterinary Internal Medicine.

Validity of the 6 min walk test in prediction of the anaerobic threshold before major non-cardiac surgery.

PubMed

Sinclair, R C F; Batterham, A M; Davies, S; Cawthorn, L; Danjoux, G R

2012-01-01

For perioperative risk stratification, a robust, practical test could be used where cardiopulmonary exercise testing (CPET) is unavailable. The aim of this study was to assess the utility of the 6 min walk test (6MWT) distance to discriminate between low and high anaerobic threshold (AT) in patients awaiting major non-cardiac surgery. In 110 participants, we obtained oxygen consumption at the AT from CPET and recorded the distance walked (in m) during a 6MWT. Receiver operating characteristic (ROC) curve analysis was used to derive two different cut-points for 6MWT distance in predicting an AT of <11 ml O(2) kg(-1) min(-1); one using the highest sum of sensitivity and specificity (conventional method) and the other adopting a 2:1 weighting in favour of sensitivity. In addition, using a novel linear regression-based technique, we obtained lower and upper cut-points for 6MWT distance that are predictive of an AT that is likely to be (P≥0.75) <11 or >11 ml O(2) kg(-1) min(-1). The ROC curve analysis revealed an area under the curve of 0.85 (95% confidence interval, 0.77-0.91). The optimum cut-points were <440 m (conventional method) and <502 m (sensitivity-weighted approach). The regression-based lower and upper 6MWT distance cut-points were <427 and >563 m, respectively. Patients walking >563 m in the 6MWT do not routinely require CPET; those walking <427 m should be referred for further evaluation. In situations of 'clinical uncertainty' (≥427 but ≤563 m), the number of clinical risk factors and magnitude of surgery should be incorporated into the decision-making process. The 6MWT is a useful clinical tool to screen and risk stratify patients in departments where CPET is unavailable.

Overview of the Westinghouse Small Modular Reactor building layout

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cronje, J. M.; Van Wyk, J. J.; Memmott, M. J.

The Westinghouse Small Modular Reactor (SMR) is an 800 MWt (>225 MWe) integral pressurized water reactor (iPWR), in which all of the components typically associated with the nuclear steam supply system (NSSS) of a nuclear power plant are incorporated within a single reactor pressure vessel. This paper is the third in a series of four papers, which describe the design and functionality of the Westinghouse SMR. It focuses in particular upon the plant building layout and modular design of the Westinghouse SMR. In the development of small modular reactors, the building layout is an area where the safety of themore » plant can be improved by applying new design approaches. This paper will present an overview of the Westinghouse SMR building layout and indicate how the design features improve the safety and robustness of the plant. The Westinghouse SMR is designed with no shared systems between individual reactor units. The main buildings inside the security fence are the nuclear island, the rad-waste building, the annex building, and the turbine building. All safety related equipment is located in the nuclear island, which is a seismic class 1 building. To further enhance the safety and robustness of the design, the reactor, containment, and most of the safety related equipment are located below grade on the nuclear island. This reduces the possibility of severe damage from external threats or natural disasters. Two safety related ultimate heat sink (UHS) water tanks that are used for decay heat removal are located above grade, but are redundant and physically separated as far as possible for improved safety. The reactor and containment vessel are located below grade in the center of the nuclear island. The rad-waste and other radioactive systems are located on the bottom floors to limit the radiation exposure to personnel. The Westinghouse SMR safety trains are completely separated into four unconnected quadrants of the building, with access between quadrants only allowed above grade. This is an improvement to conventional reactor design since it prevents failures of multiple trains during floods or fires and other external events. The main control room is located below grade, with a remote shutdown room in a different quadrant. All defense in depth systems are placed on the nuclear island, primarily above grade, while the safety systems are located on lower floors. The economics of the Westinghouse SMR challenges the established approach of large Light Water Reactors (LWR) that utilized the economies of scale to reach economic competitiveness. To serve the market expectation of smaller capital investment and cost competitive energy, a modular design approach is implemented within the Westinghouse SMR. The Westinghouse SMR building layout integrates the three basic design constraints of modularization; transportation, handling and module-joining technology. (authors)« less

[Effect of a surgical mask on six minute walking distance].

PubMed

Person, E; Lemercier, C; Royer, A; Reychler, G

2018-03-01

Six minutes walking test (6MWT) is regularly used in pulmonology. To minimize the risk of cross-infection, some patients must wear surgical mask at rest and sometimes during exercise. To evaluate the effect of wearing a surgical mask during 6MWT in healthy subjects. It is a prospective study on 44 healthy subjects. After a first 6MWT for training, they performed randomly two 6MWT: with or without a surgical mask. Distance and dyspnea, heart rate and saturation variations were recorded. Distance was not modified by the mask (P=0.99). Dyspnea variation was significantly higher with surgical mask (+5.6 vs. +4.6; P<0.001) and the difference was clinically relevant. No difference was found for the variation of other parameters. Wearing a surgical mask modifies significantly and clinically dyspnea without influencing walked distance. Copyright © 2017 SPLF. Published by Elsevier Masson SAS. All rights reserved.

Prescribing Aerobic Exercise Intensity without a Cardiopulmonary Exercise Test Post Stroke: Utility of the Six-Minute Walk Test.

PubMed

Marzolini, Susan; Oh, Paul; Corbett, Dale; Dooks, Daryl; Calouro, Marcella; MacIntosh, Bradley J; Goodman, Rachel; Brooks, Dina

2016-09-01

The cardiopulmonary exercise test (CPET) is an established method for determining target exercise training intensity (ventilatory threshold [VAT]) and cardiovascular risk; unfortunately, CPET is not readily accessible to people post stroke. The objective of this study was to determine the utility of the 6-minute walk test (6MWT) as a less resource-intensive alternative to CPET for prescribing exercise intensity to people post stroke with motor impairments. Sixty participants (male, 71.7%; 13.5 ± 22.5 [mean ± standard deviation] months post stroke; age 64.5 ± 12.5 years, with a Chedoke-McMaster Stroke Assessment score of 4.9 ± .9 of the leg) underwent 6MWT, CPET, balance, strength, and cognition assessments. 6MWT heart rate (hr) was significantly lower than VAT-hr (92.3 ± 14.8 beats⋅min(-1) versus 99.8 ± 15.7 beats⋅min(-1), respectively, P < .001; correlation r = .7, P < .001). Bland-Altman analysis revealed that the 6MWT underestimated the VAT-hr by 7.7 ± 11.5%. The 95% confidence interval of the mean bias was large (14.8% and -30.3%), reflecting poor agreement, with 71.7% (n = 43) of the participants unable to reach a walking intensity at or above the VAT-hr. Lower oxygen uptake at the VAT (β = .655, P = .004), higher 6MWT-hr (β = 1.07, P = .01), and better balance (β = 1.128, P = .04) were associated with greater utility of the 6MWT for prescribing exercise. The 6MWT-hr was not interchangeable with the target training VAT-hr determined by CPET. However, in combination with CPET, the 6MWT will indicate when deficits preclude walking alone as the primary exercise modality for optimizing cardiovascular fitness. Future studies to develop a less resource-intensive, multimodal alternative to the CPET for prescribing exercise are needed. A modality that minimizes the effect of stroke deficits, specifically poor balance, should be included. Copyright © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Cardiorespiratory adaptation in a 6-minute walk test by fibrotic idiopathic interstitial pneumonia patients who did or did not respond to pulmonary rehabilitation.

PubMed

Chéhère, Baptiste; Bougault, Valérie; Chenivesse, Cécile; Grosbois, Jean-Marie; Wallaert, Benoit

2018-06-14

Pulmonary rehabilitation (PR) improves performance in the 6-min walk test (6MWT) in a subset of patients with fibrotic idiopathic interstitial pneumonia (f-IIP); however, a large proportion of patients do not respond to PR. To investigate the effects of a PR program on cardiorespiratory responses during a 6MWT and to identify the characteristics of patients who do not show improved performance after PR. An observational study. Patients were recruited from the Competence Centre for Rare Pulmonary Diseases at Lille University Hospital, France and completed an 8-week home-based PR program. A total of 19 patients with f-IIP; 12 with idiopathic pulmonary fibrosis (IPF) and 7 with fibrotic non-specific interstitial pneumonia. Patients underwent spirometry and completed a 6MWT before and after an 8- week PR program. Gas exchange, heart rate, and pulse O2 saturation were measured continuously during the 6MWT. Quality of life, dyspnoea, and anxiety/depression were assessed using the Short-Form 36 (SF-36), the baseline/transition dyspnoea index (BDI/TDI), and the Hospital Anxiety and Depression Scale (HADS) questionnaires. Patients who did and did not improve the distance walked in the 6MWT by at least 30 m after PR were classified as responders (n=9) and non-responders (n=10), respectively. O2 uptake, ventilation rate, and distance covered during the 6MWT were significantly improved only in the responder group (p<0.05). Changes in SF-36, BDI/TDI, and HADS scores did not differ significantly between responders and non-responders. The non-responder group contained significantly more patients with IPF (p<0.05) and experienced greater arterial oxygen desaturation during the 6MWT compared with the responder group. Failure to improve performance in the 6MWT after PR was associated with a diagnosis of IPF, non-improvement in gas exchange, and greater arterial oxygen desaturation. Most f-IIP patients who did not respond to PR were diagnosed with IPF and displayed greater hypoxemia during exercise. Clinical practitioners should seek to determine why patients fail to improve exercise performance after PR and propose an alternative exercise regimen to these patients.

An Overview of Reactor Concepts, a Survey of Reactor Designs.

DTIC Science & Technology

1985-02-01

may be very different. HTGRs may use highly enriched uranium, thereby yielding better fuel economy and a reduc- tion of the actual core size for a...specific power level. The HTGR core may have fuel and control rods placed in graphite arrays similar to PWR core con- figuration, or they may have fuel ...rods are pulled out. A Peach Bottom core design is another HTGR design. This design is featured by the fuel pin’s ability to purge itself of fission

Uncertainty and Sensitivity Analyses of a Pebble Bed HTGR Loss of Cooling Event

DOE PAGES

Strydom, Gerhard

2013-01-01

The Very High Temperature Reactor Methods Development group at the Idaho National Laboratory identified the need for a defensible and systematic uncertainty and sensitivity approach in 2009. This paper summarizes the results of an uncertainty and sensitivity quantification investigation performed with the SUSA code, utilizing the International Atomic Energy Agency CRP 5 Pebble Bed Modular Reactor benchmark and the INL code suite PEBBED-THERMIX. Eight model input parameters were selected for inclusion in this study, and after the input parameters variations and probability density functions were specified, a total of 800 steady state and depressurized loss of forced cooling (DLOFC) transientmore » PEBBED-THERMIX calculations were performed. The six data sets were statistically analyzed to determine the 5% and 95% DLOFC peak fuel temperature tolerance intervals with 95% confidence levels. It was found that the uncertainties in the decay heat and graphite thermal conductivities were the most significant contributors to the propagated DLOFC peak fuel temperature uncertainty. No significant differences were observed between the results of Simple Random Sampling (SRS) or Latin Hypercube Sampling (LHS) data sets, and use of uniform or normal input parameter distributions also did not lead to any significant differences between these data sets.« less

Associating Physical Activity Levels with Motor Performance and Physical Function in Childhood Survivors of Acute Lymphoblastic Leukemia.

PubMed

Hung, Stanley H; Rankin, Anne; Virji-Babul, Naznin; Pritchard, Sheila; Fryer, Christopher; Campbell, Kristin L

2017-01-01

Purpose: This cross-sectional, observational study investigated whether physical activity (PA) levels are associated with motor performance and physical function in children after treatment for acute lymphoblastic leukemia (ALL). Method: Participants aged 8-13 years who had completed treatment for ALL (3-36 months post-treatment) were tested at their oncology long-term follow-up appointment at the British Columbia Children's Hospital. PA level was measured using the Physical Activity Questionnaire for Older Children (PAQ-C). Motor performance was measured using the Bruininks-Oseretsky Test of Motor Proficiency, Second Edition, Short Form (BOT-2 SF), and physical function was measured using the 6-minute walk test (6MWT). Results: Thirteen children completed testing. PAQ-C scores were not associated with BOT-2 SF or 6MWT performance. Eleven children (85%) performed below the norm for the 6MWT. Children with elevated body mass index had poorer 6MWT but similar PAQ-C scores. Conclusion: PA was not found to be associated with motor performance and physical function. Participants who were overweight or obese had poorer 6MWT performance, which may indicate the need for closer monitoring of post-treatment weight status and physical function in the oncology follow-up setting.

Associating Physical Activity Levels with Motor Performance and Physical Function in Childhood Survivors of Acute Lymphoblastic Leukemia

PubMed Central

Hung, Stanley H.; Rankin, Anne; Virji-Babul, Naznin; Pritchard, Sheila; Fryer, Christopher

2017-01-01

Purpose: This cross-sectional, observational study investigated whether physical activity (PA) levels are associated with motor performance and physical function in children after treatment for acute lymphoblastic leukemia (ALL). Method: Participants aged 8–13 years who had completed treatment for ALL (3–36 months post-treatment) were tested at their oncology long-term follow-up appointment at the British Columbia Children's Hospital. PA level was measured using the Physical Activity Questionnaire for Older Children (PAQ-C). Motor performance was measured using the Bruininks-Oseretsky Test of Motor Proficiency, Second Edition, Short Form (BOT-2 SF), and physical function was measured using the 6-minute walk test (6MWT). Results: Thirteen children completed testing. PAQ-C scores were not associated with BOT-2 SF or 6MWT performance. Eleven children (85%) performed below the norm for the 6MWT. Children with elevated body mass index had poorer 6MWT but similar PAQ-C scores. Conclusion: PA was not found to be associated with motor performance and physical function. Participants who were overweight or obese had poorer 6MWT performance, which may indicate the need for closer monitoring of post-treatment weight status and physical function in the oncology follow-up setting. PMID:28154445

Sacubitril/Valsartan: Effect on Walking Test and Physical Capability.

PubMed

Sgorbini, Luca; Rossetti, Antonella; Galati, Alfonso

The 6-min walk test (6MWT) is a simple and inexpensive exercise test to evaluate physical functional capacity that is widely used in heart failure (HF) patients. With the 6MWT, a distance <350 m is associated with increased mortality in patients with HF, and change in walking distance >50 m is considered clinically relevant. To our knowledge, information on improvement in physical functional capacity with sacubitril/valsartan, as assessed by the 6MWT, is still scant. In our daily practice, we apply this test to all patients whenever possible; therefore, we report here the findings observed in a small series of 5 patients with HF with reduced ejection fraction after a 1-month treatment with sacubitril/valsartan at full dose. The mean distance walked on the 6MWT at baseline was 129 m (±64 SD), and this value increased to 436 m (±156) after 1 month of therapy with sacubitril/valsartan 97/103 mg b.i.d. The mean difference from baseline was 305 m (±110). According to these preliminary findings, in clinical practice, a 1-month therapy of sacubitril/valsartan optimized at a 97/103-mg b.i.d. dose appears to be associated with a relevant improvement in the 6MWT. © 2017 S. Karger AG, Basel.

Master Logic Diagram: An Approach to Identify Initiating Events of HTGRs

NASA Astrophysics Data System (ADS)

Purba, J. H.

2018-02-01

Initiating events of a nuclear power plant being evaluated need to be firstly identified prior to applying probabilistic safety assessment on that plant. Various types of master logic diagrams (MLDs) have been proposedforsearching initiating events of the next generation of nuclear power plants, which have limited data and operating experiences. Those MLDs are different in the number of steps or levels and different in the basis for developing them. This study proposed another type of MLD approach to find high temperature gas cooled reactor (HTGR) initiating events. It consists of five functional steps starting from the top event representing the final objective of the safety functions to the basic event representing the goal of the MLD development, which is an initiating event. The application of the proposed approach to search for two HTGR initiating events, i.e. power turbine generator trip and loss of offsite power, is provided. The results confirmed that the proposed MLD is feasiblefor finding HTGR initiating events.

Determining the minimum required uranium carbide content for HTGR UCO fuel kernels

DOE PAGES

McMurray, Jacob W.; Lindemer, Terrence B.; Brown, Nicholas R.; ...

2017-03-10

There are three important failure mechanisms that must be controlled in high-temperature gas-cooled reactor (HTGR) fuel for certain higher burnup applications are SiC layer rupture, SiC corrosion by CO, and coating compromise from kernel migration. All are related to high CO pressures stemming from free O generated when uranium present as UO 2 fissions and the O is not subsequently bound by other elements. Furthermore, in the HTGR UCO kernel design, CO buildup from excess O is controlled by the inclusion of additional uranium in the form of a carbide, UC x. An approach for determining the minimum UC xmore » content to ensure negligible CO formation was developed and demonstrated using CALPHAD models and the Serpent 2 reactor physics and depletion analysis tool. Our results are intended to be more accurate than previous estimates by including more nuclear and chemical factors, in particular the effect of transmutation products on the oxygen distribution as the fuel kernel composition evolves with burnup.« less

PHISICS/RELAP5-3D RESULTS FOR EXERCISES II-1 AND II-2 OF THE OECD/NEA MHTGR-350 BENCHMARK

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strydom, Gerhard

2016-03-01

The Idaho National Laboratory (INL) Advanced Reactor Technologies (ART) High-Temperature Gas-Cooled Reactor (HTGR) Methods group currently leads the Modular High-Temperature Gas-Cooled Reactor (MHTGR) 350 benchmark. The benchmark consists of a set of lattice-depletion, steady-state, and transient problems that can be used by HTGR simulation groups to assess the performance of their code suites. The paper summarizes the results obtained for the first two transient exercises defined for Phase II of the benchmark. The Parallel and Highly Innovative Simulation for INL Code System (PHISICS), coupled with the INL system code RELAP5-3D, was used to generate the results for the Depressurized Conductionmore » Cooldown (DCC) (exercise II-1a) and Pressurized Conduction Cooldown (PCC) (exercise II-2) transients. These exercises require the time-dependent simulation of coupled neutronics and thermal-hydraulics phenomena, and utilize the steady-state solution previously obtained for exercise I-3 of Phase I. This paper also includes a comparison of the benchmark results obtained with a traditional system code “ring” model against a more detailed “block” model that include kinetics feedback on an individual block level and thermal feedbacks on a triangular sub-mesh. The higher spatial fidelity that can be obtained by the block model is illustrated with comparisons of the maximum fuel temperatures, especially in the case of natural convection conditions that dominate the DCC and PCC events. Differences up to 125 K (or 10%) were observed between the ring and block model predictions of the DCC transient, mostly due to the block model’s capability of tracking individual block decay powers and more detailed helium flow distributions. In general, the block model only required DCC and PCC calculation times twice as long as the ring models, and it therefore seems that the additional development and calculation time required for the block model could be worth the gain that can be obtained in the spatial resolution« less

Development of a coolant channel helium and nitrogen gas ratio sensor for a high temperature gas reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cadell, S. R.; Woods, B. G.

2012-07-01

To measure the changing gas composition of the coolant during a postulated High Temperature Gas Reactor (HTGR) accident, an instrument is needed. This instrument must be compact enough to measure the ratio of the coolant versus the break gas in an individual coolant channel. This instrument must minimally impact the fluid flow and provide for non-direct signal routing to allow minimal disturbance to adjacent channels. The instrument must have a flexible geometry to allow for the measurement of larger volumes such as in the upper or lower plenum of a HTGR. The instrument must be capable of accurately functioning throughmore » the full operating temperature and pressure of a HTGR. This instrument is not commercially available, but a literature survey has shown that building off of the present work on Capacitance Sensors and Cross-Capacitors will provide a basis for the development of the desired instrument. One difficulty in developing and instrument to operate at HTGR temperatures is acquiring an electrical conductor that will not melt at 1600 deg. C. This requirement limits the material selection to high temperature ceramics, graphite, and exotic metals. An additional concern for the instrument is properly accounting for the thermal expansion of both the sensing components and the gas being measured. This work covers the basic instrument overview with a thorough discussion of the associated uncertainty in making these measurements. (authors)« less

Reliability, agreement, and responsiveness of a 6-minute walk/run test in patients with heart disease.

PubMed

Berghmans, Danielle D; Lenssen, Antoine F; Bastiaenen, Carolien H; Ilhan, Mustafa; Lencer, Nicole H; Roox, George M

2013-02-01

The 6-minute walk test (6 MWT) is widely used to assess exercise tolerance in cardiac rehabilitation (CR). However, previous research shows it to be insufficiently responsive, especially for patients with a relatively high maximal exercise tolerance at baseline. We therefore designed a 6-minute walk/run test (6 MWRT), which has the same duration as the 6 MWT but allows running. The objective of this study was to determine the test-retest reproducibility and responsiveness of this 6 MWRT. Responsiveness was investigated in a prospective cohort study among a group of patients entering CR at Maastricht University Medical Center, with a cross-sectional part to assess the test-retest reproducibility. Test-retest reproducibility (reliability and agreement) was investigated using the intraclass correlation (ICC) and a Bland-Altman plot of two measurements implemented in the first week of rehabilitation. Responsiveness of the 6 MWT and the 6 MWRT was calculated using the standard response mean (SRM) over a 6-week period. The first reproducibility analysis included 34 patients, the second 22 patients. The ICCs were 0.935 and 0.906, respectively, with limits of agreement of ± 79 and ± 61 m. The responsiveness analysis included 27 patients. The SRM values were 0.83 for the 6 MWT and 0.71 for the 6 MWRT. Although the 6 MWRT is a reproducible test in CR, its responsiveness is not superior to that of the 6 MWT. We therefore prefer the conventional 6 MWT as an evaluative measurement in CR and advise against using the 6 MWRT as (evaluative) measurement in CR for this purpose.

Cardio-respiratory responses of the 6-minute walk test in patients with refractory heart failure during the preoperative period for heart transplant surgery.

PubMed

Gerson, Cipriano; Bernardelli, Graziella França; Arena, Ross; Oliveira, Luis Vicente Franco; Valdez, Francisco; Branco, João Nelson Rodrigues

2010-06-01

The six-minute walk test (6MWT) has been used to assess functional capacity, clinical status and prognosis. There are a very few descriptions in the literature on the safety and metabolic impact of the test, especially in patients with severe heart failure, awaiting cardiac transplantation. The aim of the present study was to assess the cardiovascular responses and correlate the performance on the 6MWT with clinical status. From 15 initial candidates, twelve patients (10 males) aged 52 +/- 8 years were submitted to a comprehensive clinical evaluation. The patients performed the 6MWT with electrocardiographic and perceived exertion monitoring in addition to determination of blood lactate concentration. Patients were followed up for 12 months. The patients walked 399.4 +/- 122.5 meters, reaching a perceived exertion (PE) of 14.3 +/- 1.5 and an increase of 34% in resting heart rate. Two patients exhibited a greater severity of arrhythmia prior to the 6MWT, which did not increase during exertion. Four patients exhibited a significant increase in blood lactate levels (>5 mmol/dL) and three interrupted the test prematurely. The distance walked (D) revealed a correlation with the ejection fraction (%) and functional classification (NYHA). After 12 months of follow up, three patients died and seven were re-hospitalized due to heart failure decompensation. Clinical and electrocardiographic behavior suggests that the 6MWT is safe, but may be considered of high intensity for some patients with severe heart failure. Variables related to the performance on the 6MWT may be associated to worsening clinical status in this population.

Utility of a patient-reported outcome in measuring functional impairment during autologous stem cell transplant in patients with multiple myeloma.

PubMed

Shah, Nina; Shi, Qiuling; Giralt, Sergio; Williams, Loretta; Bashir, Qaiser; Qazilbash, Muzaffar; Champlin, Richard E; Cleeland, Charles S; Wang, Xin Shelley

2018-04-01

We aimed to determine the utility of a patient-reported outcome (PRO) as it relates to patient performed testing (PPT) for measuring functional status in multiple myeloma patients after autologous hematopoietic stem cell transplantation (auto-HCT). Symptom interference on walking (a PRO) was measured by the MD Anderson Symptom Inventory (MDASI). PPT was assessed via 6-min walk test (6MWT). Mixed effects modeling was used to examine (1) the longitudinal relationship between the MDASI score and 6MWT distance and (2) the MDASI scores between patients who did or did not complete the 6WMT. Receiver operating characteristic (ROC) curve analysis was performed to quantify the construct validity of the PRO by differentiating performance status. Seventy-nine patients were included. Mean 6MWT distance significantly correlated with MDASI-walking interference score (PRO) over the first month of auto-HCT (est = 6.09, p = 0.006). There was a significantly higher completion rate for MDASI versus 6MWT at each time point (p < 0.01). Patients who completed the 6MWT reported less interference on walking during the study period (est = 1.61, p < 0.0001). Finally, the PRO demonstrated significant construct validity for measuring functioning status with MDASI-walking against ECOG-PS as the anchor (AUC = 0.77, 95% CI 0.60-0.94, p = 0.003). The PRO of MDASI-walking interference is a valid physical functioning measure, correlating with an objective functional measure (6MWT) in MM patients undergoing auto-HCT. As patients with poorer functional status during therapy are less likely to complete PPT, this PRO may offer a more practical quantitative measure of functioning in patients.

Calf Muscle Oxygen Saturation During Six-Minute Walk Test And Its Relationship With Walking Impairment In Symptomatic Peripheral Artery Disease.

PubMed

Andrade-Lima, Aluísio; Cucato, Gabriel G; Domingues, Wagner J R; Germano-Soares, Antônio H; Cavalcante, Bruno R; Correia, Marilia A; Saes, Glauco F; Wolosker, Nelson; Gardner, Andrew W; Zerati, Antônio E; Ritti-Dias, Raphael M

2018-05-21

Impaired microcirculation is associated with poor walking capacity in symptomatic peripheral artery disease (PAD) patients during treadmill test, however, this test does not simulate the efforts of daily walking of these patients. Thus, the aim of the study was to describe the microcirculation responses during six-minute walk test (6MWT) and to analyze the relationship between microcirculation indicators and walking impairment in symptomatic PAD patients. Thirty-four patients were included (mean age = 67.6 ± 11.2). The clinical characteristics were collected and they performed a 6MWT in which initial claudication distance (ICD) and total walking distance (TWD) were recorded. During and after the 6MWT, calf muscle oxygen saturation (StO 2 ) parameters were monitored continuously to measure microcirculation behavior. The association between calf muscle StO 2 parameters and walking impairment was analyzed by Pearson or Spearman correlations. Walking impairment was not associated with any StO 2 parameters during exercise. In contrast, after 6MWT, recovery time of StO 2 (r = -0.472, P = .008) and recovery time to maximal StO 2 (r= -0.402, P = .019) were negatively correlated with ICD. Furthermore, the distance walked under claudication symptoms (ΔTWD - ICD) was positively correlated with recovery time to maximal StO 2 (r = 0.347, P = .048). In symptomatic PAD patients, shorter ICD values during a 6MWT are associated with a delayed recovery in calf muscle StO 2 after exercise. Calf muscle StO 2 parameters decrease subtly during 6MWT, suggesting that the degree of ischemia in the calf muscle during ground walking, simulating efforts of the daily walking, is relatively low. Copyright © 2018 Elsevier Inc. All rights reserved.

Material Control and Accounting Design Considerations for High-Temperature Gas Reactors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trond Bjornard; John Hockert

The subject of this report is domestic safeguards and security by design (2SBD) for high-temperature gas reactors, focusing on material control and accountability (MC&A). The motivation for the report is to provide 2SBD support to the Next Generation Nuclear Plant (NGNP) project, which was launched by Congress in 2005. This introductory section will provide some background on the NGNP project and an overview of the 2SBD concept. The remaining chapters focus specifically on design aspects of the candidate high-temperature gas reactors (HTGRs) relevant to MC&A, Nuclear Regulatory Commission (NRC) requirements, and proposed MC&A approaches for the two major HTGR reactormore » types: pebble bed and prismatic. Of the prismatic type, two candidates are under consideration: (1) GA's GT-MHR (Gas Turbine-Modular Helium Reactor), and (2) the Modular High-Temperature Reactor (M-HTR), a derivative of Areva's Antares reactor. The future of the pebble-bed modular reactor (PBMR) for NGNP is uncertain, as the PBMR consortium partners (Westinghouse, PBMR [Pty] and The Shaw Group) were unable to agree on the path forward for NGNP during 2010. However, during the technology assessment of the conceptual design phase (Phase 1) of the NGNP project, AREVA provided design information and technology assessment of their pebble bed fueled plant design called the HTR-Module concept. AREVA does not intend to pursue this design for NGNP, preferring instead a modular reactor based on the prismatic Antares concept. Since MC&A relevant design information is available for both pebble concepts, the pebble-bed HTGRs considered in this report are: (1) Westinghouse PBMR; and (2) AREVA HTR-Module. The DOE Office of Nuclear Energy (DOE-NE) sponsors the Fuel Cycle Research and Development program (FCR&D), which contains an element specifically focused on the domestic (or state) aspects of SBD. This Material Protection, Control and Accountancy Technology (MPACT) program supports the present work summarized in this report, namely the development of guidance to support the consideration of MC&A in the design of both pebble-bed and prismatic-fueled HTGRs. The objective is to identify and incorporate design features into the facility design that will cost effectively aid in making MC&A more effective and efficient, with minimum impact on operations. The theft of nuclear material is addressed through both MC&A and physical protection, while the threat of sabotage is addressed principally through physical protection.« less

HTGR technology economic/ business analysis and trade studies impacts. Impacts of HTGR commericialization on the U.S. economy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Silady, Fred

The approach to this task was to initially review the 2012 Business Plan and supporting analyses for the above impacts. With that understanding as a base, the Business Plan impacts are updated in terms of the GDP and job creation as a result of additional studies and inputs such as the revised market assessment from Task 1.1. For the impacts on U.S. competitiveness, the NGNP Industry Alliance team members have been utilized to provide inputs on supplier infrastructure development and on vendor capability.

Prognostic value of 6-minute walk corridor test in patients with mild to moderate heart failure: comparison with other methods of functional evaluation.

PubMed

Rostagno, Carlo; Olivo, Giuseppe; Comeglio, Marco; Boddi, Vieri; Banchelli, Michela; Galanti, Giorgio; Gensini, Gian Franco

2003-06-01

The study was designed to evaluate the prognostic value of the 6-min walk test (6MWT) in patients with mild to moderate congestive heart failure (CHF). Two hundred and fourteen patients (119 men and 95 women, mean age 64 years) were followed for a mean period of 34 months to assess event-free survival (death, heart transplantation). Sixty-six patients (34%) died (63 cardiovascular causes, 2 cancer and 1 stroke) and five patients underwent heart transplantation. For patients who walked <300 m during the 6MWT, survival was 62% compared with 82% in patients who walked 300-450 m or>450 m. With univariate analysis, NYHA class was the strongest predictor of death. LVEF (P<0.0001), aetiology of heart failure (P<0.001), LV filling pattern (P=0.002) and 6MWT distance (P<0.01) were all significantly related to survival. No significant relationship was found between survival, peak oxygen consumption or anaerobic threshold. Multivariate analysis using the Cox-stepwise regression model showed that LV fractional shortening (P<0.009) and 6MWT distance (P<0.0005) were the strongest prognostic markers. A 6MWT distance of <300 m is a simple and useful prognostic marker of subsequent cardiac death in unselected patients with mild to moderate CHF.

Hypoxemia and arrhythmia during daily activities and six-minute walk test in fibrotic interstitial lung diseases.

PubMed

Park, Jeong Hyun; Jegal, Yangjin; Shim, Tae Sun; Lim, Chae-Man; Lee, Sang Do; Koh, Younsuck; Kim, Woo Sung; Kim, Won Dong; du Bois, Roland; Do, Kyung-Hyun; Kim, Dong Soon

2011-03-01

We performed 24-hr monitoring of pulse oximetric saturation (SpO(2)) with ECG and six-minute walk test (6MWT) in 19 patients with fibrotic interstitial lung diseases (ILD) to investigate; 1) The frequency and severity of hypoxemia and dysrhythmia during daily activities and 6MWT, 2) safety of 6MWT, and 3) the parameters of 6MWT which can replace 24-hr continuous monitoring of SpO(2) to predict hypoxemia during daily activities. All patients experienced waking hour hypoxemia, and eight of nineteen patients spent > 10% of waking hours in hypoxemic state. Most patients experienced frequent arrhythmia, mostly atrial premature contractions (APCs) and ventricular premature contractions (VPCs). There were significant correlation between the variables of 6MWT and hypoxemia during daily activities. All of the patients who desaturated below 80% before 300 meters spent more than 10% of waking hour in hypoxemia (P = 0.018). In contrast to waking hour hypoxemia, SpO(2) did not drop significantly during sleep except in the patients whose daytime resting SpO(2) was already low. In conclusion, patients with fibrotic ILD showed significant period of hypoxemia during daily activities and frequent VPCs and APCs. Six-minute walk test is a useful surrogate marker of waking hour hypoxemia and seems to be safe without continuous monitoring of SpO(2).

The two-minute walk test as a measure of functional capacity in cardiac surgery patients.

PubMed

Brooks, Dina; Parsons, Janet; Tran, Diem; Jeng, Bonnie; Gorczyca, Barbara; Newton, Janet; Lo, Vincent; Dear, Cheryl; Silaj, Ellen; Hawn, Therese

2004-09-01

To examine construct validity and sensitivity of the two-minute walk test (2MWT) in cardiac surgery patients. Measurements were made in patients preoperatively, during the postoperative in-hospital stay, and 6 to 8 weeks after discharge from hospital. Ambulatory and hospitalized care. Patients (N=122; mean age +/- standard deviation, 63+/-9 y) undergoing coronary artery bypass grafting. Not applicable. The 2MWT, New York Heart Association (NYHA) functional classification for cardiac disease, the Nottingham Extended Activities of Daily Living scale, and the Medical Outcomes Survey 36-Item Short-Form Health Questionnaire (SF-36). Distance walked in 2 minutes decreased significantly postoperatively (from 138+/-26 m to 84+/-33 m, P<.001), but increased again at follow-up (151+/-31 m, P<.0001). Distance walked on the 2MWT correlated significantly to SF-36 (physical function subscale) preoperatively (r=.44) and at follow-up (r=.48) (P<.001). There was a significant difference in distance walked between those with NYHA class I and II compared with those classified as III or IV (P=.04). However, there was no significant difference in distance walked in 2 minutes between those who developed cardiac or pulmonary complications postoperatively (P> or =0.2). The 2MWT was sensitive to change after cardiac surgery and showed moderate correlation with measures of physical functioning in this population. However, the 2MWT could not identify those who developed complications in the postoperative period.

Measurement of Dyspnea in Ambulatory African Americans With Heart Failure and a Preserved or Reduced Ejection Fraction.

PubMed

Vuckovic, Karen M; DeVon, Holli A; Piano, Mariann R

2016-01-01

Dyspnea is a burdensome and disabling heart failure (HF) symptom. Few studies examining dyspnea in HF have included African Americans (AAs), despite their developing HF at a younger age and having the highest mortality rates. The purpose of this cross-sectional study was to examine dyspnea in AA patients with HF and a preserved ejection fraction (HFpEF) compared with those with a reduced ejection fraction (HFrEF), before and after the 6-minute walk test (6MWT). A convenience sample of ambulatory AA patients (HFrEF, n = 26; HFpEF, n = 19) 50 years or older was recruited from an urban HF clinic. The Borg Scale and a visual analog scale (VAS) were used to measure dyspnea intensity before and after the 6MWT. Activity limitations related to dyspnea were described using the modified Medical Research Council Dyspnea Scale. Group comparisons were analyzed using repeated-measures analysis of variance and χ 2tests. Convergent validity was determined between the Borg and VAS using Bland-Altman plots. No significant differences were found in age, gender, and comorbidities between HF groups. Most HFpEF patients reported dyspnea at baseline (Borg, 63%; VAS, 73%) and after the 6MWT (Borg, 78%; VAS, 79%). In the HFrEF group, the prevalence of baseline dyspnea was greater when measured with the VAS (Borg, 34%; VAS, 80%) but was similar between instruments after the 6MWT (Borg, 64%; VAS, 77%). Both groups reported a similar change in dyspnea intensity during and after the 6MWT. The Bland-Altman plots indicated moderate agreement at each time point. Most patients described walking hurriedly or uphill as dyspnea-provoking on the Modified Respiratory Council Dyspnea Scale. The prevalence of dyspnea at baseline and after the 6MWT was high for both groups, but intensity varied with the dyspnea instrument used.

Usefulness of the 6-minute walk test as a screening test for pulmonary arterial enlargement in COPD

PubMed Central

Oki, Yutaro; Kaneko, Masahiro; Fujimoto, Yukari; Sakai, Hideki; Misu, Shogo; Mitani, Yuji; Yamaguchi, Takumi; Yasuda, Hisafumi; Ishikawa, Akira

2016-01-01

Purpose Pulmonary hypertension and exercise-induced oxygen desaturation (EID) influence acute exacerbation of COPD. Computed tomography (CT)-detected pulmonary artery (PA) enlargement is independently associated with acute COPD exacerbations. Associations between PA to aorta (PA:A) ratio and EID in patients with COPD have not been reported. We hypothesized that the PA:A ratio correlated with EID and that results of the 6-minute walk test (6MWT) would be useful for predicting the risk associated with PA:A >1. Patients and methods We retrospectively measured lung function, 6MWT, emphysema area, and PA enlargement on CT in 64 patients with COPD. The patients were classified into groups with PA:A ≤1 and >1. Receiver-operating characteristic curves were used to determine the threshold values with the best cutoff points to predict patients with PA:A >1. Results The PA:A >1 group had lower forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), FEV1:FVC ratio, diffusion capacity of lung carbon monoxide, 6MW distance, and baseline peripheral oxygen saturation (SpO2), lowest SpO2, highest modified Borg scale results, percentage low-attenuation area, and history of acute COPD exacerbations ≤1 year, and worse BODE (Body mass index, airflow Obstruction, Dyspnea, and Exercise) index results (P<0.05). Predicted PA:A >1 was determined for SpO2 during 6MWT (best cutoff point 89%, area under the curve 0.94, 95% confidence interval 0.88–1). SpO2 <90% during 6MWT showed a sensitivity of 93.1, specificity of 94.3, positive predictive value of 93.1, negative predictive value of 94.3, positive likelihood ratio of 16.2, and negative likelihood ratio of 0.07. Conclusion Lowest SpO2 during 6MWT may predict CT-measured PA:A, and lowest SpO2 <89% during 6MWT is excellent for detecting pulmonary hypertension in COPD. PMID:27920514

Six-minute walk test and cardiopulmonary exercise testing in patients with chronic heart failure: a comparative analysis on clinical and prognostic insights.

PubMed

Guazzi, Marco; Dickstein, Kenneth; Vicenzi, Marco; Arena, Ross

2009-11-01

The six-minute walk test (6MWT) and cardiopulmonary exercise testing (CPET) are the 2 testing modalities most broadly used for assessing functional limitation in patients with heart failure (HF). A comprehensive comparison on clinical and prognostic validity of the 2 techniques has not been performed and is the aim of the present investigation. Two hundred fifty-three patients diagnosed with systolic (n=211) or diastolic (n=42) HF (age: 61.9+/-10.1 years; New York Heart Association Class: 2.2+/-0.78) underwent a 6MWT and a symptom-limited CPET evaluation and were prospectively followed up. During the 4-year tracking period, there were 43 cardiac-related deaths with an annual cardiac mortality rate of 8.7%. The 6MWT distance correlated with CPET-derived variables (ie, peak Vo(2), Vo(2) at anaerobic threshold, and Ve/Vco(2) slope) and was significantly reduced in proportion with lower peak Vo(2) and higher Ve/Vco(2) slope classes and presence of an exercise oscillatory breathing (EOB) pattern (P<0.01). However, no significant differences were observed in distance covered between survivors and nonsurvivors (353.2+/-95.8 m versus 338.5+/-76.4 m; P=NS). At univariate and multivariate Cox proportional analyses, the association of the 6MWT distance with survival was not significant either as a continuous or dicotomized variable (< or =300 m). Conversely, CPET-derived variables emerged as prognostic with the strongest association found for EOB (systolic HF) and Ve/Vco(2) slope (entire population with HF and patients with a 6MWT< or =300 m). The 6MWT is confirmed to be a simple and reliable first-line test for quantification of exercise intolerance in patients with HF. However, there is no supportive evidence for its use as a prognostic marker in alternative to or in conjunction with CPET-derived variables.

Preliminary LOCA analysis of the westinghouse small modular reactor using the WCOBRA/TRAC-TF2 thermal-hydraulics code

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liao, J.; Kucukboyaci, V. N.; Nguyen, L.

2012-07-01

The Westinghouse Small Modular Reactor (SMR) is an 800 MWt (> 225 MWe) integral pressurized water reactor (iPWR) with all primary components, including the steam generator and the pressurizer located inside the reactor vessel. The reactor core is based on a partial-height 17x17 fuel assembly design used in the AP1000{sup R} reactor core. The Westinghouse SMR utilizes passive safety systems and proven components from the AP1000 plant design with a compact containment that houses the integral reactor vessel and the passive safety systems. A preliminary loss of coolant accident (LOCA) analysis of the Westinghouse SMR has been performed using themore » WCOBRA/TRAC-TF2 code, simulating a transient caused by a double ended guillotine (DEG) break in the direct vessel injection (DVI) line. WCOBRA/TRAC-TF2 is a new generation Westinghouse LOCA thermal-hydraulics code evolving from the US NRC licensed WCOBRA/TRAC code. It is designed to simulate PWR LOCA events from the smallest break size to the largest break size (DEG cold leg). A significant number of fluid dynamics models and heat transfer models were developed or improved in WCOBRA/TRAC-TF2. A large number of separate effects and integral effects tests were performed for a rigorous code assessment and validation. WCOBRA/TRAC-TF2 was introduced into the Westinghouse SMR design phase to assist a quick and robust passive cooling system design and to identify thermal-hydraulic phenomena for the development of the SMR Phenomena Identification Ranking Table (PIRT). The LOCA analysis of the Westinghouse SMR demonstrates that the DEG DVI break LOCA is mitigated by the injection and venting from the Westinghouse SMR passive safety systems without core heat up, achieving long term core cooling. (authors)« less

Westinghouse Small Modular Reactor balance of plant and supporting systems design

DOE Office of Scientific and Technical Information (OSTI.GOV)

Memmott, M. J.; Stansbury, C.; Taylor, C.

2012-07-01

The Westinghouse Small Modular Reactor (SMR) is an 800 MWt (>225 MWe) integral pressurized water reactor (iPWR), in which all of the components typically associated with the nuclear steam supply system (NSSS) of a nuclear power plant are incorporated within a single reactor pressure vessel. This paper is the second in a series of four papers which describe the design and functionality of the Westinghouse SMR. It focuses, in particular, upon the supporting systems and the balance of plant (BOP) designs of the Westinghouse SMR. Several Westinghouse SMR systems are classified as safety, and are critical to the safe operationmore » of the Westinghouse SMR. These include the protection and monitoring system (PMS), the passive core cooling system (PXS), and the spent fuel cooling system (SFS) including pools, valves, and piping. The Westinghouse SMR safety related systems include the instrumentation and controls (I and C) as well as redundant and physically separated safety trains with batteries, electrical systems, and switch gears. Several other incorporated systems are non-safety related, but provide functions for plant operations including defense-in-depth functions. These include the chemical volume control system (CVS), heating, ventilation and cooling (HVAC) systems, component cooling water system (CCS), normal residual heat removal system (RNS) and service water system (SWS). The integrated performance of the safety-related and non-safety related systems ensures the safe and efficient operation of the Westinghouse SMR through various conditions and transients. The turbine island consists of the turbine, electric generator, feedwater and steam systems, moisture separation systems, and the condensers. The BOP is designed to minimize assembly time, shipping challenges, and on-site testing requirements for all structures, systems, and components. (authors)« less

Use of the six-minute walk test to characterize golden retriever muscular dystrophy.

PubMed

Acosta, Austin R; Van Wie, Emiko; Stoughton, William B; Bettis, Amanda K; Barnett, Heather H; LaBrie, Nicholas R; Balog-Alvarez, Cynthia J; Nghiem, Peter P; Cummings, Kevin J; Kornegay, Joe N

2016-12-01

Duchenne muscular dystrophy (DMD) is an X-linked recessive disorder in which loss of the dystrophin protein causes progressive skeletal/cardiac muscle degeneration and death within the third decade. For clinical trials and supportive animal studies, DMD disease progression and response to treatment must be established using outcome parameters (biomarkers). The 6-minute walk test (6MWT), defined as the distance an individual can walk in 6 minutes, is commonly used in DMD clinical trials and has been employed in dogs to characterize cardiac and respiratory disease severity. Building on methods established in DMD and canine clinical studies, we assessed the 6MWT in dogs with the DMD genetic homolog, golden retriever muscular dystrophy (GRMD). Twenty-one cross-bred golden retrievers were categorized as affected (DMD mutation and GRMD phenotype), carrier (female heterozygous for DMD mutation and no phenotype), and normal (wild type DMD gene and normal phenotype). When compared to grouped normal/carrier dogs, GRMD dogs walked shorter height-adjusted distances at 6 and 12 months of age and their distances walked declined with age. Percent change in creatine kinase after 6MWT was greater in GRMD versus normal/carrier dogs at 6 months, providing another potential biomarker. While these data generally support use of the 6MWT as a biomarker for preclinical GRMD treatment trials, there were certain limitations. Results of the 6MWT did not correlate with other outcome parameters for GRMD dogs when considered alone and an 80% increase in mean distance walked would be necessary to achieve satisfactory power. Copyright © 2016 Elsevier B.V. All rights reserved.

Optimization of biodegradable sponges as controlled release drug matrices. I. Effect of moisture level on chitosan sponge mechanical properties.

PubMed

Foda, Nagwa H; El-laithy, Hanan M; Tadros, Mina I

2004-04-01

Cross-linked chitosan sponges as controlled release drug carrier systems were developed. Tramadol hydrochloride, a centrally acting analgesic, was used as a model drug. The sponges were prepared by freeze-drying 1.25% and 2.5% (w/w) high and low M.wt. chitosan solutions, respectively, using glutaraldehyde as a cross-linking agent. The hardness of the prepared sponges was a function of glutaraldehyde concentration and volume where the optimum concentration that offered accepted sponge consistency was 5%. Below or above 5%, very soft or very hard and brittle sponges were obtained, respectively. The determined drug content in the prepared sponges was uniform and did not deviate markedly from the calculated amount. Scanning electron microscopy (SEM) was used to characterize the internal structures of the sponges. The SEM photos revealed that cross-linked high M.wt. chitosan sponges have larger size surface pores that form connections (channels) with the interior of the sponge than cross-linked low M.wt. ones. Moreover, crystals of the incorporated Tramadol hydrochloride were detected on the lamellae and within pores in both chitosan sponges. Differences in pore size and dissolution medium uptake capacity were crucial factors for the more delayed drug release from cross-linked low M.wt. chitosan sponges over high M.wt. ones at pH 7.4. Kinetic analysis of the release data using linear regression followed the Higuchi diffusion model over 12 hours. Setting storage conditions at room temperature under 80-92% relative humidity resulted in soft, elastic, and compressible sponges.

76 FR 26771 - Florida Power & Light Company; Turkey Point, Units 3 and 4; Notice of Consideration of Issuance...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-09

... Company; Turkey Point, Units 3 and 4; Notice of Consideration of Issuance of Amendment to Facility... issued to Florida Power & Light Co. (the licensee) for operation of the Turkey Point Nuclear Generating... licensed core power level for Turkey Point, Units 3 and 4, from 2300 megawatts thermal (MWt) to 2644 MWt...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rouxelin, Pascal Nicolas; Strydom, Gerhard

Best-estimate plus uncertainty analysis of reactors is replacing the traditional conservative (stacked uncertainty) method for safety and licensing analysis. To facilitate uncertainty analysis applications, a comprehensive approach and methodology must be developed and applied. High temperature gas cooled reactors (HTGRs) have several features that require techniques not used in light-water reactor analysis (e.g., coated-particle design and large graphite quantities at high temperatures). The International Atomic Energy Agency has therefore launched the Coordinated Research Project on HTGR Uncertainty Analysis in Modeling to study uncertainty propagation in the HTGR analysis chain. The benchmark problem defined for the prismatic design is represented bymore » the General Atomics Modular HTGR 350. The main focus of this report is the compilation and discussion of the results obtained for various permutations of Exercise I 2c and the use of the cross section data in Exercise II 1a of the prismatic benchmark, which is defined as the last and first steps of the lattice and core simulation phases, respectively. The report summarizes the Idaho National Laboratory (INL) best estimate results obtained for Exercise I 2a (fresh single-fuel block), Exercise I 2b (depleted single-fuel block), and Exercise I 2c (super cell) in addition to the first results of an investigation into the cross section generation effects for the super-cell problem. The two dimensional deterministic code known as the New ESC based Weighting Transport (NEWT) included in the Standardized Computer Analyses for Licensing Evaluation (SCALE) 6.1.2 package was used for the cross section evaluation, and the results obtained were compared to the three dimensional stochastic SCALE module KENO VI. The NEWT cross section libraries were generated for several permutations of the current benchmark super-cell geometry and were then provided as input to the Phase II core calculation of the stand alone neutronics Exercise II 1a. The steady state core calculations were simulated with the INL coupled-code system known as the Parallel and Highly Innovative Simulation for INL Code System (PHISICS) and the system thermal-hydraulics code known as the Reactor Excursion and Leak Analysis Program (RELAP) 5 3D using the nuclear data libraries previously generated with NEWT. It was observed that significant differences in terms of multiplication factor and neutron flux exist between the various permutations of the Phase I super-cell lattice calculations. The use of these cross section libraries only leads to minor changes in the Phase II core simulation results for fresh fuel but shows significantly larger discrepancies for spent fuel cores. Furthermore, large incongruities were found between the SCALE NEWT and KENO VI results for the super cells, and while some trends could be identified, a final conclusion on this issue could not yet be reached. This report will be revised in mid 2016 with more detailed analyses of the super-cell problems and their effects on the core models, using the latest version of SCALE (6.2). The super-cell models seem to show substantial improvements in terms of neutron flux as compared to single-block models, particularly at thermal energies.« less

Antitumor and synergistic effect of Chinese medicine “Bushen huayu jiedu recipe” and chemotherapy on transplanted animal hepatocarcinoma

PubMed Central

Cao, Yong; Xia, Qing-Hua; Meng, Hua; Zhong, An-Pu

2005-01-01

AIM: To investigate the antitumor and synergistic effect of Chinese medicine “Bushen huayu jiedu recipe” (recipe for invigorating the kidney, removing blood stasis and toxic substances) and chemotherapy on mice hepatocarcinoma. METHODS: Bushen huayu jiedu recipe (BSHYJDR) consisting of Chinese Cassia Bark, Psoralea, Zedoary, Rhubarb, etc. is equal to 1.5 g/mL liquid of originated herbs after being decocted, filtered, and concentrated. Kunming mice, weighing 18-22 g, were injected with 0.2 mL ascitic hepatocarcinoma H22 containing 1×107 cells/mL into armpit of the right forelimb of mice. After 24 h, the mice were weighed and randomly divided into tumor-bearing model control group, cisplatin (DDP) group, BSHYJDR high dosage group, low dosage BSHYJDR group, DDP combined with high and low dosage BSHYJDR group, 10 mice in each group. DDP group received injection intraperitoneally (ip) at the dosage of 1 mg/kg (equal to 1/10 LD50), once a day for 4 d. High and low dosage BSHYJDR groups received intragastric BSHYJDR at the dosages of 26.6 and 13.3 g/kg (20 and 10 times each of clinical adult dosage) respectively, while tumor-bearing model group received the equal volume of distilled water once a day for 10 d. On the 11th d, the mice were weighed and killed, then the tumor was dissected and weighed, the repression rate (RR) was calculated according to the mean weight of tumor (MWT). RESULTS: Compared to the model group (MWT: 1.30±0.73), DDP group (MWT: 0.41±0.09, RR: 68.46%) had a significant difference in the inhibition of hepatocarcinoma H22 (P<0.01). High dosage BSHYJDR group (MWT: 0.69±0.29, RR: 46.92%) also had a significant difference in inhibition (P<0.05), while no difference was found in low dosage BSHYJDR group (MWT: 0.85±0.34, RR: 34.62%) (P>0.05). When DDP was combined with high dosage BSHYJDR (MWT: 0.29±0.17, RR: 77.69%) and low dosage BSHYJDR (MWT: 0.38±0.21, RR: 70.77%) respectively, we could see improvement of the inhibition effect of DDP on transplanted hepatocarcinoma H22. DDP combined with high dosage BSHYJDR had a significant difference (P<0.001) compared to DDP, while DDP combined with low dosage BSHYJDR only had a little improvement that is not remarkable. CONCLUSION: Chinese medicine BSHYJDR in combination with chemotherapy can inhibit transplanted hepatocarcinoma in mice. PMID:16127756

The Six-Minute Walk Test for Adults with Intellectual Disability: A Study of Validity and Reliability

ERIC Educational Resources Information Center

Nasuti, Gabriella; Stuart-Hill, Lynneth; Temple, Viviene A.

2013-01-01

Background: The Six-Minute Walk Test (6MWT) has been used with clinical and healthy populations to assess functional capacity and cardiovascular fitness. The aim of this study was to determine the test-retest reliability of a modified-6MWT as well as concurrent validity of walk distance with peak oxygen uptake (VO[subscript 2] peak). Method:…

Heart Rate and Oxygen Saturation Change Patterns During 6-min Walk Test in Subjects With Chronic Thromboembolic Pulmonary Hypertension.

PubMed

Inagaki, Takeshi; Terada, Jiro; Yahaba, Misuzu; Kawata, Naoko; Jujo, Takayuki; Nagashima, Kengo; Sakao, Seiichiro; Tanabe, Nobuhiro; Tatsumi, Koichiro

2018-05-01

The 6-min walk test (6MWT) is commonly performed to assess functional status in patients with chronic thromboembolic pulmonary hypertension. However, changes in heart rate and oxygen saturation (S pO 2 ) patterns during 6MWT in patients with chronic thromboembolic pulmonary hypertension remain unclear. Thirty-one subjects with chronic thromboembolic pulmonary hypertension were retrospectively evaluated to examine the relationships between the change in heart rate (Δheart rate), heart rate acceleration time, slope of heart rate acceleration, heart rate recovery during the first minute after 6MWT (HRR1), change in S pO 2 (ΔS pO 2 ), S pO 2 reduction time, and S pO 2 recovery time during 6MWT, and the severity of pulmonary hemodynamics assessed by right heart catheterization and echocardiography. Subjects with severe chronic thromboembolic pulmonary hypertension had significantly longer heart rate acceleration time (144.9 ± 63.9 s vs 96.0 ± 42.5 s, P = .033), lower Δheart rate (47.4 ± 16.9 vs 61.8 ± 13.6 beats, P = .02), and lower HRR1 (13.3 ± 9.0 beats vs 27.1 ± 9.2 beats, P < .001) compared to subjects with mild chronic thromboembolic pulmonary hypertension. Subjects with severe chronic thromboembolic pulmonary hypertension also had significantly longer S pO 2 reduction time (178.3 ± 70.3 s vs 134.3 ± 58.4 s, P = .03) and S pO 2 recovery time (107.6 ± 35.3 s vs 69.8 ± 32.7 s, P = .004) than did subjects with mild chronic thromboembolic pulmonary hypertension. Multivariate linear regression analysis showed only mean pulmonary arterial pressure independently was associated with heart rate acceleration time and slope of heart rate acceleration. Heart rate and S pO 2 change patterns during 6MWT are predominantly associated with pulmonary hemodynamics in subjects with chronic thromboembolic pulmonary hypertension. Evaluating heart rate and S pO 2 change patterns during 6MWT may serve as a safe and convenient way to follow the change in pulmonary hemodynamics. Copyright © 2018 by Daedalus Enterprises.

Physical Performance Measures Associated With Locomotive Syndrome in Middle-Aged and Older Japanese Women.

PubMed

Nakamura, Misa; Hashizume, Hiroshi; Oka, Hiroyuki; Okada, Morihiro; Takakura, Rie; Hisari, Ayako; Yoshida, Munehito; Utsunomiya, Hirotoshi

2015-01-01

The Japanese Orthopaedic Association proposed a concept called locomotive syndrome (LS) to identify middle-aged and older adults at high risk of requiring health care services because of problems with locomotion. It is important to identify factors associated with the development of LS. Physical performance measures such as walking speed and standing balance are highly predictive of subsequent disability and mortality in older adults. However, there is little evidence about the relationship between physical performance measures and LS. To determine the physical performance measures associated with LS, the threshold values for discriminating individuals with and without LS, and the odds ratio of LS according to performance greater than or less than these thresholds in middle-aged and older Japanese women. Participants were 126 Japanese women (mean age = 61.8 years). Locomotive syndrome was defined as a score of 16 or more on the 25-question Geriatric Locomotive Function Scale. Physical performance was evaluated using grip strength, unipedal stance time with eyes open, seated toe-touch, and normal and fast 6-m walk time (6 MWT). Variables were compared between LS and non-LS groups. Fourteen participants (11.1%) were classed as having LS. Unipedal stance time, normal 6 MWT, and fast 6 MWT were significantly different between the 2 groups. The LS group had a shorter unipedal stance time and a longer normal and fast 6 MWT than the non-LS group. For these 3 variables, the area under the receiver operating characteristic curve was greater than 0.7, and the threshold for discriminating the non-LS and LS groups was 15 s for unipedal stance time, 4.8 s for normal 6 MWT and 3.6 s for fast 6 MWT. These variables were entered into a multiple logistic regression analysis, which indicated that unipedal stance time less than 15 s was significantly related to LS (odds ratio = 8.46; P < .01). Unipedal stance time was the physical performance measure that was most strongly associated with LS. This measure may be useful for early detection of LS.

Comparative study of four physical performance measures as predictors of death, incident disability, and falls in unselected older persons: the insufficienza Cardiaca negli Anziani Residenti a Dicomano Study.

PubMed

Minneci, Cristina; Mello, Anna Maria; Mossello, Enrico; Baldasseroni, Samuele; Macchi, Loredana; Cipolletti, Stefano; Marchionni, Niccolò; Di Bari, Mauro

2015-01-01

To compare the ability of the Short Physical Performance Battery (SPPB), 4-m walk test (4mWT), 6-minute walk test (6MWT), and handgrip strength to predict mortality, incident disability, worsening mobility, and falls in older community dwellers. Cohort study. Population-based. Individuals aged 65 and older n = 561) without prevalent basic activity of daily living (ADL) disability participating. Separate logistic regression models were developed to predict incident ADL disability, worsening mobility, and falls in 3 years, and Cox regression models were used to assess 7-year risk of death as a function of the four tests, adjusting for covariates. Performance tests were reciprocally correlated at baseline. After 3 years, 33 (7.3%) of 453 participants reexamined were disabled in ADLs, 87 (20%) had worsening mobility, and 99 (22%) reported falls. Of the 561 baseline participants, 141 (25%) died over the 7 years. All measures predicted incident ADL disability, with adjusted odds ratios (ORs) per unit increase of 0.85 (95% confidence interval (CI) = 0.77-0.93) for handgrip strength, 0.08 (95% CI = 0.02-0.36) for 4mWT, 0.74 (95% CI = 0.61-0.89) for SPPB, and 0.993 (95% CI = 0.988-0.997) for 6MWT. Handgrip strength (OR = 0.88, 95% CI = 0.83-0.93), 4mWT (OR = 0.33, 95% CI = 0.11-0.94), and SPPB (OR = 0.81, 95%CI = 0.71-0.93) predicted worsening mobility. No measure predicted falls; only SPPB (hazard ratio (HR) = 0.92, 95% CI = 0.85-0.997) and 6MWT (HR = 0.997, 95% CI = 0.995-0.999) predicted death. Performance measures are independent predictors of relevant health outcomes, with the exception of falls. Because SPPB is easily applied and is the only measure predicting incident ADL disability, worsening mobility, and death, it is preferable to the other tests. © 2015, Copyright the Authors Journal compilation © 2015, The American Geriatrics Society.

Left ventricular markers of global dyssynchrony predict limited exercise capacity in heart failure, but not in patients with preserved ejection fraction.

PubMed

Bajraktari, Gani; Batalli, Arlind; Poniku, Afrim; Ahmeti, Artan; Olloni, Rozafa; Hyseni, Violeta; Vela, Zana; Morina, Besim; Tafarshiku, Rina; Vela, Driton; Rashiti, Premtim; Haliti, Edmond; Henein, Michael Y

2012-09-11

The aim of this study was to prospectively examine echocardiographic parameters that correlate and predict functional capacity assessed by 6 min walk test (6-MWT) in patients with heart failure (HF), irrespective of ejection fraction (EF). In 147 HF patients (mean age 61 ± 11 years, 50.3% male), a 6-MWT and an echo-Doppler study were performed in the same day. Global LV dyssynchrony was indirectly assessed by total isovolumic time - t-IVT [in s/min; calculated as: 60 - (total ejection time + total filling time)], and Tei index (t-IVT/ejection time). Patients were divided into two groups based on the 6-MWT distance (Group I: ≤ 300 m and Group II: >300 m), and also in two groups according to EF (Group A: LVEF ≥ 45% and Group B: LVEF < 45%). In the cohort of patients as a whole, the 6-MWT correlated with t-IVT (r = -0.49, p < 0.001) and Tei index (r = -0.43, p < 0.001) but not with any of the other clinical or echocardiographic parameters. Group I had lower hemoglobin level (p = 0.02), lower EF (p = 0.003), larger left atrium (p = 0.02), thicker interventricular septum (p = 0.02), lower A wave (p = 0.01) and lateral wall late diastolic myocardial velocity a' (p = 0.047), longer isovolumic relaxation time (r = 0.003) and longer t-IVT (p = 0.03), compared with Group II. In the patients cohort as a whole, only t-IVT ratio [1.257 (1.071-1.476), p = 0.005], LV EF [0.947 (0.903-0.993), p = 0.02], and E/A ratio [0.553 (0.315-0.972), p = 0.04] independently predicted poor 6-MWT performance (<300 m) in multivariate analysis. None of the echocardiographic measurements predicted exercise tolerance in HFpEF. In patients with HF, the limited exercise capacity, assessed by 6-MWT, is related mostly to severity of global LV dyssynchrony, more than EF or raised filling pressures. The lack of exercise predictors in HFpEF reflects its multifactorial pathophysiology.

Respiratory muscle strength and pulmonary function in children with rhinitis and asthma after a six-minute walk test.

PubMed

Soares, Ana Alice de Almeida; Barros, Camila Moraes; Santos, Cássia Giulliane Costa; Dos Santos, Maria Renata Aragão; Silva, José Rodrigo Santos; Silva Junior, Walderi Monteiro da; Simões, Silvia de Magalhães

2018-03-01

Rhinitis and asthma decrease quality of life. Few studies have assessed the performance of children with asthma or rhinitis under submaximal exercise. We evaluated maximal respiratory pressures, spirometric parameters, and ability to sustain submaximal exercise in these children before and after the 6-minute walk test (6MWT), compared to healthy children. This cross-sectional, analytical study included 89 children aged 6-12 years in outpatient follow-up: 27 healthy (H), 31 with rhinitis (R), and 31 with mild asthma under control (A). Pulmonary function parameters and maximal respiratory pressures were measured before and 5, 10, and 30 minutes after the 6MWT. Wilcoxon test was used to compare numerical numerical variables between two groups and analysis of variance or Kruskal-Wallis test for comparison among three groups. Total distance traveled in the 6MWT was similar among the three groups. Compared to pre-test values, VEF1 (Forced Expiratory Volume in 1 second), VEF0.75 (Forced Expiratory Volume in 0.75 second), and FEF25-75 (Forced Expiratory Flow 25-75% of the Forced Vital Capacity - CVF - curve) decreased significantly after the 6MWT in group A, and VEF0.75, FEF25-75, and VEF1/CVF decreased significantly in group R. Groups A and R had lower Maximum Inspiratory Pressure values than group H before and after the 6MWT at all time points assessed. The findings suggest that children with rhinitis and mild asthma present with alterations in respiratory muscle strength and pulmonary function not associated with clinical complaints, reinforcing the concept of the united airways.

Multimedia Exercise Training Program Improves Distance Walked, Heart Rate Recovery, and Self-efficacy in Cardiac Surgery Patients.

PubMed

Wang, Li-Wei; Ou, Shu-Hua; Tsai, Chien-Sung; Chang, Yue-Cune; Kao, Chi-Wen

2016-01-01

Patient education has been shown to be more effective when delivered using multimedia than written materials. However, the effects of using multimedia to assist patients in cardiac rehabilitation have not been investigated. The purpose of this study is to examine the effect of an inpatient multimedia exercise training program on distance walked in the 6-minute walking test (6MWT), heart rate recovery, and walking self-efficacy of patients who had undergone heart surgery. For this longitudinal quasi-experimental study, 60 consecutive patients were assigned to an experimental (n = 20; inpatient multimedia exercise training program) or control (n = 40; routine care) group. Data were collected at 3 times (before surgery, 1 to 2 days before hospital discharge, and 1 month after hospital discharge) and analyzed with the generalized estimating equation approach. Most subjects were men (66.7%), had a mean age of 61.32 ± 13.4 years and left ventricular ejection fraction of 56.96% ± 13.28%, and underwent coronary artery bypass graft surgery (n = 34, 56.7%). Subjects receiving the exercise training program showed significantly greater improvement than those in the control group in the 6MWT walking distance (P < .001), heart rate recovery (P = .04), and self-efficacy (P = .002) at hospital discharge. Furthermore, the intervention effects on 6MWT distance (P < .001) and self-efficacy (P < .001) were sustained at 1 month after hospital discharge. Our inpatient multimedia exercise training program safely improved distance walked in the 6MWT, heart rate recovery, and self-efficacy at hospital discharge in patients after heart surgery and maintained their improvement in 6MWT and self-efficacy 1 month later.

The importance of exercise self-efficacy for clinical outcomes in pulmonary rehabilitation.

PubMed

Selzler, Anne-Marie; Rodgers, Wendy M; Berry, Tanya R; Stickland, Michael K

2016-11-01

Pulmonary rehabilitation (PR) improves functional exercise capacity and health status in people with chronic obstructive pulmonary disease (COPD), although these outcomes are often not maintained following PR. Self-efficacy is a precursor to outcomes achievement, yet few studies have examined the importance of self-efficacy to outcome improvement during PR, or how it develops over time. Further, the contribution of exercise-specific self-efficacy to outcomes in PR is unknown. The aims of this study were to determine (a) whether baseline exercise self-efficacy predicts PR attendance and change in functional exercise capacity and health status over PR, and (b) if exercise self-efficacy changes with PR. Fifty-eight out of 64 patients with COPD completed PR and assessments of exercise self-efficacy (task, coping, scheduling), the 6-minute walk test (6MWT), and St. George's Respiratory Questionnaire (SGRQ) at the beginning and end of PR. Analyses were conducted to predict attendance, and change in 6MWT and SGRQ, while controlling for baseline demographic and clinical indicators. Change in 6MWT, SGRQ, and self-efficacy with PR was also examined. Clinically significant increases in the 6MWT and SGRQ were achieved with PR. Stronger task self-efficacy predicted better attendance, while stronger coping self-efficacy predicted greater 6MWT improvement. No variables predicted SGRQ change. Scheduling self-efficacy significantly improved with PR, whereas task and coping self-efficacy did not. Baseline exercise self-efficacy appears to be a determinant of rehabilitation attendance and functional exercise improvement with PR. Clinicians should evaluate and target exercise self-efficacy to maximize adherence and health outcome improvement with PR. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Daytime Sleepiness and Driving Performance in Patients with Obstructive Sleep Apnea: Comparison of the MSLT, the MWT, and a Simulated Driving Task

PubMed Central

Pizza, Fabio; Contardi, Sara; Mondini, Susanna; Trentin, Lino; Cirignotta, Fabio

2009-01-01

Study Objectives: To test the reliability of a driving-simulation test for the objective measurement of daytime alertness compared with the Multiple Sleep Latency Test (MSLT) and with the Maintenance of Wakefulness Test (MWT), and to test the ability to drive safely, in comparison with on-road history, in the clinical setting of untreated severe obstructive sleep apnea. Design: N/A. Setting: Sleep laboratory. Patients or Participants: Twenty-four patients with severe obstructive sleep apnea and reported daytime sleepiness varying in severity (as measured by the Epworth Sleepiness Scale). Interventions: N/A. Measurements and Results: Patients underwent MSLT and MWT coupled with 4 sessions of driving-simulation test on 2 different days randomly distributed 1 week apart. Simulated-driving performance (in terms of lane-position variability and crash occurrence) was correlated with sleep latency on the MSLT and more significantly on the MWT, showing a predictive validity toward the detection of sleepy versus alert patients with obstructive sleep apnea. In addition, patients reporting excessive daytime sleepiness or a history of car crashes showed poorer performances on the driving simulator. Conclusions: A simulated driving test is a suitable tool for objective measurement of daytime alertness in patients with obstructive sleep apnea. Further studies are needed to clarify the association between simulated-driving performance and on-road crash risk of patients with sleep disordered breathing. Citation: Pizza F; Contardi S; Mondini S; Trentin L; Cirignotta F. Daytime sleepiness and driving performance in patients with obstructive sleep apnea: comparison of the MSLT, the MWT, and a simulated driving task. SLEEP 2009;32(3):382-391. PMID:19294958

Secondary Heat Exchanger Design and Comparison for Advanced High Temperature Reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Piyush Sabharwall; Ali Siahpush; Michael McKellar

2012-06-01

The goals of next generation nuclear reactors, such as the high temperature gas-cooled reactor and advance high temperature reactor (AHTR), are to increase energy efficiency in the production of electricity and provide high temperature heat for industrial processes. The efficient transfer of energy for industrial applications depends on the ability to incorporate effective heat exchangers between the nuclear heat transport system and the industrial process heat transport system. The need for efficiency, compactness, and safety challenge the boundaries of existing heat exchanger technology, giving rise to the following study. Various studies have been performed in attempts to update the secondarymore » heat exchanger that is downstream of the primary heat exchanger, mostly because its performance is strongly tied to the ability to employ more efficient conversion cycles, such as the Rankine super critical and subcritical cycles. This study considers two different types of heat exchangers—helical coiled heat exchanger and printed circuit heat exchanger—as possible options for the AHTR secondary heat exchangers with the following three different options: (1) A single heat exchanger transfers all the heat (3,400 MW(t)) from the intermediate heat transfer loop to the power conversion system or process plants; (2) Two heat exchangers share heat to transfer total heat of 3,400 MW(t) from the intermediate heat transfer loop to the power conversion system or process plants, each exchanger transfers 1,700 MW(t) with a parallel configuration; and (3) Three heat exchangers share heat to transfer total heat of 3,400 MW(t) from the intermediate heat transfer loop to the power conversion system or process plants. Each heat exchanger transfers 1,130 MW(t) with a parallel configuration. A preliminary cost comparison will be provided for all different cases along with challenges and recommendations.« less

Reducing The Cost of Transport and Increasing Walking Distance After Stroke: A Randomized Controlled Trial on Fast Locomotor Training Combined With Functional Electrical Stimulation

PubMed Central

Awad, Louis N.; Reisman, Darcy S.; Pohlig, Ryan T.; Binder-Macleod, Stuart A.

2015-01-01

Background Neurorehabilitation efforts have been limited in their ability to restore walking function after stroke. Recent work has demonstrated proof-of-concept for a Functional Electrical Stimulation (FES)-based combination therapy designed to improve poststroke walking by targeting deficits in paretic propulsion. Objectives To determine the effects on the energy cost of walking (EC) and long-distance walking ability of locomotor training that combines fast walking with FES to the paretic ankle musculature (FastFES). Methods Fifty participants >6 months poststroke were randomized to 12 weeks of gait training at self-selected speeds (SS), fast speeds (Fast), or FastFES. Participants’ 6-Minute Walk Test (6MWT) distance and EC at comfortable (EC-CWS) and fast (EC-Fast) walking speeds were measured pretraining, posttraining, and at a 3-month follow-up. A reduction in EC-CWS, independent of changes in speed, was the primary outcome. Also evaluated were group differences in the number of 6MWT responders and moderation by baseline speed. Results When compared with SS and Fast, FastFES produced larger reductions in EC (p’s ≤0.03). FastFES produced reductions of 24% and 19% in EC-CWS and EC-Fast (p’s <0.001), whereas neither Fast nor SS influenced EC. Between-group 6MWT differences were not observed; however, 73% of FastFES and 68% of Fast participants were responders, in contrast to 35% of SS participants. Conclusions Combining fast locomotor training with FES is an effective approach to reducing the high EC of persons poststroke. Surprisingly, differences in 6MWT gains were not observed between groups. Closer inspection of the 6MWT and EC relationship and elucidation of how reduced EC may influence walking-related disability is warranted. PMID:26621366

Assessment of cardiovascular function following transcatheter aortic valve implantation based on six-minute walk test.

PubMed

Chodór, Piotr; Wilczek, Krzysztof; Zielińska, Teresa; Przybylski, Roman; Głowacki, Jan; Włoch, Łukasz; Zembala, Marian; Kalarus, Zbigniew

2017-01-01

Transcatheter aortic valve implantation (TAVI) is presently a recognized treatment mo-dality for patients with severe aortic stenosis ineligible for surgery. It reduces mortality as compared to the conservative treatment. It is further expected from this therapy to improve quality of life by improving of the cardiovascular function performance. The aim of this study is to compare patients' cardiovascular system efficiency in the 6-minute walk test (6MWT) made before and after TAVI and at the 6-12-month follow-up. From January 2009 until February 2012, in the Silesian Center for Heart Diseases in Zabrze, TAVI was performed in 104 patients. Eighty-two patients who underwent 6MWT before surgery were qualified for the analysis. The average age of the patients was 76.0 ± 9.17 years, women made 45.1%. The risk of surgical treatment according to the Logistic Euroscore averaged 22.76 ± 12.63%, and by the Society of Thoracic Surgeons - 5.55 ± 3.34%. The 6MWT was performed within 1 month before the TAVI procedure, up to a month after the procedure and during the 6-12-month follow-up. The 6-minute walk test after TAVI was performed by 64 patients, and after 6-12 month follow-up by 46 patients. The average distance in 6MWT increased from 268.4 ± 89.0 m before treat-ment to 290.0 ± 98.2 m after the procedure (p = 0.008) and 276.1 ± 93.5 m to 343.1 ± 96.7 m after 6-12 months (p < 0.0001). Transcatheter aortic valve implantation procedures significantly improve function of the cardiovascular system evaluated by the 6MWT in 1- and 6-12-month observations. (Cardiol J 2017; 24, 2: 167-175).

Reliability and validity of the 6-min walk test in adults and seniors with intellectual disabilities.

PubMed

Guerra-Balic, Myriam; Oviedo, Guillermo R; Javierre, Casimiro; Fortuño, Jesús; Barnet-López, Silvia; Niño, Oscar; Alamo, Juan; Fernhall, Bo

2015-12-01

Adults with intellectual disabilities (ID) have significantly lower rates of physical activity and fitness than adults without ID. The 6-min walk test (6 MWT) is an inexpensive and simple way to test mobility and submaximal work capacity. To evaluate the test-retest reliability and validity of the 6 MWT in adults and seniors with ID and explore factors contributing to the 6 MWT distance (6 MWD). 46 participants with mild, moderate and severe ID levels (age=41 ± 11 years) performed the 6 MWT three times (T1; T2; T3) to determine test-retest reliability. To test validity, peak oxygen uptake (VO2 peak) was measured using a treadmill protocol. To analyze factors contributing to the 6 MWD, sex, height, fat mass % and fat free mass %, ID level, isometric leg strength and relative VO2 peak were also measured. The walking distances for T1, T2 and T3 were 460.3 ± 76.9; 489.4 ± 81.2 and 491.4 ± 77.9 m, respectively. The 6 MWDs between T1-T2 and T1-T3 were significantly different (p<0.001), but T2 and T3 were not different. The intraclass correlation coefficient between T2 and T3 was 0.96 indicating high reliability. Relative VO2 peak and isometric leg strength significantly contributed to the 6 MWD (R(2)=0.55). The 6 MWT is an easy, inexpensive, reliable and valid test in adults and seniors with ID. Familiarization is necessary to obtain reliable values. Relative VO2 peak and leg strength have significant impact on the distance walked. Copyright © 2015 Elsevier Ltd. All rights reserved.

Air travel and chronic obstructive pulmonary disease: a new algorithm for pre-flight evaluation.

PubMed

Edvardsen, Anne; Akerø, Aina; Christensen, Carl C; Ryg, Morten; Skjønsberg, Ole H

2012-11-01

The reduced pressure in the aircraft cabin may cause significant hypoxaemia and respiratory distress in patients with chronic obstructive pulmonary disease (COPD). Simple and reliable methods for predicting the need for supplemental oxygen during air travel have been requested. To construct a pre-flight evaluation algorithm for patients with COPD. In this prospective, cross-sectional study of 100 patients with COPD referred to hypoxia-altitude simulation test (HAST), sea level pulse oximetry at rest (SpO(2 SL)) and exercise desaturation (SpO(2 6MWT)) were used to evaluate whether the patient is fit to fly without further assessment, needs further evaluation with HAST or should receive in-flight supplemental oxygen without further evaluation. HAST was used as the reference method. An algorithm was constructed using a combination of SpO(2 SL) and SpO(2 6MWT). Categories for SpO(2 SL) were >95%, 92-95% and <92%, the cut-off value for SpO(2 6MWT) was calculated as 84%. Arterial oxygen pressure (PaO(2 HAST)) <6.6 kPa was the criterion for recommending supplemental oxygen. This algorithm had a sensitivity of 100% and a specificity of 80% when tested prospectively on an independent sample of patients with COPD (n=50). Patients with SpO(2 SL) >95% combined with SpO(2 6MWT) ≥84% may travel by air without further assessment. In-flight supplemental oxygen is recommended if SpO(2 SL)=92-95% combined with SpO(2 6MWT) <84% or if SpO(2 SL) <92%. Otherwise, HAST should be performed. The presented algorithm is simple and appears to be a reliable tool for pre-flight evaluation of patients with COPD.

Toll-like receptor 2 mediates mesenchymal stem cell-associated myocardial recovery and VEGF production following acute ischemia-reperfusion injury

PubMed Central

Abarbanell, Aaron M.; Wang, Yue; Herrmann, Jeremy L.; Weil, Brent R.; Poynter, Jeffrey A.; Manukyan, Mariuxi C.

2010-01-01

Toll-like receptor 2 (TLR2), a key component of the innate immune system, is linked to inflammation and myocardial dysfunction after ischemia-reperfusion injury (I/R). Treatment of the heart with mesenchymal stem cells (MSCs) is known to improve myocardial recovery after I/R in part by paracrine factors such as VEGF. However, it is unknown whether TLR2 activation on the MSCs affects MSC-mediated myocardial recovery and VEGF production. We hypothesized that the knockout of TLR2 on the MSCs (TLR2KO MSCs) would 1) improve MSC-mediated myocardial recovery and 2) increase myocardial and MSC VEGF release. With the isolated heart perfusion system, Sprague-Dawley rat hearts were subjected to I/R and received one of three intracoronary treatments: vehicle, male wild-type MSCs (MWT MSCs), or TL2KO MSCs. All treatments were performed immediately before ischemia, and heart function was measured continuously. Postreperfusion, heart homogenates were analyzed for myocardial VEGF production. Contrary to our hypothesis, only MWT MSC treatment significantly improved the recovery of left ventricular developed pressure and the maximal positive and negative values of the first derivative of pressure. In addition, VEGF production was greatest in hearts treated with MWT MSCs. To investigate MSC production of VEGF, MSCs were activated with TNF in vitro and the supernatants collected for ELISA. In vitro basal levels of MSC VEGF production were similar. However, with TNF activation, MWT MSCs produced significantly more VEGF, whereas activated TLR2KO MSC production of VEGF was unchanged. Finally, we observed that MWT MSCs proliferated more rapidly than TLR2KO MSCs. These data indicate that TLR2 may be essential to MSC-mediated myocardial recovery and VEGF production. PMID:20173040

Safety of early performance of the six-minute walk test following acute myocardial infarction: a cross-sectional study.

PubMed

Diniz, Lívia S; Neves, Victor R; Starke, Ana C; Barbosa, Marco P T; Britto, Raquel R; Ribeiro, Antônio L P

The six-minute walk test (6MWT) is a simple, low cost, reliable, and valid method for evaluating the functional capacity of cardiac patients. However, its early use and safety following acute myocardial infarction (AMI) is recent and has been little investigated. To evaluate and to compare the safety and the cardiac behavior of early performance of the 6MWT in patients following uncomplicated AMI up to 4 days or more than 4 days after the event. Following discharge from the Coronary Care Unit, 152 stable asymptomatic patients diagnosed with uncomplicated AMI performed the 6MWT. During the test, in addition to the distance walked, heart rate (HR), blood pressure (BP), and adverse events were also recorded. Electrocardiography was recorded using a Holter monitor in 105 patients. Patients were allocated considering two groups according to the number of days since AMI: Up to 4 Days Group and After 4 Days Group. All patients completed the 6MWT, 66 in the Up to 4 Days Group and 86 in the After 4 Days Group. The walking distance was similar in both groups (85% of the predicted value), as well as the physiological responses (increase in systolic BP and HR), reaching 63% (median) of maximum HR. Only 3.9% of patients had major complications (angina, drop in BP, or ventricular tachycardia), with no difference between the groups. None of the complications regarded as severe led to truly significant complications or death. The 6MWT was proven to be safe and feasible for early functional evaluation following uncomplicated AMI. Copyright © 2017 Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia. Publicado por Elsevier Editora Ltda. All rights reserved.

What is a meaningful change in physical performance? Findings from a clinical trial in older adults (the LIFE-P study).

PubMed

Kwon, S; Perera, S; Pahor, M; Katula, J A; King, A C; Groessl, E J; Studenski, S A

2009-06-01

Performance measures provide important information, but the meaning of change in these measures is not well known. The purpose of this research is to 1) examine the effect of treatment assignment on the relationship between self-report and performance; 2) to estimate the magnitude of meaningful change in 400-meter walk time (400MWT), 4-meter gait speed (4MGS), and Short Physical Performance Battery (SPPB) and 3) to evaluate the effect of direction of change on estimates of magnitude. This is a secondary analysis of data from the LIFE-P study, a single blinded randomized clinical trial. Using change over one year, we applied distribution-based and anchor-based methods for self-reported mobility to estimate minimally important and substantial change in 400MWT, 4MGS and SPPB. Four university-based clinical research sites. Sedentary adults aged 70-89 whose SPPB scores were less than 10 and who were able to complete a 400MW at baseline (n=424). A structured exercise program versus health education. 400MWT, 4MGS, SPPB. Relationships between self-report and performance measures were consistent between treatment arms. Minimally significant change estimates were 400MWT: 20-30 seconds, 4MGS: 0.03-0.05m/s and SPPB: 0.3 - 0.8 points. Substantial changes were 400MWT: 50-60 seconds, 4MGS: 0.08m/s, SPPB: 0.4 - 1.5 points. Magnitudes of change for improvement and decline were not significantly different. The magnitude of clinically important change in physical performance measures is reasonably consistent using several analytic techniques and appears to be achievable in clinical trials of exercise. Due to limited power, the effect of direction of change on estimates of magnitude remains uncertain.

Six-minute walk test as a determinant of the functional capacity of children and adolescents with cystic fibrosis: A systematic review.

PubMed

Andrade Lima, Cibelle; Dornelas de Andrade, Armèle; Campos, Shirley Lima; Brandão, Daniella Cunha; Mourato, Ianny Pereira; Britto, Murilo Carlos Amorim de

2018-04-01

Cystic Fibrosis (CF) is a multisystem disorder. The involvement of the respiratory system is frequent and culminates in dyspnea and exercise intolerance. Functional capacity is an important diagnostic tool, because it reflects the cardiorespiratory status, quality of life and prognosis. This systematic review aims to assess the reproducibility and validity of the six minute walk test (6MWT) to reflect the functional capacity of children and adolescents with cystic fibrosis, and also the correlation between 6MWT and lung function. Searches for articles were performed in eight databases using MeSH/DeCS keywords. A total of 695 articles were found and, after verifying all eligibility criteria, six articles were included for analysis and scoring regarding the methodological quality according to the QUADAS scale (Quality Assessment of Diagnostic Accuracy Studies). All articles had good methodology (QUADAS between 9 and 11 points). The 6MWT is not correlated with lung function. There is a strong indication that the 6MWT is a reproducible test to assess the functional capacity of children and adolescents with CF. The validity assessment could not be reached because the studies included in this systematic review did not use adequate statistical tools to carry out such an evaluation. Copyright © 2018 Elsevier Ltd. All rights reserved.

Comparing Treatment Effect Measurements in Narcolepsy: The Sustained Attention to Response Task, Epworth Sleepiness Scale and Maintenance of Wakefulness Test.

PubMed

van der Heide, Astrid; van Schie, Mojca K M; Lammers, Gert Jan; Dauvilliers, Yves; Arnulf, Isabelle; Mayer, Geert; Bassetti, Claudio L; Ding, Claire-Li; Lehert, Philippe; van Dijk, J Gert

2015-07-01

To validate the Sustained Attention to Response Task (SART) as a treatment effect measure in narcolepsy, and to compare the SART with the Maintenance of Wakefulness Test (MWT) and the Epworth Sleepiness Scale (ESS). Validation of treatment effect measurements within a randomized controlled trial (RCT). Ninety-five patients with narcolepsy with or without cataplexy. The RCT comprised a double-blind, parallel-group, multicenter trial comparing the effects of 8-w treatments with pitolisant (BF2.649), modafinil, or placebo (NCT01067222). MWT, ESS, and SART were administered at baseline and after an 8-w treatment period. The severity of excessive daytime sleepiness and cataplexy was also assessed using the Clinical Global Impression scale (CGI-C). The SART, MWT, and ESS all had good reliability, obtained for the SART and MWT using two to three sessions in 1 day. The ability to distinguish responders from nonresponders, classified using the CGI-C score, was high for all measures, with a high performance for the SART (r = 0.61) and the ESS (r = 0.54). The Sustained Attention to Response Task is a valid and easy-to-administer measure to assess treatment effects in narcolepsy, enhanced by combining it with the Epworth Sleepiness Scale. © 2015 Associated Professional Sleep Societies, LLC.

ICP-MS measurement of silver diffusion coefficient in graphite IG-110 between 1048K and 1284K

NASA Astrophysics Data System (ADS)

Carter, L. M.; Seelig, J. D.; Brockman, J. D.; Robertson, J. D.; Loyalka, S. K.

2018-01-01

Silver-110m has been shown to permeate intact silicon carbide and pyrolytic carbon coating layers of the TRISO fuel particles during normal High Temperature Gas-Cooled Reactor (HTGR) operational conditions. The diffusion coefficients for silver in graphite IG-110 measured using a release method designed to simulate HTGR conditions of high temperature and flowing helium in the temperature range 1048-1253 K are reported. The measurements were made using spheres milled from IG-110 graphite that were infused with silver using a pressure vessel technique. The Ag diffusion was measured using a time release technique with an ICP-MS instrument for detection. The results of this work are:

HTGR plant availability and reliability evaluations. Volume I. Summary of evaluations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cadwallader, G.J.; Hannaman, G.W.; Jacobsen, F.K.

1976-12-01

The report (1) describes a reliability assessment methodology for systematically locating and correcting areas which may contribute to unavailability of new and uniquely designed components and systems, (2) illustrates the methodology by applying it to such components in a high-temperature gas-cooled reactor (Public Service Company of Colorado's Fort St. Vrain 330-MW(e) HTGR), and (3) compares the results of the assessment with actual experience. The methodology can be applied to any component or system; however, it is particularly valuable for assessments of components or systems which provide essential functions, or the failure or mishandling of which could result in relatively largemore » economic losses.« less

Measuring Steady-State Oxygen Uptake during the 6-Min Walk Test in Adults with Cerebral Palsy: Feasibility and Construct Validity

ERIC Educational Resources Information Center

Maltais, Desiree B.; Robitaille, Nancy-Michelle; Dumas, Francine; Boucher, Normand; Richards, Carol L.

2012-01-01

This study evaluated the feasibility of measuring steady-state oxygen uptake (V[Combining Dot Above]O[subscript 2]) during the 6-min walk test (6MWT) in adults with cerebral palsy (CP) who walk without support and whether there is construct validity for net 6MWT V[Combining Dot Above]O[subscript 2] as a measure of their walking ability.…

Alternate Tritium Production Methods Using A Liquid Lithium Target

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilson, J.

For over 60 years, the Savannah River Site’s primary mission has been the production of tritium. From the beginning, the Savannah River National Laboratory (SRNL) has provided the technical foundation to ensure the successful execution of this critical defense mission. SRNL has developed most of the processes used in the tritium mission and provides the research and development necessary to supply this critical component. This project was executed by first developing reactor models that could be used as a neutron source. In parallel to this development calculations were carried out testing the feasibility of accelerator technologies that could also bemore » used for tritium production. Targets were designed with internal moderating material and optimized target was calculated to be capable of 3000 grams using a 1400 MWt sodium fast reactor, 850 grams using a 400 MWt sodium fast reactor, and 100 grams using a 62 MWt reactor, annually.« less

Irradiation performance of HTGR fuel rods in HFIR experiments HRB-7 and -8

DOE Office of Scientific and Technical Information (OSTI.GOV)

Valentine, K.H.; Homan, F.J.; Long, E.L. Jr.

1977-05-01

The HRB-7 and -8 experiments were designed as a comprehensive test of mixed thorium-uranium oxide fissile particles with Th:U ratios from 0 to 8 for HTGR recycle application. In addition, fissile particles derived from Weak-Acid Resin (WAR) were tested as a potential backup type of fissile particle for HTGR recycle. These experiments were conducted at two temperatures (1250 and 1500/sup 0/C) to determine the influence of operating temperature on the performance parameters studied. The minor objectives were comparison of advanced coating designs where ZrC replaced SiC in the Triso design, testing of fuel coated in laboratory-scale equipment with fuel coatedmore » in production-scale coaters, comparison of the performance of /sup 233/U-bearing particles with that of /sup 235/U-bearing particles, comparison of the performance of Biso coatings with Triso coatings for particles containing the same type of kernel, and testing of multijunction tungsten-rhenium thermocouples. All objectives were accomplished. As a result of these experiments the mixed thorium-uranium oxide fissile kernel was replaced by a WAR-derived particle in the reference recycle design. A tentative decision to make this change had been reached before the HRB-7 and -8 capsules were examined, and the results of the examination confirmed the accuracy of the previous decision. Even maximum dilution (Th/U approximately equal to 8) of the mixed thorium-uranium oxide kernel was insufficient to prevent amoeba of the kernels at rates that are unacceptable in a large HTGR. Other results showed the performance of /sup 233/U-bearing particles to be identical to that of /sup 235/U-bearing particles, the performance of fuel coated in production-scale equipment to be at least as good as that of fuel coated in laboratory-scale coaters, the performance of ZrC coatings to be very promising, and Biso coatings to be inferior to Triso coatings relative to fission product retention.« less

ICP-MS analysis of fission product diffusion in graphite for High-Temperature Gas-Cooled Reactors

NASA Astrophysics Data System (ADS)

Carter, Lukas M.

Release of radioactive fission products from nuclear fuel during normal reactor operation or in accident scenarios is a fundamental safety concern. Of paramount importance are the understanding and elucidation of mechanisms of chemical interaction, nuclear interaction, and transport phenomena involving fission products. Worldwide efforts to reduce fossil fuel dependence coupled with an increasing overall energy demand have generated renewed enthusiasm toward nuclear power technologies, and as such, these mechanisms continue to be the subjects of vigorous research. High-Temperature Gas-Cooled Reactors (HTGRs or VHTRs) remain one of the most promising candidates for the next generation of nuclear power reactors. An extant knowledge gap specific to HTGR technology derives from an incomplete understanding of fission product transport in major core materials under HTGR operational conditions. Our specific interest in the current work is diffusion in reactor graphite. Development of methods for analysis of diffusion of multiple fission products is key to providing accurate models for fission product release from HTGR core components and the reactor as a whole. In the present work, a specialized diffusion cell has been developed and constructed to facilitate real-time diffusion measurements via ICP-MS. The cell utilizes a helium gas-jet system which transports diffusing fission products to the mass spectrometer using carbon nanoparticles. The setup was designed to replicate conditions present in a functioning HTGR, and can be configured for real-time release or permeation measurements of single or multiple fission products from graphite or other core materials. In the present work, we have analyzed release rates of cesium in graphite grades IG-110, NBG-18, and a commercial grade of graphite, as well as release of iodine in IG-110. Additionally we have investigated infusion of graphite samples with Cs, I, Sr, Ag, and other surrogate fission products for use in release or profile measurements of diffusion coefficients.

Left ventricular markers of global dyssynchrony predict limited exercise capacity in heart failure, but not in patients with preserved ejection fraction

PubMed Central

2012-01-01

Background The aim of this study was to prospectively examine echocardiographic parameters that correlate and predict functional capacity assessed by 6 min walk test (6-MWT) in patients with heart failure (HF), irrespective of ejection fraction (EF). Methods In 147 HF patients (mean age 61 ± 11 years, 50.3% male), a 6-MWT and an echo-Doppler study were performed in the same day. Global LV dyssynchrony was indirectly assessed by total isovolumic time - t-IVT [in s/min; calculated as: 60 – (total ejection time + total filling time)], and Tei index (t-IVT/ejection time). Patients were divided into two groups based on the 6-MWT distance (Group I: ≤300 m and Group II: >300 m), and also in two groups according to EF (Group A: LVEF ≥ 45% and Group B: LVEF < 45%). Results In the cohort of patients as a whole, the 6-MWT correlated with t-IVT (r = −0.49, p < 0.001) and Tei index (r = −0.43, p < 0.001) but not with any of the other clinical or echocardiographic parameters. Group I had lower hemoglobin level (p = 0.02), lower EF (p = 0.003), larger left atrium (p = 0.02), thicker interventricular septum (p = 0.02), lower A wave (p = 0.01) and lateral wall late diastolic myocardial velocity a’ (p = 0.047), longer isovolumic relaxation time (r = 0.003) and longer t-IVT (p = 0.03), compared with Group II. In the patients cohort as a whole, only t-IVT ratio [1.257 (1.071-1.476), p = 0.005], LV EF [0.947 (0.903-0.993), p = 0.02], and E/A ratio [0.553 (0.315-0.972), p = 0.04] independently predicted poor 6-MWT performance (<300 m) in multivariate analysis. None of the echocardiographic measurements predicted exercise tolerance in HFpEF. Conclusion In patients with HF, the limited exercise capacity, assessed by 6-MWT, is related mostly to severity of global LV dyssynchrony, more than EF or raised filling pressures. The lack of exercise predictors in HFpEF reflects its multifactorial pathophysiology. PMID:22966942

Fabrication methods and anisotropic properties of graphite matrix compacts for use in HTGR

NASA Astrophysics Data System (ADS)

Yeo, Sunghwan; Yun, Jihae; Kim, Sungok; Cho, Moon Sung; Lee, Young-Woo

2018-02-01

This study investigated the anisotropic microstructural, mechanical, and thermal properties of fabricated graphite matrix prismatic compacts for High Temperature Gas Cooled Reactor (HTGR) fuel. When the observed alignment of graphite grains and the coke derived from phenolic resin is in the transverse direction, the result is severely anisotropic thermal properties. Compacts with such orientation in the transverse direction exhibited increases of thermal expansion and conductivity up to 5.8 times and 4.82 times, respectively, more than those in the axial direction. The formation of pores due to the pyrolysis of phenolic resin was observed predominantly on upper region of the fabricated compacts. This anisotropic pore formation created anisotropic Vickers hardness on the planes with different directions.

Impacts of harvesting and postharvest treatments on soil bulk density, soil strength, and ealry growth of Pinus taeda in the Gulf Coastal Plain: a long-term soil productivity affiliated study

Treesearch

Mason C. Carter; Thomas J. Dean; Ziyin Wang; Ray A. Newbold

2006-01-01

At four sites in the Gulf Coastal Plain, mechanical whole-tree harvesting (MWT) removed from biomass and nutrients than hand-fell bole-only harvesting (HFBO). Soil compaction and loblolly pine (Pinus taeda L.) regeneration growth varied among sites. At one location, MWT increased soil bulk density by 0.1 Mgm-3, from 1.14 to 1....

Role of pulmonary hemodynamics in determining 6-minute walk test result in atrial septal defect: an observational study.

PubMed

Supomo, Supomo; Darmawan, Handy; Arjana, Adika Zhulhi

2018-05-22

The presence of altered pulmonary hemodynamics in adult patients with atrial septal defect (ASD) is common. However, there are no observational studies which evaluate the impact of altered pulmonary hemodynamics on the 6-min walk test (6MWT) result. This study aimed to investigate the role of pulmonary hemodynamics in determining 6MWT result of patients with ASD. Forty-six consecutive adult patients with ASD were included in this study. Right heart catheterization was performed to obtain the pulmonary hemodynamics profile. Meanwhile, 6MWT was presented as high or low with cut-off point 350 m. Receiver operating characteristic (ROC) was used for analytical methods. Abnormal functional capacity was indicated by ROC result of mPAP cut-off value of > 24 mmHg (p = 0.0243; AUC = 0.681). The value of PVR > 3.42 woods unit (WU) showed high specificity in determining abnormal functional capacity (p = 0.0069; AUC = 0.713). Flow ratio with cut-off point ≤4.89 had the highest sensitivity (100%) (p = 0.8300; AUC = 0.520). Pulmonary hemodynamics can serve as an indicator of 6MWT result in adult ASD patients with values of mPAP> 24 mmHg and PVR > 3.42 WU.

Impact of Preemptive Analgesia on inflammatory responses and Rehabilitation after Primary Total Knee Arthroplasty: A Controlled Clinical Study.

PubMed

Jianda, Xu; Yuxing, Qu; Yi, Gao; Hong, Zhao; Libo, Peng; Jianning, Zhao

2016-08-31

The aim of this study was to investigate the effects of preemptive analgesia on the inflammatory response and rehabilitation in TKA. 75 patients with unilateral primary knee osteoarthritis were conducted in this prospective study. All patients were randomly divided into two groups (MMA with/without preemptive analgesia group). The following parameters were used to evaluate analgesic efficacy: knee flexion, pain at rest and walking, functional walking capacity (2 MWT and 6 MWT), WOMAC score, and hs-CRP level. Patients in MMA with preemptive analgesia group had lower hs-CRP level and less pain at rest and walking during the first week postoperatively (P < 0.05). The 2 MWT was significantly better in MMA with preemptive analgesia group (17.13 ± 3.82 VS 14.19 ± 3.56, P = 0.001). The 6 MWT scores and WOMAC scores increased significantly within Groups (P = 0.020, 0.000), but no difference between groups postoperatively (P > 0.05). Less cumulative consumption of morphine was found in MMA with preemptive analgesia group at 48 h (P = 0.017, 0.023), but no difference at total requirement (P = 0.113). Preemptive analgesia added to a multimodal analgesic regime improved analgesia, reduced inflammatory reaction and accelerated functional recovery at the first week postoperatively, but not improved long-term function.

The six-minute walk test in patients with AL amyloidosis: a single centre case series.

PubMed

Pulido, Vina; Doros, Gheorghe; Berk, John L; Sanchorawala, Vaishali

2017-05-01

The six-minute walk test (6MWT) has been widely used as an objective evaluation of functional exercise capacity and response to medical intervention in cardiopulmonary diseases. However, little is known about the 6MWT in evaluating patients with AL amyloidosis. We performed a retrospective study of 120 adults with systemic AL amyloidosis (60 with cardiac involvement and 60 without cardiac involvement) who had their initial evaluation at the Amyloidosis Center between 2013 and 2015 and had undergone 6MWT as a measure of functional exercise capacity. Forty-seven patients with cardiac involvement and 41 patients without cardiac involvement were included in the final analysis. The six-minute walk distances (6MWD) were 368 ± 105 m and 420 ± 116 m (mean ± SD), respectively (P = 0·03). Among AL amyloidosis patients with cardiac involvement, the 6MWD was associated with New York Heart Association class (P < 0·001), B-type natriuretic peptide (P = 0·003) and overall survival (hazard ratio 0·381, 95% confidence interval 0·215-0·676, P = 0·001). In conclusion, the 6MWT is a valuable tool in assessing functional exercise capacity in patients with AL amyloidosis. © 2017 John Wiley & Sons Ltd.

The clinical significance of 10-m walk test standardizations in Parkinson's disease.

PubMed

Lindholm, Beata; Nilsson, Maria H; Hansson, Oskar; Hagell, Peter

2018-06-06

The 10-m walk test (10MWT) is a widely used measure of gait speed in Parkinson's disease (PD). However, it is unclear if different standardizations of its conduct impact test results. We examined the clinical significance of two aspects of the standardization of the 10MWT in mild PD: static vs. dynamic start, and a single vs. repeated trials. Implications for fall prediction were also explored. 151 people with PD (mean age and PD duration, 68 and 4 years, respectively) completed the 10MWT in comfortable gait speed with static and dynamic start (two trials each), and gait speed (m/s) was recorded. Participants then registered all prospective falls for 6 months. Absolute mean differences between outcomes from the various test conditions ranged between 0.016 and 0.040 m/s (effect sizes, 0.06-0.14) with high levels of agreement (intra-class correlation coefficients, 0.932-0.987) and small standard errors of measurement (0.032-0.076 m/s). Receiver operating characteristic curves showed similar discriminate abilities for prediction of future falls across conditions (areas under curves, 0.70-0.73). Cut-off points were estimated at 1.1-1.2 m/s. Different 10MWT standardizations yield very similar results, suggesting that there is no practical need for an acceleration distance or repeated trials when conducting this test in mild PD.

Oral Chinese Herbal Medicine Combined with Pharmacotherapy for Stable COPD: A Systematic Review of Effect on BODE Index and Six Minute Walk Test

PubMed Central

Chen, Xiankun; May, Brian; Di, Yuan Ming; Zhang, Anthony Lin; Lu, Chuanjian; Xue, Charlie Changli; Lin, Lin

2014-01-01

This systematic review evaluated the effects of Chinese herbal medicine (CHM) plus routine pharmacotherapy (RP) on the objective outcome measures BODE index, 6-minute walk test (6MWT), and 6-minute walk distance (6MWD) in individuals with stable chronic obstructive pulmonary disease (COPD). Searches were conducted of six English and Chinese databases (PubMed, EMBASE, CENTRAL, CINAHL, CNKI and CQVIP) from their inceptions until 18th November 2013 for randomized controlled trials involving oral administration of CHM plus RP compared to the same RP, with BODE Index and/or 6MWT/D as outcomes. Twenty-five studies were identified. BODE Index was used in nine studies and 6MWT/D was used in 22 studies. Methodological quality was assessed using the Cochrane Risk of Bias tool. Weaknesses were identified in most studies. Six studies were judged as ‘low’ risk of bias for randomisation sequence generation. Twenty-two studies involving 1,834 participants were included in the meta-analyses. The main meta-analysis results showed relative benefits for BODE Index in nine studies (mean difference [MD] −0.71, 95% confidence interval [CI] −0.94, −0.47) and 6MWT/D in 17 studies (MD 54.61 meters, 95%CI 33.30, 75.92) in favour of the CHM plus RP groups. The principal plants used were Astragalus membranaceus, Panax ginseng and Cordyceps sinensis. A. membranaceus was used in combination with other herbs in 18 formulae in 16 studies. Detailed sub-group and sensitivity analyses were conducted. Clinically meaningful benefits for BODE Index and 6MWT were found in multiple studies. These therapeutic effects were promising but need to be interpreted with caution due to variations in the CHMs and RPs used and methodological weakness in the studies. These issues should be addressed in future trials. PMID:24622390

Is there an optimal level of positive expiratory pressure (PEP) to improve walking tolerance in patients with severe COPD?

PubMed

Russo, Davide; Simonelli, Carla; Paneroni, Mara; Saleri, Manuela; Piroddi, Ines Maria Grazia; Cardinale, Francesco; Vitacca, Michele; Nicolini, Antonello

2016-07-01

The application of positive expiratory pressure (PEP) devices during exercise had been proposed in order to counteract the pulmonary hyperinflation, reduce the dyspnea and thus increase the exercise tolerance in patients with severe chronic obstructive pulmonary disease (COPD). This randomized controlled crossover trial investigated the effect of two different levels of PEP (1 cmH2O and 10 cmH2O) on distance covered at 6minute walk test (6MWT) in patients with severe COPD. Secondary outcomes were the evaluation of PEP effects on physiological and pulmonary function variables. Seventy-two severe COPD patients, referred to our hospitals as in and out patients, were recruited. A basal 6MWT without devices was performed on the first day, and then repeated with PEP 1 cmH2O (PEP1) and 10 cmH2O (PEP10), with a randomized crossover design. Slow and forced spirometries, including the inspiratory capacity measure, were repeated before and after each 6MWT. 50 patients (average age 69,92 year, mean FEV1 41,42% of predicted) concluded the trial. The 6MWT improved significantly among both PEP levels and baseline (323,8 mt at baseline vs. 337,8 PEP1 and 341,8 PEP10; p<.002 and p<.018, respectively). The difference between PEP10 and PEP1 did not reach the significance. No improvements were found in pulmonary function, symptoms and physiological variables after the 6MWT. In patients with severe COPD, the application of 1 cmH2O of PEP seems to improve the exercise tolerance as 10 cmH2O, with similar dyspnea. Further studies should investigate the effects of low levels of PEP on aerobic training programs. Copyright © 2016 SEPAR. Published by Elsevier Espana. All rights reserved.

Diagnostic value of the six-minute walk test (6MWT) in grown-up congenital heart disease (GUCH): Comparison with clinical status and functional exercise capacity.

PubMed

Kehmeier, Eva S; Sommer, Margot H; Galonska, Anika; Zeus, Tobias; Verde, Pablo; Kelm, Malte

2016-01-15

Exercise testing for the assessment of functional capacity plays an important role in long-term follow-up of GUCH patients. CPX is the favored modality for decision-making recommended in the current guidelines. In contrast to this complex method, the 6 MWT is a simple, easy-to-perform, safe, and commonly available exercise test. Although well-established in various cardiopulmonary diseases, the diagnostic impact of the 6 MWT in GUCH patients is not known so far. 102 GUCH patients were evaluated by 6 MWT and CPX simultaneously. Clinical symptoms were assessed, according to the NYHA classification. Additionally, an echocardiography study, and selected cardiac blood tests (N-terminal pro-brain natriuretic peptide (NT-proBNP), high-sensitive Troponin T) were performed. Ranges of six-minute walk distance (6 MWD) and peak oxygen consumption (peakVO2) were 116-765 m and 6.4-36.2 ml/kg/min, respectively. 6 MWD and peakVO2 showed a close correlation (r=0.72, 95% CI, 0.63 to 0.79). Patients with a peakVO2 of ≤ 15.5 ml/kg/min were excellently identified by 6 MWT (c-value=0.82). A cut-off value of 482 m was optimal to predict reduced peakVO2. In multivariate regression analysis, 6 MWD and NYHA class were identified as relevant predictors of peakVO2. In subgroup analysis, Eisenmenger patients achieved the shortest 6 MWD (280, SD 178 m). In our study population of GUCH patients, the 6 MWD shows a close correlation to peakVO2, and an excellent prediction of reduced peakVO2. Thus, it seems to be an easy-to-perform and reliable screening parameter to evaluate functional capacity of these patients (Controlled Clinical Trials number, NCT02193243). Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The six-minute walk test as a measure of postoperative recovery after colorectal resection: further examination of its measurement properties.

PubMed

Pecorelli, Nicolò; Fiore, Julio F; Gillis, Chelsia; Awasthi, Rashami; Mappin-Kasirer, Benjamin; Niculiseanu, Petru; Fried, Gerald M; Carli, Francesco; Feldman, Liane S

2016-06-01

Patients, clinicians and researchers seek an easy, reproducible and valid measure of postoperative recovery. The six-minute walk test (6MWT) is a low-cost measure of physical function, which is a relevant dimension of recovery. The aim of the present study was to contribute further evidence for the validity of the 6MWT as a measure of postoperative recovery after colorectal surgery. This study involved a sample of 174 patients enrolled in three previous randomized controlled trials. Construct validity was assessed by testing the hypotheses that the distance walked in 6 min (6MWD) at 4 weeks after surgery is greater (1) in younger versus older patients, (2) in patients with higher preoperative physical status versus lower, (3) after laparoscopic versus open surgery, (4) in patients without postoperative complications versus with postoperative complications; and that 6MWD (5) correlates cross-sectionally with self-reported physical activity as measured with a questionnaire (CHAMPS). Statistical analysis was performed using linear regression and Spearman's correlation. The COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist was used to guide the formulation of hypotheses and reporting of results. One hundred and fifty-one patients who completed the 6MWT at 4 weeks after surgery were included in the analysis. All hypotheses tested for construct validity were supported by the data. Older age, poorer physical status, open surgery and occurrence of postoperative complications were associated with clinically relevant reduction in 6MWD (>19 m). There was a moderate positive correlation between 6MWD and patient-reported physical activity (r = 0.46). This study contributes further evidence for the construct validity of the 6MWT as a measure of postoperative recovery after colorectal surgery. Results from this study support the use of the 6MWT as an outcome measure in studies evaluating interventions aimed to improve postoperative recovery.

Reliability, construct validity and determinants of 6-minute walk test performance in patients with chronic heart failure.

PubMed

Uszko-Lencer, Nicole H M K; Mesquita, Rafael; Janssen, Eefje; Werter, Christ; Brunner-La Rocca, Hans-Peter; Pitta, Fabio; Wouters, Emiel F M; Spruit, Martijn A

2017-08-01

In-depth analyses of the measurement properties of the 6-minute walk test (6MWT) in patients with chronic heart failure (CHF) are lacking. We investigated the reliability, construct validity, and determinants of the distance covered in the 6MWT (6MWD) in CHF patients. 337 patients were studied (median age 65years, 70% male, ejection fraction 35%). Participants performed two 6MWTs on subsequent days. Demographics, anthropometrics, clinical data, ejection fraction, maximal exercise capacity, body composition, lung function, and symptoms of anxiety and depression were also assessed. Construct validity was assessed in terms of convergent, discriminant and known-groups validity. Stepwise linear regression was used. 6MWT was reliable (ICC=0.90, P<0.0001). The learning effect was 31m (95%CI 27, 35m). Older age (≥65years), lower lung diffusing capacity (<80% predicted) and higher NYHA class (NYHA III) were associated with a lower likelihood of a meaningful increase in the second test (OR 0.45-0.56, P<0.05 for all). The best 6MWD had moderate-to-good correlations with peak exercise capacity (r s =0.54-0.69) and no-to-fair correlations with body composition, lung function, ejection fraction, and symptoms of anxiety and depression (r s =0.04-0.49). Patients with higher NYHA classes had lower 6MWD. 6MWD was independently associated with maximal power output during maximal exercise, estimated glomerular filtration rate and age (51.7% of the variability). 6MWT was found to be reliable and valid in patients with mild-to-moderate CHF. Maximal exercise capacity, renal function and age were significant determinants of the best 6MWD. These findings strengthen the clinical utility of the 6MWT in CHF. Copyright © 2017 Elsevier B.V. All rights reserved.

Characteristics and determinants of endurance cycle ergometry and six-minute walk distance in patients with COPD.

PubMed

Andrianopoulos, Vasileios; Wagers, Scott S; Groenen, Miriam T J; Vanfleteren, Lowie E; Franssen, Frits M E; Smeenk, Frank W J M; Vogiatzis, Ioannis; Wouters, Emiel F M; Spruit, Martijn A

2014-05-31

Exercise tolerance can be assessed by the cycle endurance test (CET) and six-minute walk test (6MWT) in patients with Chronic Obstructive Pulmonary Disease (COPD). We sought to investigate the characteristics of functional exercise performance and determinants of the CET and 6MWT in a large clinical cohort of COPD patients. A dataset of 2053 COPD patients (43% female, age: 66.9 ± 9.5 years, FEV1% predicted: 48.2 ± 23.2) was analyzed retrospectively. Patients underwent, amongst others, respiratory function evaluation; medical tests and questionnaires, one maximal incremental cycle test where peak work rate was determined and two functional exercise tests: a CET at 75% of peak work rate and 6MWT. A stepwise multiple linear regression was used to assess determinants. On average, patients had impaired exercise tolerance (peak work rate: 56 ± 27% predicted, 6MWT: 69 ± 17% predicted). A total of 2002 patients had CET time of duration (CET-Tend) less than 20 min while only 51 (2.5%) of the patients achieved 20 min of CET-Tend . In former patients, the percent of predicted peak work rate achieved differed significantly between men (48 ± 21% predicted) and women (67 ± 31% predicted). In contrast, CET-Tend was longer in men (286 ± 174 s vs 250 ± 153 s, p < 0.001). Also, six minute walking distance (6MWD) was higher in men compared to women, both in absolute terms as in percent of predicted (443 m, 67%predicted vs 431 m, 72%predicted, p < 0.05). Gender was associated with the CET-Tend but BMI, FEV1 and FRC were related to the 6MWD highlighting the different determinants of exercise performance between CET and 6MWT. CET-Tend is a valuable outcome of CET as it is related to multiple clinical aspects of disease severity in COPD. Gender difference should temper the interpretation of CET.

Longitudinal analysis of endurance and respiratory function from a natural history study of Morquio A syndrome.

PubMed

Harmatz, Paul R; Mengel, Karl Eugen; Giugliani, Roberto; Valayannopoulos, Vassili; Lin, Shuan-Pei; Parini, Rossella; Guffon, Nathalie; Burton, Barbara K; Hendriksz, Christian J; Mitchell, John J; Martins, Ana Maria; Jones, Simon A; Guelbert, Norberto; Vellodi, Ashok; Wijburg, Frits A; Yang, Ke; Slasor, Peter; Decker, Celeste

2015-02-01

Baseline data from the Morquio A Clinical Assessment Program (MorCAP) revealed that individuals with Morquio A syndrome show substantial impairment in multiple domains including endurance and respiratory function (Harmatz et al., Mol Genet Metab, 2013). Here, 1- and 2-year longitudinal endurance and respiratory function data are presented. Endurance was assessed using the 6-minute walk test (6MWT) and the 3-minute stair climb test (3MSCT). Respiratory function was evaluated by measuring forced vital capacity (FVC) and maximum voluntary ventilation (MVV). Data were analyzed using repeated measures ANCOVA models. Annualized estimates of change were determined using model estimates and interpolation. 353, 184, and 78 subjects were assessed at Year 0 (baseline), Year 1, and Year 2, respectively. The overall annualized estimate of change (SE) in 6MWT distance was -4.86±3.25m; a larger decline of -6.84±5.38m was observed in the subset of subjects meeting the inclusion/exclusion criteria of the Phase 3 clinical trial of elosulfase alfa (≥5years of age with baseline 6MWT distance ≥30 and ≤325m). In contrast, little change (-0.14±0.60stairs/min) was observed in 3MSCT. Annualized changes (SE) in FVC and MVV were 2.44±0.68% and 1.01±2.38%, respectively. FVC and MVV increased in patients aged ≤14years, but decreased in older patients. The natural history of Morquio A syndrome is characterized by progressive impairment of endurance as measured by the 6MWT. Longitudinal trends in FVC and MVV showing increase in younger patients, but decrease in older patients, are likely to be influenced by growth. Changes in 6MWT may represent a sensitive measure of disease progression in ambulatory Morquio A patients. Copyright © 2014. Published by Elsevier Inc.

Role of Anti-Inflammatory Cytokines on Muscle Mass and Performance Changes in Elderly Men and Women.

PubMed

Rossi, A P; Budui, S; Zoico, E; Caliari, C; Mazzali, G; Fantin, F; D'Urbano, M; Paganelli, R; Zamboni, M

2017-01-01

Investigate the presence of a correlation between systemic inflammatory profile of community-dwelling individuals and the loss of muscular mass and performance in old age over a 4.5y follow-up, focusing on the role of anti-inflammatory cytokines in muscular changes in elderly. Longitudinal clinical study. Subjects were randomly selected from lists of 11 general practitioners in the city of Verona, Italy. The study included 120 subjects, 92 women and 28 men aged 72.27±2.06 years and with BMI of 26.52±4.07 kg/m2 at baseline. Six minutes walking test (6MWT), appendicular and leg fat free mass (FFM) as measured with Dual Energy X-ray absorptiometry, were obtained at baseline and after 4.5 years (4.5y) of mean follow-up. Height, weight, body mass index (BMI), and circulating levels of TNFα, IL-4, IL-10, and IL-13 were evaluated at baseline. A significant reduction of appendicular FFM, leg FFM and 6MWT performance (all p<0.001) was observed after 4.5 y follow-up. In a stepwise regression model, considering appendicular FFM decline as dependent variable, lnIL-4, BMI, baseline appendicular FFM, lnTNFα and lnIL-13 were significant predictors of appendicular FFM decline explaining 30.8% of the variance. While building a stepwise multiple regression considering leg FFM as a dependent variable, lnIL-4, BMI and leg FFM were significant predictors of leg FFM decline and explained 27.4% of variance. When considering 6MWT decline as a dependent variable, baseline 6MWT, lnIL-13 and lnTNFα were significant predictors of 6MWT decline to explain 22.9% of variance. Our study suggest that higher serum levels of anti-inflammatory markers, and in particular IL-4 and IL-13, may play a protective role on FFM and performance maintenance in elderly subjects.

Severe combined immunodeficiency in Sting V154M/WT mice.

PubMed

Bouis, Delphine; Kirstetter, Peggy; Arbogast, Florent; Lamon, Delphine; Delgado, Virginia; Jung, Sophie; Ebel, Claudine; Jacobs, Hugues; Knapp, Anne-Marie; Jeremiah, Nadia; Belot, Alexandre; Martin, Thierry; Crow, Yanick J; André-Schmutz, Isabelle; Korganow, Anne-Sophie; Rieux-Laucat, Frédéric; Soulas-Sprauel, Pauline

2018-05-23

Autosomal dominant gain-of-function (GOF) mutations in human STING (Stimulator of Interferon Genes) lead to a severe autoinflammatory disease called SAVI (STING Associated Vasculopathy with onset in Infancy), associated with enhanced expression of interferon (IFN) stimulated gene (ISG) transcripts. The goal of this study was to analyze the phenotype of a new mouse model of Sting hyperactivation, and the role of type I IFN in this system. We generated a knock-in model carrying an amino acid substitution (V154M) in mouse Sting, corresponding to a recurrent mutation seen in human patients with SAVI. Hematopoietic development and tissue histology were analyzed. Lymphocyte activation and proliferation were assessed in vitro. Sting V154M/WT mice were crossed to IFNAR (IFNα/β Receptor) knock-out mice in order to evaluate the type I IFN-dependence of the mutant Sting phenotype recorded. In Sting V154M/WT mice we detected variable expression of inflammatory infiltrates in the lungs and kidneys. These mice showed a marked decrease in survival and developed a severe combined immunodeficiency disease (SCID) affecting B, T and NK cells, with an almost complete lack of antibodies and a significant expansion of monocytes and granulocytes. The blockade in B and T cell development was present from early immature stages in bone marrow and thymus. In addition, in vitro experiments revealed an intrinsic proliferative defect of mature T cells. Whilst the V154M/WT mutant demonstrated increased expression of ISGs, the SCID phenotype was not reversed in Sting V154M/WT IFNAR knock-out mice. However, the anti-proliferative defect in T cells was partially rescued by IFNAR deficiency. Sting GOF mice developed an IFN-independent SCID phenotype with a T, B and NK cell developmental defect and hypogammaglobulinemia, associated with signs of inflammation in lungs and kidneys. Only the intrinsic proliferative defect of T cells was, partially, IFN-dependent. Copyright © 2018. Published by Elsevier Inc.

Cognitive correlates of spatial navigation: Associations between executive functioning and the virtual Morris Water Task.

PubMed

Korthauer, L E; Nowak, N T; Frahmand, M; Driscoll, I

2017-01-15

Although effective spatial navigation requires memory for objects and locations, navigating a novel environment may also require considerable executive resources. The present study investigated associations between performance on the virtual Morris Water Task (vMWT), an analog version of a nonhuman spatial navigation task, and neuropsychological tests of executive functioning and spatial performance in 75 healthy young adults. More effective vMWT performance (e.g., lower latency and distance to reach hidden platform, greater distance in goal quadrant on a probe trial, fewer path intersections) was associated with better verbal fluency, set switching, response inhibition, and ability to mentally rotate objects. Findings also support a male advantage in spatial navigation, with sex moderating several associations between vMWT performance and executive abilities. Overall, we report a robust relationship between executive functioning and navigational skill, with some evidence that men and women may differentially recruit cognitive abilities when navigating a novel environment. Copyright © 2016 Elsevier B.V. All rights reserved.

An intensive virtual reality program improves functional balance and mobility of adolescents with cerebral palsy.

PubMed

Brien, Marie; Sveistrup, Heidi

2011-01-01

To examine functional balance and mobility in adolescents with cerebral palsy classified at Gross Motor Function Classification System (GMFCS) level I following an intensive short-duration virtual reality (VR) intervention. Single-subject, multiple-baseline design with 4 adolescents. Outcomes included the Community Balance and Mobility Scale (CB&M), the 6-Minute Walk Test (6MWT), the Timed Up and Down Stairs, and the Gross Motor Function Measure Dimension E. Assessments were recorded 3 to 6 times at baseline, 5 times during intervention, and 4 times at follow-up. Daily 90-minute VR intervention was completed for 5 consecutive days. Visual, statistical, and clinical significance analyses were used. Statistically significant improvements were shown in all adolescents on CB&M and 6MWT. True change was recorded in all for the CB&M and in 3 for the 6MWT. Functional balance and mobility in adolescents with cerebral palsy classified at GMFCS level I improve with intense, short duration VR intervention, and changes are maintained at 1-month posttraining.

Consolidated fuel reprocessing program

NASA Astrophysics Data System (ADS)

1985-02-01

Improved processes and components for the Breeder Reprocessing Engineering Test (BRET) were identified and developed as well as the design, procurement and development of prototypic equipment. The integrated testing of process equipment and flowsheets prototypical of a pilot scale full reprocessing plant, and also for testing prototypical remote features of specific complex components in the system are provided. Information to guide the long range activities of the Consolidated Fuel Reprocessing Program (CERP), a focal point for foreign exchange activities, and support in specialized technical areas are described. Research and development activities in HTGR fuel treatment technology are being conducted. Head-end process and laboratory scale development efforts, as well as studies specific to HTGR fuel, are reported. The development of off-gas treatment processes has generic application to fuel reprocessing, progress in this work is also reported.

Impact of Preemptive Analgesia on inflammatory responses and Rehabilitation after Primary Total Knee Arthroplasty: A Controlled Clinical Study

PubMed Central

Jianda, Xu; Yuxing, Qu; Yi, Gao; Hong, Zhao; Libo, Peng; Jianning, Zhao

2016-01-01

The aim of this study was to investigate the effects of preemptive analgesia on the inflammatory response and rehabilitation in TKA. 75 patients with unilateral primary knee osteoarthritis were conducted in this prospective study. All patients were randomly divided into two groups (MMA with/without preemptive analgesia group). The following parameters were used to evaluate analgesic efficacy: knee flexion, pain at rest and walking, functional walking capacity (2 MWT and 6 MWT), WOMAC score, and hs-CRP level. Patients in MMA with preemptive analgesia group had lower hs-CRP level and less pain at rest and walking during the first week postoperatively (P < 0.05). The 2 MWT was significantly better in MMA with preemptive analgesia group (17.13 ± 3.82 VS 14.19 ± 3.56, P = 0.001). The 6 MWT scores and WOMAC scores increased significantly within Groups (P = 0.020, 0.000), but no difference between groups postoperatively (P > 0.05). Less cumulative consumption of morphine was found in MMA with preemptive analgesia group at 48 h (P = 0.017, 0.023), but no difference at total requirement (P = 0.113). Preemptive analgesia added to a multimodal analgesic regime improved analgesia, reduced inflammatory reaction and accelerated functional recovery at the first week postoperatively, but not improved long-term function. PMID:27578313

Clinically significant change in stroke volume in pulmonary hypertension.

PubMed

van Wolferen, Serge A; van de Veerdonk, Marielle C; Mauritz, Gert-Jan; Jacobs, Wouter; Marcus, J Tim; Marques, Koen M J; Bronzwaer, Jean G F; Heymans, Martijn W; Boonstra, Anco; Postmus, Pieter E; Westerhof, Nico; Vonk Noordegraaf, Anton

2011-05-01

Stroke volume is probably the best hemodynamic parameter because it reflects therapeutic changes and contains prognostic information in pulmonary hypertension (PH). Stroke volume directly reflects right ventricular function in response to its load, without the correction of compensatory increased heart rate as is the case for cardiac output. For this reason, stroke volume, which can be measured noninvasively, is an important hemodynamic parameter to monitor during treatment. However, the extent of change in stroke volume that constitutes a clinically significant change is unknown. The aim of this study was to determine the minimal important difference (MID) in stroke volume in PH. One hundred eleven patients were evaluated at baseline and after 1 year of follow-up with a 6-min walk test (6MWT) and cardiac MRI. Using the anchor-based method with 6MWT as the anchor, and the distribution-based method, the MID of stroke volume change could be determined. After 1 year of treatment, there was, on average, a significant increase in stroke volume and 6MWT. The change in stroke volume was related to the change in 6MWT. Using the anchor-based method, an MID of 10 mL in stroke volume was calculated. The distribution-based method resulted in an MID of 8 to 12 mL. Both methods showed that a 10-mL change in stroke volume during follow-up should be considered as clinically relevant. This value can be used to interpret changes in stroke volume during clinical follow-up in PH.

Locomotor Performance During Rehabilitation of People With Lower Limb Amputation and Prosthetic Nonuse 12 Months After Discharge.

PubMed

Roffman, Caroline E; Buchanan, John; Allison, Garry T

2016-07-01

It is recognized that multifactorial assessments are needed to evaluate balance and locomotor function in people with lower limb amputation. There is no consensus on whether a single screening tool could be used to identify future issues with locomotion or prosthetic use. The purpose of this study was to determine whether different tests of locomotor performance during rehabilitation were associated with significantly greater risk of prosthetic abandonment at 12 months postdischarge. This was a retrospective cohort study. Data for descriptive variables and locomotor tests (ie, 10-Meter Walk Test [10MWT], Timed "Up & Go" Test [TUGT], Six-Minute Walk Test [6MWT], and Four Square Step Test [FSST]) were abstracted from the medical records of 201 consecutive participants with lower limb amputation. Participants were interviewed and classified as prosthetic users or nonusers at 12 months postdischarge. The Mann-Whitney U test was used to analyze whether there were differences in locomotor performance. Receiver operating characteristic curves were generated to determine performance thresholds, and relative risk (RR) was calculated for nonuse. At 12 months postdischarge, 18% (n=36) of the participants had become prosthetic nonusers. Performance thresholds, area under the curve (AUC), and RR of nonuse (95% confidence intervals [CI]) were: for the 10MWT, if walking speed was ≤0.44 ms(-1) (AUC=0.743), RR of nonuse=2.76 (95% CI=1.83, 3.79; P<.0001); for the TUGT, if time was ≥21.4 seconds (AUC=0.796), RR of nonuse=3.17 (95% CI=2.17, 4.14; P<.0001); for the 6MWT, if distance was ≤191 m (AUC=0.788), RR of nonuse=2.84, (95% CI=2.05, 3.48; P<.0001); and for the FSST, if time was ≥36.6 seconds (AUC=0.762), RR of nonuse=2.76 (95% CI=1.99, 3.39; P<.0001). Missing data, potential recall bias, and assessment times that varied were limitations of the study. Locomotor performance during rehabilitation may predict future risk of prosthetic nonuse. It may be implied that the 10MWT has the greatest clinical utility as a single screening tool for prosthetic nonuse, given the highest proportion of participants were able to perform this test early in rehabilitation. However, as locomotor skills improve, other tests (in particular, the 6MWT) have specific clinical utility. To fully enable implementation of these locomotor criteria for prosthetic nonuse into clinical practice, validation is warranted. © 2016 American Physical Therapy Association.

Integrating Nuclear Energy to Oilfield Operations – Two Case Studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eric P. Robertson; Lee O. Nelson; Michael G. McKellar

2011-11-01

Fossil fuel resources that require large energy inputs for extraction, such as the Canadian oil sands and the Green River oil shale resource in the western USA, could benefit from the use of nuclear power instead of power generated by natural gas combustion. This paper discusses the technical and economic aspects of integrating nuclear energy with oil sands operations and the development of oil shale resources. A high temperature gas reactor (HTGR) that produces heat in the form of high pressure steam (no electricity production) was selected as the nuclear power source for both fossil fuel resources. Both cases weremore » based on 50,000 bbl/day output. The oil sands case was a steam-assisted, gravity-drainage (SAGD) operation located in the Canadian oil sands belt. The oil shale development was an in-situ oil shale retorting operation located in western Colorado, USA. The technical feasibility of the integrating nuclear power was assessed. The economic feasibility of each case was evaluated using a discounted cash flow, rate of return analysis. Integrating an HTGR to both the SAGD oil sands operation and the oil shale development was found to be technically feasible for both cases. In the oil sands case, integrating an HTGR eliminated natural gas combustion and associated CO2 emissions, although there were still some emissions associated with imported electrical power. In the in situ oil shale case, integrating an HTGR reduced CO2 emissions by 88% and increased natural gas production by 100%. Economic viabilities of both nuclear integrated cases were poorer than the non-nuclear-integrated cases when CO2 emissions were not taxed. However, taxing the CO2 emissions had a significant effect on the economics of the non-nuclear base cases, bringing them in line with the economics of the nuclear-integrated cases. As we move toward limiting CO2 emissions, integrating non-CO2-emitting energy sources to the development of energy-intense fossil fuel resources is becoming increasingly important. This paper attempts to reduce the barriers that have traditionally separated fossil fuel development and application of nuclear power and to promote serious discussion of ideas about hybrid energy systems.« less

Fission product palladium-silicon carbide interaction in htgr fuel particles

NASA Astrophysics Data System (ADS)

Minato, Kazuo; Ogawa, Toru; Kashimura, Satoru; Fukuda, Kousaku; Shimizu, Michio; Tayama, Yoshinobu; Takahashi, Ishio

1990-07-01

Interaction of fission product palladium (Pd) with the silicon carbide (SiC) layer was observed in irradiated Triso-coated uranium dioxide particles for high temperature gas-cooled reactors (HTGR) with an optical microscope and electron probe microanalyzers. The SiC layers were attacked locally or the reaction product formed nodules at the attack site. Although the main element concerned with the reaction was palladium, rhodium and ruthenium were also detected at the corroded areas in some particles. Palladium was detected on both the hot and cold sides of the particles, but the corroded areas and the palladium accumulations were distributed particularly on the cold side of the particles. The observed Pd-SiC reaction depths were analyzed on the assumption that the release of palladium from the fuel kernel controls the whole Pd-SiC reaction.

Energy alternative for industry: the high-temperature gas-cooled reactor steamer

DOE Office of Scientific and Technical Information (OSTI.GOV)

McMain, A.T. Jr.; Blok, F.J.

1978-04-01

Large industrial complexes are faced with new requirements that will lead to a transition from such fluid fuels as natural gas and oil to such solid fuels as coal and uranium for supply of industrial energy. Power plants using these latter fuels will be of moderate size (800 to 1200 MW(thermal)) and will generally have the capability of co-generating electric power and process steam. A study has been made regarding use of the 840-MW(thermal) Fort St. Vrain high-temperature gas-cooled reactor (HTGR) design for industrial applications. The initial conceptual design (referred to as the HTGR Steamer) is substantially simplified relative tomore » Fort St. Vrain in that outlet helium and steam temperatures are lower and the reheat section is deleted from the steam generators. The Steamer has four independent steam generating loops producing a total of 277 kg/s (2.2 x 10/sup 6/ lb/h) of prime steam at 4.5 MPa/672 K (650 psia/750/sup 0/F). The unit co-generates 46 MW(electric) and provides process steam at 8.31 MPa/762 K(1200 psia/912/sup 0/F). The basic configuration and much of the equipment are retained from the Fort St. Vrain design. The system has inherent safety features important for industrial applications. These and other features indicate that the HTGR Steamer is an industrial energy option deserving additional evaluation. Subsequent work will focus on parallel design optimization and application studies.« less

Uranium extraction from TRISO-coated fuel particles using supercritical CO2 containing tri-n-butyl phosphate.

PubMed

Zhu, Liyang; Duan, Wuhua; Xu, Jingming; Zhu, Yongjun

2012-11-30

High-temperature gas-cooled reactors (HTGRs) are advanced nuclear systems that will receive heavy use in the future. It is important to develop spent nuclear fuel reprocessing technologies for HTGR. A new method for recovering uranium from tristructural-isotropic (TRISO-) coated fuel particles with supercritical CO(2) containing tri-n-butyl phosphate (TBP) as a complexing agent was investigated. TRISO-coated fuel particles from HTGR fuel elements were first crushed to expose UO(2) pellet fuel kernels. The crushed TRISO-coated fuel particles were then treated under O(2) stream at 750°C, resulting in a mixture of U(3)O(8) powder and SiC shells. The conversion of U(3)O(8) into solid uranyl nitrate by its reaction with liquid N(2)O(4) in the presence of a small amount of water was carried out. Complete conversion was achieved after 60 min of reaction at 80°C, whereas the SiC shells were not converted by N(2)O(4). Uranyl nitrate in the converted mixture was extracted with supercritical CO(2) containing TBP. The cumulative extraction efficiency was above 98% after 20 min of online extraction at 50°C and 25 MPa, whereas the SiC shells were not extracted by TBP. The results suggest an attractive strategy for reprocessing spent nuclear fuel from HTGR to minimize the generation of secondary radioactive waste. Copyright © 2012 Elsevier B.V. All rights reserved.

Test-retest reliability and minimal detectable change scores for the timed "up & go" test, the six-minute walk test, and gait speed in people with Alzheimer disease.

PubMed

Ries, Julie D; Echternach, John L; Nof, Leah; Gagnon Blodgett, Michelle

2009-06-01

With the increasing incidence of Alzheimer disease (AD), determining the validity and reliability of outcome measures for people with this disease is necessary. The goals of this study were to assess test-retest reliability of data for the Timed "Up & Go" Test (TUG), the Six-Minute Walk Test (6MWT), and gait speed and to calculate minimal detectable change (MDC) scores for each outcome measure. Performance differences between groups with mild to moderate AD and moderately severe to severe AD (as determined by the Functional Assessment Staging [FAST] scale) were studied. This was a prospective, nonexperimental, descriptive methodological study. Background data collected for 51 people with AD included: use of an assistive device, Mini-Mental Status Examination scores, and FAST scale scores. Each participant engaged in 2 test sessions, separated by a 30- to 60-minute rest period, which included 2 TUG trials, 1 6MWT trial, and 2 gait speed trials using a computerized gait assessment system. A specific cuing protocol was followed to achieve optimal performance during test sessions. Test-retest reliability values for the TUG, the 6MWT, and gait speed were high for all participants together and for the mild to moderate AD and moderately severe to severe AD groups separately (intraclass correlation coefficients > or = .973); however, individual variability of performance also was high. Calculated MDC scores at the 90% confidence interval were: TUG=4.09 seconds, 6MWT=33.5 m (110 ft), and gait speed=9.4 cm/s. The 2 groups were significantly different in performance of clinical tests, with the participants who were more cognitively impaired being more physically and functionally impaired. A single researcher for data collection limited sample numbers and prohibited blinding to dementia level. The TUG, the 6MWT, and gait speed are reliable outcome measures for use with people with AD, recognizing that individual variability of performance is high. Minimal detectable change scores at the 90% confidence interval can be used to assess change in performance over time and the impact of treatment.

Comparison of walking performance over the first 2 minutes and the full 6 minutes of the Six-Minute Walk Test

PubMed Central

2014-01-01

Background Although the Six-Minute Walk Test (6MWT), as recommended by the American Thoracic Society, is widely used as a measure of functional endurance, it may not be applicable in some settings and populations. We sought to examine, therefore, performance over the first 2 minutes and the full 6 minutes of the 6MWT. Specifically, we investigated completion rates, distances walked, test-retest reliability, and the relationship between distances walked over the first 2 and the full 6 minutes of the 6MWT. Methods Community-dwelling children and adults age 3–85 years (n = 337) were asked to walk back and forth on a 15.24 meter (50 ft) course as far as possible without running over a 6 minute period. Test completion and the distance covered by the participants at 2 and 6 minutes were documented. The reliability of distances covered at 2 and 6 minutes was determined by retesting a subsample of 54 participants 6 to 10 days later. The relationship between distances covered at 2 and 6 minutes was determined for the 330 participants completing the 6MWT. Results All 337 participants completed at least 2 minutes of walking, but 7 children less than 5 years of age ceased walking before 6 minutes had elapsed. For the remaining 330 participants the mean distance walked was 186 meters at 2 minutes and 543 meters at 6 minutes. The distances covered at 2 and 6 minutes were reliable between sessions (intraclass correlation coefficients = 0.888 and 0.917, respectively). The distances covered over 2 and 6 minutes were highly correlated (r = 0.968). Conclusions The completion rate, values obtained, test-retest reliability, and relationship of the distances walked in 2 and 6 minutes support documentation of 2 minute distance during the 6MWT. The findings also provide support for use of a Two-Minute Walk Test as the endurance component in the Motor Battery of the NIH Toolbox. PMID:24767634

Factors affecting mobility in community-dwelling older Koreans with chronic illnesses.

PubMed

Yeom, Hye-A; Baldwin, Carol M; Lee, Myung-Ah; Kim, Su-Jeong

2015-03-01

This descriptive study aims to describe the levels of mobility in community-dwelling older Koreans with chronic illnesses, and to examine the associations of their mobility with sleep patterns, physical activity and physical symptoms including fatigue and pain. The participants were a total of 384 community-dwelling older adults recruited from three senior centers in Seoul, Korea. Measures included mobility assessed using 6-minute walk test (6MWT), physical activity behavior, sleep profiles, fatigue and pain. Data were collected from July to December 2012. The mean 6MWT distance was 212.68 meters. Over 90% of the study participants (n = 373) were classified as having impaired mobility using 400 meters as the cutoff point diagnostic criteria of normal mobility in 6MWT. The 6MWT distance was 246.68 meters for participants in their 60s, 212.32 meters for those in their 70s, and 175.54 meters for those in their 80s. Significant predictors of mobility included younger age, taking mediation, regular physical activity, female gender, higher income, higher fatigue and better perception on sleep duration, which explained 18% of the total variance of mobility. A high-risk group for mobility limitation includes low income, sedentary older men who are at risk for increased fatigue and sleep deficit. Further research should incorporate other psychological and lifestyle factors such as depression, smoking, drinking behavior, and/or obesity into the prediction model of mobility to generate specific intervention strategies for mobility enhancement recommendations for older adults. Copyright © 2015. Published by Elsevier B.V.

Treadmill Training with Virtual Reality Improves Gait, Balance, and Muscle Strength in Children with Cerebral Palsy.

PubMed

Cho, Chunhee; Hwang, Wonjeong; Hwang, Sujin; Chung, Yijung

2016-03-01

Independent walking is an important goal of clinical and community-based rehabilitation for children with cerebral palsy (CP). Virtual reality-based rehabilitation therapy is effective in motivating children with CP. This study investigated the effects of treadmill training with virtual reality on gait, balance, muscular strength, and gross motor function in children with CP. Eighteen children with spastic CP were randomly divided into the virtual reality treadmill training (VRTT) group (9 subjects, mean age, 10.2 years) and treadmill training (TT) group (9 subjects, mean age, 9.4 years). The groups performed their respective programs as well as conventional physical therapy 3 times/week for 8 weeks. Muscle strength was assessed using a digitalized manual muscle tester. Gross motor function was assessed using the Gross Motor Functional Measure (GMFM). Balance was assessed using the Pediatric Balance Scale (PBS). Gait speed was assessed using the 10-meter walk test (10MWT), and gait endurance was assessed using the 2-minute walk test (2MWT). After training, gait and balance was improved in the VRTT compared to the TT group (P < 0.05). Muscular strength was significantly greater in the VRTT group than the TT group, except for right hamstring strength. The improvements in GMFM (standing) and PBS scores were greater in the VRTT group than the TT group (P < 0.05). Furthermore, the VRTT group showed the higher values of 10MWT and 2MWT compared to the TT group (P < 0.05). In conclusion, VRTT programs are effective for improving gait, balance, muscular strength, and gross motor function in children with CP.

The effectiveness of body weight-supported gait training and floor walking in patients with chronic stroke.

PubMed

Peurala, Sinikka H; Tarkka, Ina M; Pitkänen, Kauko; Sivenius, Juhani

2005-08-01

To compare body weight-supported exercise on a gait trainer with walking exercise overground. Randomized controlled trial. Rehabilitation hospital. Forty-five ambulatory patients with chronic stroke. Patients were randomized to 3 groups: (1) gait trainer exercise with functional electric stimulation (GTstim), (2) gait trainer exercise without stimulation (GT), and (3) walking overground (WALK). All patients practiced gait for 15 sessions during 3 weeks (each session, 20 min), and they received additional physiotherapy 55 minutes daily. Ten-meter walk test (10MWT), six-minute walk test (6MWT), lower-limb spasticity and muscle force, postural sway tests, Modified Motor Assessment Scale (MMAS), and FIM instrument scores were recorded before, during, and after the rehabilitation and at 6 months follow-up. The mean walking distance using the gait trainer was 6900+/-1200 m in the GTstim group and 6500+/-1700 m in GT group. In the WALK group, the distance was 4800+/-2800 m, which was less than the walking distance obtained in the GTstim group (P=.027). The body-weight support was individually reduced from 30% to 9% of the body weight over the course of the program. In the pooled 45 patients, the 10MWT (P<.001), 6MWT (P<.001), MMAS (P<.001), dynamic balance test time (P<.001), and test trip (P=.005) scores improved; however, no differences were found between the groups. Both the body weight-supported training and walking exercise training programs resulted in faster gait after the intensive rehabilitation program. Patients' motor performance remained improved at the follow-up.

Individualized treadmill and strength training for chronic stroke rehabilitation: effects of imbalance.

PubMed

Al-Jarrah, Muhammed; Shaheen, Samira; Harries, Netta; Kissani, Najib; Molteni, Franco; Bar Haim, Simona

2014-01-01

Stroke survivors often have significant walking limitations and are at high risk for falling. Treadmill training, as a rehabilitation approach in stroke survivors, and its relationship to balance ability has not been widely studied. The main goal of this study was to investigate the effectiveness of an individualized treadmill-strength training protocol on functional outcomes in chronic stroke survivors. Thirty adult participants with chronic stroke were recruited from 1 European and 4 Middle Eastern countries. Each completed 36 sessions of treadmill-strength training. The rehabilitation protocol was individualized according to each patient's cardiovascular fitness. Ten-meter walk test (10MWT), Berg Balance Scale (BBS), and 6-minute walk test (6MWT) were measured before (T0) and after training (T1) and 6 months later (T2). Paired t tests were used to test differences with training (T1 - T0) and retention after training (T2 - T1). Increases in all 3 measures from T0 to T1 were significant. There were no changes in 10MWT and BBS from T1 to T2, but 6MWT tended to increase. Separate analyses for subjects with BBS scores <41 at T0 demonstrated comparatively greater improvements from T0 to T1 than in those with BBS scores ≯40. Those with low scores also significantly increased from T1 to T2 in both walk tests. These findings suggest that a protocol combining treadmill with strength training has beneficial long-term effects on functional walking measures after chronic stroke, especially in patients who initially have low balance ability.

Effects of kinesiotherapy, ultrasound and electrotherapy in management of bilateral knee osteoarthritis: prospective clinical trial

PubMed Central

2012-01-01

Background Although recent advances in knee osteoarthritis (OA) treatment and evaluation were achieved, to the best of our knowledge, few studies have evaluated the longitudinal effect of therapeutic modalities on the functional exercise capacity of patients with knee OA. The purpose was to investigate the effects of kinesiotherapy and electrotherapy on functional exercise capacity, evaluated using the six-minute walk test (6-MWT) in patients with bilateral knee OA. Secondary measurements included range of motion (ROM), severity of knee pain (VAS), and a measure of perceived health and physical function, evaluated using the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index. Methods A total of 40 women with bilateral knee OA were assigned to three groups: kinesiotherapy (KIN, n = 16), transcutaneous electrical nerve stimulation (TENS, n = 12), or ultrasound (US, n = 10). The groups underwent 12 weeks of intervention twice per week. The participants were subjected to the 6-MWT, ROM, VAS and WOMAC index. These tests were performed before and after the intervention. The study was focused on outpatients and was carried out at Universidade Estadual de Campinas, Brazil. Results At follow-up, the KIN and US groups had significantly higher 6-MWT distances (19.8 ± 21.7 and 14.1 ± 22.5%, respectively) compared with their respective pre-intervention values. All treatments were effective for reducing pain and improving the WOMAC index. Conclusions We demonstrated that the 6-MWT is a tool that can be used to evaluate improvements in the functional exercise capacity of patients submitted to a clinical intervention. PMID:22999098

Effects of kinesiotherapy, ultrasound and electrotherapy in management of bilateral knee osteoarthritis: prospective clinical trial.

PubMed

Mascarin, Naryana Cristina; Vancini, Rodrigo Luiz; Andrade, Marã Lia Dos Santos; Magalhães, Eduardo de Paiva; de Lira, Claudio Andre Barbosa; Coimbra, Ibsen Bellini

2012-09-22

Although recent advances in knee osteoarthritis (OA) treatment and evaluation were achieved, to the best of our knowledge, few studies have evaluated the longitudinal effect of therapeutic modalities on the functional exercise capacity of patients with knee OA. The purpose was to investigate the effects of kinesiotherapy and electrotherapy on functional exercise capacity, evaluated using the six-minute walk test (6-MWT) in patients with bilateral knee OA. Secondary measurements included range of motion (ROM), severity of knee pain (VAS), and a measure of perceived health and physical function, evaluated using the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index. A total of 40 women with bilateral knee OA were assigned to three groups: kinesiotherapy (KIN, n = 16), transcutaneous electrical nerve stimulation (TENS, n = 12), or ultrasound (US, n = 10). The groups underwent 12 weeks of intervention twice per week. The participants were subjected to the 6-MWT, ROM, VAS and WOMAC index. These tests were performed before and after the intervention. The study was focused on outpatients and was carried out at Universidade Estadual de Campinas, Brazil. At follow-up, the KIN and US groups had significantly higher 6-MWT distances (19.8 ± 21.7 and 14.1 ± 22.5%, respectively) compared with their respective pre-intervention values. All treatments were effective for reducing pain and improving the WOMAC index. We demonstrated that the 6-MWT is a tool that can be used to evaluate improvements in the functional exercise capacity of patients submitted to a clinical intervention.

Heart Rate Recovery in the First Minute at the Six-Minute Walk Test in Patients with Heart Failure

PubMed Central

Lindemberg, Sabrina; Chermont, Sergio; Quintão, Mônica; Derossi, Milena; Guilhon, Sergio; Bernardez, Sabrina; Marchese, Luana; Martins, Wolney; Nóbrega, Antônio Claudio L.; Mesquita, Evandro Tinoco

2014-01-01

Background Heart rate recovery at one minute of rest (HRR1) is a predictor of mortality in heart failure (HF), but its prognosis has not been assessed at six-minute walk test (6MWT) in these patients. Objective This study aimed to determine the HRR1 at 6MWT in patients with HF and its correlation with six-minute walk distance (6MWD). Methods Cross-sectional, controlled protocol with 161 individuals, 126 patients with stable systolic HF, allocated into 2 groups (G1 and G2) receiving or not β-blocker and 35 volunteers in control group (G3) had HRR1 recorded at the 6MWT. Results HRR1 and 6MWD were significantly different in the 3 groups. Mean values of HRR1 and 6MWD were: HRR1 = 12 ± 14 beat/min G1; 18 ± 16 beat/min G2 and 21 ± 13 beat/min G3; 6MWD = 423 ± 102 m G1; 396 ± 101m G2 and 484 ± 96 m G3 (p < 0.05). Results showed a correlation between HRR1 and 6MWD in G1(r = 0.3; p = 0.04) and in G3(r = 0.4; p= 0.03), but not in G2 (r= 0.12; p= 0.48). Conclusion HRR1 response was attenuated in patients using βB and showed correlation with 6MWD, reflecting better exercise tolerance. HRR1 after 6MWT seems to represent an alternative when treadmill tests could not be tolerated. PMID:24714794

Effect of Pulsed Radiofrequency on Rat Sciatic Nerve Chronic Constriction Injury: A Preliminary Study

PubMed Central

Li, Duo-Yi; Meng, Lan; Ji, Nan; Luo, Fang

2015-01-01

Background: Pulsed radiofrequency (PRF) application to the dorsal root ganglia can reduce neuropathic pain (NP) in animal models, but the effect of PRF on damaged peripheral nerves has not been examined. We investigated the effect of PRF to the rat sciatic nerve (SN) on pain-related behavior and SN ultrastructure following chronic constriction injury (CCI). Methods: The analgesic effect was measured by hindpaw mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL). Twenty rats with NP induced by ligating the common SN were then randomly divided into a PRF treatment group and a sham group. The contralateral SN served as a control. The MWT and TWL were determined again 2, 4, 6, 8, 10, 12, and 14 days after the PRF or sham treatment. On day 14, ipsilateral and contralateral common SNs were excised and examined by electron microscopy. Results: Ipsilateral MWT was significantly reduced and TWL significantly shorter compared to the contralateral side 14 days after CCI (both P = 0.000). In the PRF group, MWT was significantly higher and TWL significantly longer 14 days after the PRF treatment compared to before PRF treatment (both P = 0.000), while no such difference was observed in the sham group (P > 0.05). Electron microscopy revealed extensive demyelination and collagen fiber formation in the ipsilateral SN of sham-treated rats but sparse demyelination and some nerve fiber regrowth in the PRF treatment group. Conclusions: Hyperalgesia is relieved, and ultrastructural damage ameliorated after direct PRF treatment to the SN in the CCI rat model of NP. PMID:25673460

Hybrid Assistive Limb Exoskeleton HAL in the Rehabilitation of Chronic Spinal Cord Injury: Proof of Concept; the Results in 21 Patients.

PubMed

Jansen, Oliver; Grasmuecke, Dennis; Meindl, Renate C; Tegenthoff, Martin; Schwenkreis, Peter; Sczesny-Kaiser, Matthias; Wessling, Martin; Schildhauer, Thomas A; Fisahn, Christian; Aach, Mirko

2018-02-01

The use of mobile exoskeletons is becoming more and more common in the field of spinal cord injury (SCI) rehabilitation. The hybrid assistive limb (HAL) exoskeleton provides a tailored support depending on the patient's voluntary drive. After a pilot study in 2014 that included 8 patients with chronic SCI, this study of 21 patients with chronic SCI serves as a proof of concept. It was conducted to provide further evidence regarding the efficacy of exoskeletal-based rehabilitation. Functional assessment included walking speed, distance, and time on a treadmill, with additional analysis of functional mobility using the following tests: 10-meter walk test (10MWT), timed up and go (TUG) test, 6-minute walk test (6MWT), and the walking index for SCI II (WISCI-II) score. After a training period of 90 days, all 21 patients significantly improved their functional and ambulatory mobility without the exoskeleton. Patients were assessed by the 6MWT, the TUG test, and the 10MWT, which also indicated an increase in the WISCI-II score along with significant improvements in HAL-associated walking speed, distance, and time. Although, exoskeletons are not yet an established treatment in the rehabilitation of spinal cord injuries, the devices will play a more important role in the future. The HAL exoskeleton training enables effective, body weight-supported treadmill training and is capable of improving ambulatory mobility. Future controlled studies are required to enable a comparison of the new advances in the field of SCI rehabilitation with traditional over-ground training. Copyright © 2017 Elsevier Inc. All rights reserved.

Lung function, functional capacity, and respiratory symptoms at discharge from hospital in patients with acute pulmonary embolism: A cross-sectional study.

PubMed

Danielsbacka, Jenny S; Olsén, Monika Fagevik; Hansson, Per-Olof; Mannerkorpi, Kaisa

2018-03-01

Acute pulmonary embolism (PE) is a cardiovascular disease with symptoms including respiratory associated chest pain (RACP) and dyspnea. No previous studies exist focusing on lung function, functional capacity, and respiratory symptoms at discharge after PE. The aim was to examine and describe lung function, functional capacity, and respiratory symptoms at discharge in patients with PE and compare to reference values. Fifty consecutive patients with PE admitted to the Acute Medical Unit, Sahlgrenska University Hospital, were included. Size of PE was calculated by Qanadli score (QS) percentage (mean QS 33.4% (17.6)). FVC and FEV 1 were registered and 6-minute walk test (6MWT) performed at the day of discharge. RACP was rated before and after spirometry/6MWT with the Visual Analogue Scale. Perceived exertion was rated with Borg CR-10 scale. Spirometry and 6MWT results were compared with reference values. This study shows that patients with PE have significantly reduced lung function (p < 0.05) and functional capacity (p < 0.001) at discharge compared with reference values. Patients with higher QS percentage were more dyspneic after 6MWT, no other significant differences in lung function or functional capacity were found between the groups. The patients still suffer from RACP (30%) and dyspnea (60%) at discharge. This study indicates that patients with PE have a reduced lung function, reduced functional capacity, and experience respiratory symptoms as pain and dyspnea at discharge. Further studies are needed concerning long-term follow-up of lung function, functional capacity, and symptoms after PE.

Listening to motivational music while walking elicits more positive affective response in patients with cystic fibrosis.

PubMed

Calik-Kutukcu, Ebru; Saglam, Melda; Vardar-Yagli, Naciye; Cakmak, Aslihan; Inal-Ince, Deniz; Bozdemir-Ozel, Cemile; Sonbahar-Ulu, Hazal; Arikan, Hulya; Yalcin, Ebru; Karakaya, Jale

2016-05-01

The purpose of this study was to investigate the effects of motivational and relaxation music on affective responses during exercise in patients with cystic fibrosis (CF). Thirty-seven patients with CF performed the 6-min walk test (6MWT) under three experimental conditions: listening to no music, relaxation music, and motivational music. 6-min distance × body weight product (6MWORK) was calculated for each trial. Patients' affective responses during exercise was evaluated with Feeling Scale (FS). The motivational qualities of music were evaluated with the Brunel Music Rating Inventory-2 (BMRI-2). 6MWORK was significantly lower while listening to relaxation music compared to 6MWORK without music (p < 0.05). FS and BMRI-2 scores were significantly higher during 6MWT with motivational music than 6MWT with relaxation music (p < 0.05). Carefully selected motivational music can lead to positive affective response during exercise and increase the enjoyment of patients from exercises in CF. Copyright © 2016 Elsevier Ltd. All rights reserved.

Longitudinal timed function tests in Duchenne muscular dystrophy: ImagingDMD cohort natural history.

PubMed

Arora, Harneet; Willcocks, Rebecca J; Lott, Donovan J; Harrington, Ann T; Senesac, Claudia R; Zilke, Kirsten L; Daniels, Michael J; Xu, Dandan; Tennekoon, Gihan I; Finanger, Erika L; Russman, Barry S; Finkel, Richard S; Triplett, William T; Byrne, Barry J; Walter, Glenn A; Sweeney, H Lee; Vandenborne, Krista

2018-05-09

Tests of ambulatory function are common clinical trial endpoints in Duchenne muscular dystrophy (DMD). The ImagingDMD study has generated a large data set using these tests, which can describe the contemporary natural history of DMD in 5-12.9 year olds. 92 corticosteroid treated boys with DMD and 45 controls participated in this longitudinal study. Subjects performed the 6 minute walk test (6MWT) and timed function tests (TFTs: 10m walk/run, 4 stairs, supine to stand). Boys with DMD had impaired functional performance even at 5-6.9 years. Boys older than 7 had significant declines in function over 1 year for 10m walk/run and 6MWT. 80% of subjects could perform all functional tests at 9 years old. TFTs appear to be slightly more responsive and predictive of disease progression than 6MWT in 7-12.9 year olds. This study provides insight into the contemporary natural history of key functional endpoints in DMD. This article is protected by copyright. All rights reserved. © 2018 Wiley Periodicals, Inc.

Thermal-Hydraulic Design of a Fluoride High-Temperature Demonstration Reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carbajo, Juan J; Qualls, A L

2016-01-01

INTRODUCTION The Fluoride High-Temperature Reactor (FHR) named the Demonstration Reactor (DR) is a novel reactor concept using molten salt coolant and TRIstructural ISOtropic (TRISO) fuel that is being developed at Oak Ridge National Laboratory (ORNL). The objective of the FHR DR is to advance the technology readiness level of FHRs. The FHR DR will demonstrate technologies needed to close remaining gaps to commercial viability. The FHR DR has a thermal power of 100 MWt, very similar to the SmAHTR, another FHR ORNL concept (Refs. 1 and 2) with a power of 125 MWt. The FHR DR is also a smallmore » version of the Advanced High Temperature Reactor (AHTR), with a power of 3400 MWt, cooled by a molten salt and also being developed at ORNL (Ref. 3). The FHR DR combines three existing technologies: (1) high-temperature, low-pressure molten salt coolant, (2) high-temperature coated-particle TRISO fuel, (3) and passive decay heat cooling systems by using Direct Reactor Auxiliary Cooling Systems (DRACS). This paper presents FHR DR thermal-hydraulic design calculations.« less

Imaging wet granules with different flow patterns by electrical capacitance tomography and microwave tomography

NASA Astrophysics Data System (ADS)

Wang, H. G.; Zhang, J. L.; Ramli, M. F.; Mao, M. X.; Ye, J. M.; Yang, W. Q.; Wu, Z. P.

2016-11-01

The moisture content of granules in fluidised bed drying, granulation and coating processes can typically be between 1%~25%, resulting in the change of permittivity and conductivity during the processes. Electrical capacitance tomography (ECT) has been used for this purpose, but has a limit because too much water can cause a problem in capacitance measurement. Considering that microwave tomography (MWT) has a wide range of frequency (1~2.5 GHz) and can be used to measure materials with high permittivity and conductivity, the objective of this research is to combine ECT and MWT together to investigate the solids concentration with different moisture content and different flow patterns. The measurement results show that both ECT and MWT are functions of moisture content as well as flow patterns, and their measurements are complementary to each other. This is the first time that these two tomography modalities have been combined together and applied to image the complex solids distribution. The obtained information may be used for the process control of fluidised bed drying, granulation and coating to improve operation efficiency.

NRC ARDC Guidance Support Status Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holbrook, Mark R.

This report provides a summary that reflects the progress and status of proposed regulatory design criteria for advanced non-light water reactor (LWR) designs in accordance with the Level 3 milestone M3AT-17IN2001013 in work package AT-17IN200101. These criteria have been designated as advanced reactor design criteria (ARDC) and they provide guidance to future applicants for addressing the general design criteria (GDC) that are currently applied specifically to LWR designs. This report provides a summary of Phase 2 activities related to the various tasks associated with ARDC development and the subsequent development of ARDC regulatory guidance for sodium fast reactor (SFR) andmore » modular high-temperature gas-cooled reactor (HTGR) designs. Status Report Organization: Section 2 discusses the origin of the GDC and their application to LWRs. Section 3 addresses the objective of this initiative and how it benefits the advanced non-LWR reactor vendors. Section 4 discusses the scope and structure of the initiative. Section 5 provides background on the U.S. Department of Energy (DOE) ARDC team’s original development of the proposed ARDC that were submitted to the NRC for consideration. Section 6 provides a summary of recent ARDC Phase 2 activities. Appendices A through E document the DOE ARDC team’s public comments on various sections of the NRC’s draft regulatory guide DG–1330, “Guidance for Developing Principal Design Criteria for Non-Light Water Reactors.”« less

Analyzing the impact of reactive transport on the repository performance of TRISO fuel

NASA Astrophysics Data System (ADS)

Schmidt, Gregory

One of the largest determiners of the amount of electricity generated by current nuclear reactors is the efficiency of the thermodynamic cycle used for power generation. Current light water reactors (LWR) have an efficiency of 35% or less for the conversion of heat energy generated by the reactor to electrical energy. If this efficiency could be improved, more power could be generated from equivalent volumes of nuclear fuel. One method of improving this efficiency is to use a coolant flow that operates at a much higher temperature for electricity production. A reactor design that is currently proposed to take advantage of this efficiency is a graphite-moderated, helium-cooled reactor known as a High Temperature Gas Reactor (HTGR). There are significant differences between current LWR's and the proposed HTGR's but most especially in the composition of the nuclear fuel. For LWR's, the fuel elements consist of pellets of uranium dioxide or plutonium dioxide that are placed in long tubes made of zirconium metal alloys. For HTGR's, the fuel, known as TRISO (TRIstructural-ISOtropic) fuel, consists of an inner sphere of fissile material, a layer of dense pyrolytic carbon (PyC), a ceramic layer of silicon carbide (SiC) and a final dense outer layer of PyC. These TRISO particles are then compacted with graphite into fuel rods that are then placed in channels in graphite blocks. The blocks are then arranged in an annular fashion to form a reactor core. However, this new fuel form has unanswered questions on the environmental post-burn-up behavior. The key question for current once-through fuel operations is how these large irradiated graphite blocks with spent fuel inside will behave in a repository environment. Data in the literature to answer this question is lacking, but nevertheless this is an important question that must be answered before wide-spread adoption of HTGR's could be considered. This research has focused on answering the question of how the large quantity of graphite surrounding the spent HTGR fuel will impact the release of aqueous uranium from the TRISO fuel. In order to answer this question, the sorption and partitioning behavior of uranium to graphite under a variety of conditions was investigated. Key systematic variables that were analyzed include solution pH, dissolved carbonate concentration, uranium metal concentration and ionic strength. The kinetics and desorption characteristics of uranium/graphite partitioning were studied as well. The graphite used in these experiments was also characterized by a variety of techniques and conclusions are drawn about the relevant surface chemistry of graphite. This data was then used to generate a model for the reactive transport of uranium in a graphite matrix. This model was implemented with the software code CXTFIT and validated through the use of column studies mirroring the predicted system.

Irradiation performance of HTGR recycle fissile fuel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Homan, F.J.; Long, E.L. Jr.

1976-08-01

The irradiation performance of candidate HTGR recycle fissile fuel under accelerated testing conditions is reviewed. Failure modes for coated-particle fuels are described, and the performance of candidate recycle fissile fuels is discussed in terms of these failure modes. The bases on which UO/sub 2/ and (Th,U)O/sub 2/ were rejected as candidate recycle fissile fuels are outlined, along with the bases on which the weak-acid resin (WAR)-derived fissile fuel was selected as the reference recycle kernel. Comparisons are made relative to the irradiation behavior of WAR-derived fuels of varying stoichiometry and conclusions are drawn about the optimum stoichiometry and the rangemore » of acceptable values. Plans for future testing in support of specification development, confirmation of the results of accelerated testing by real-time experiments, and improvement in fuel performance and reliability are described.« less

A Comparison of Objective Physical Performance Tests and Future Mortality in the Elderly People.

PubMed

Veronese, Nicola; Stubbs, Brendon; Fontana, Luigi; Trevisan, Caterina; Bolzetta, Francesco; Rui, Marina De; Sartori, Leonardo; Musacchio, Estella; Zambon, Sabina; Maggi, Stefania; Perissinotto, Egle; Corti, Maria Chiara; Crepaldi, Gaetano; Manzato, Enzo; Sergi, Giuseppe

2017-03-01

Physical performance is an important predictor of mortality, but little is known on the comparative prognostic utility of different objective physical performance tests in community-dwelling older adults. We compared the prognostic usefulness of several objective physical performance tests on mortality, adjusting our analyses for potential confounders. Among 3,099 older community-dwelling participants included in the Progetto Veneto Anziani study, 2,096 were followed for a mean of 4.4 years. Physical performance tests measured were Short Physical Performance Battery (SPPB), 4-meter gait speed, chair stands time, leg extension and flexion, handgrip strength, and 6-Minute Walking Test (6MWT), treated as continuous variables and categorized in gender-specific quartiles. The main outcome was mortality assessed with death certificates. Participants who died during the follow-up (n = 327) scored significantly worse in all physical performance tests measured at baseline than those who survived (n = 1,769). Using a Harrell's C-index, the highest C-index was observed for 6MWT in men (C-index = 0.735; 95% confidence interval [CI]: 0.701-0.770, p < .0001) and SPPB in women (C-index = 0.781; 95% CI: 0.740-0.822, p = .0009). However, in both genders, only SPPB, 4-meter walking speed, and 6MWT are significant predictors of mortality. Analyses using sex-specific quartiles substantially confirmed these findings. Slow gait speed, 6MWT, and SPPB are significant predictors for mortality in community-dwelling older men and women. Physicians should consider using these tests to identify elderly individuals who are at higher risk of death to improve clinical decision making. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Health-related fitness in very long-term survivors of childhood cancer: A cross-sectional study.

PubMed

Hartman, Annelies; Pluijm, Saskia M F; Wijnen, Mark; Neggers, Sebastian J C M M; Clemens, Eva; Pieters, Rob; van den Heuvel-Eibrink, Marry M

2018-04-01

Impairment of health-related physical fitness (HRPF) in survivors of acute lymphoblastic leukemia has been shown. However, evidence of impairment in survivors of other pediatric malignancies and possible risk factors is limited. HRPF of 17 survivors of pediatric acute myeloid leukemia (AML), 26 survivors of neuroblastoma (NBL), 28 survivors of Wilms tumor (WT) (median age 28.8 [18.8-62.6] years) after a median follow-up time of 24.5 (6.5-43.6) years, and 74 healthy controls (median age 26.9 [17.9-61.7] years). Risk factors were investigated. Testing included submaximal cardiovascular endurance (6-Minute Walk Test (6 MWT), flexibility, and muscle strength. Results are expressed as mean (standard error). Survivors scored significantly lower than controls on the 6 MWT (588 ± 6.1 m vs. controls 611 ± 6.0 m; P = 0.008), on side flexion of the trunk (20.1 ± 0.4 cm vs. controls 22.4 ±0.4 cm; P < 0.001), and on vertical jump (39.7 ± 0.8 cm vs. controls 43.8 ± 0.8 cm; P < 0.001). Survivors of AML had lower scores on the 6 MWT (563 ± 12.4 m) than survivors of NBL (585 ± 9.9 m) and survivors of WT (606 ± 9.6 m), P = 0.046. Being a survivor, higher body mass index (BMI) and no participation in sports were independently associated with lower scores on the 6 MWT. Survivors of NBL, WT, and especially AML have impaired HRPF. Higher BMI and physical inactivity at adult age appeared prominent risk factors for impaired HRPF in these survivors. © 2017 Wiley Periodicals, Inc.

Using the Human Activity Profile to Assess Functional Performance in Heart Failure.

PubMed

Ribeiro-Samora, Giane Amorim; Pereira, Danielle Aparecida Gomes; Vieira, Otávia Alves; de Alencar, Maria Clara Noman; Rodrigues, Roseane Santo; Carvalho, Maria Luiza Vieira; Montemezzo, Dayane; Britto, Raquel Rodrigues

2016-01-01

To investigate (1) the validity of using the Human Activity Profile (HAP) in patients with heart failure (HF) to estimate functional capacity; (2) the association between the HAP and 6-Minute Walk Test (6MWT) distance; and (3) the ability of the HAP to differentiate between New York Heart Association (NYHA) functional classes. In a cross-sectional study, we evaluated 62 clinically stable patients with HF (mean age, 47.98 years; NYHA class I-III). Variables included maximal functional capacity as measured by peak oxygen uptake ((Equation is included in full-text article.)O2) using a cardiopulmonary exercise test (CPET), peak (Equation is included in full-text article.)O2 as estimated by the HAP, and exercise capacity as measured by the 6MWT. The difference between the measured (CPET) and estimated (HAP) peak (Equation is included in full-text article.)O2 against the average values showed a bias of 2.18 mL/kg/min (P = .007). No agreement was seen between these measures when applying the Bland-Altman method. Peak (Equation is included in full-text article.)O2 in the HAP showed a moderate association with the 6MWT distance (r = 0.62; P < .0001). Peak (Equation is included in full-text article.)O2 in the HAP was able to statistically differentiate NYHA functional classes I, II, and III (P < .05). The estimated peak (Equation is included in full-text article.)O2 using the HAP was not concordant with the gold standard CPET measure. On the contrary, the HAP was able to differentiate NYHA functional class associated with the 6MWT distance; therefore, the HAP is a useful tool for assessing functional performance in patients with HF.

Role of the cardio-pulmonary exercise test and six-minute walking test in the evaluation of exercise performance in patients with late-onset Pompe disease.

PubMed

Crescimanno, G; Modica, R; Lo Mauro, R; Musumeci, O; Toscano, A; Marrone, O

2015-07-01

In patients with late-onset Pompe disease, we explored the role of the Cardiopulmonary Exercise Test (CPET) and the Six-Minute Walking Test (6MWT) in the assessment of exercise capacity and in the evaluation of the effects of enzyme replacement therapy (ERT). Eight patients affected by late-onset Pompe disease, followed up at the Centre for Neuromuscular Diseases and treated with ERT, underwent a baseline evaluation with a spirometry, a CPET and a 6MWT. Four of them were restudied after 36 months of treatment. Three patients showed a reduction in exercise capacity as evaluated by peak oxygen uptake (VO2) measured at the CPET and Distance Walked (DW) measured at the 6MWT (median % predicted: 67.1 [range 54.3-99.6] and 67.3 [56.6-82.6], respectively). Cardiac and respiratory limitations revealed by the CPET were correlated to peak VO2, but not to the DW. Nevertheless, percent of predicted values of peak VO2 and DW were strongly correlated (rho = 0.85, p = 0.006), and close to identity. In the longitudinal evaluation forced vital capacity decreased, while peak VO2 and DW showed a trend to a parallel improvement. We concluded that although only the CPET revealed causes of exercise limitation, which partially differed among patients, CPET and 6MWT showed a similar overall degree of exercise impairment. That held true in the longitudinal assessment during ERT, where both tests demonstrated similar small improvements, occurring despite deterioration in forced vital capacity. Copyright © 2015 Elsevier B.V. All rights reserved.

Noninvasive Assessment of Neuromuscular Disease in Dogs: Use of the 6-minute Walk Test to Assess Submaximal Exercise Tolerance in Dogs with Centronuclear Myopathy.

PubMed

Cerda-Gonzalez, S; Talarico, L; Todhunter, R

2016-05-01

Noninvasive methods of quantitating exercise tolerance in dogs with neuromuscular disease are needed both for clinical and research use. The 6-minute walk test (6MWT) has been validated as a reliable test of exercise tolerance in dogs with pulmonary and cardiac disease, but not in dogs with neuromuscular disease. Distance walked and number of steps taken during 6MWT will differ between Labrador retriever dogs with centronuclear myopathy (CNM) and control (ie, healthy) littermates. Eight purebred Labrador retrievers were drawn from a purpose-bred research colony (status: 3 clear, 2 carrier, and 3 homozygous mutants for the protein tyrosine phosphatase-like A (PTPLA) gene mutation associated with CNM). Pilot, prospective, Case-controlled study. Researchers were blinded to disease status. Each dog was leash-trained and acclimatized to the testing area (length, 12.8 m). At the start of testing, each animal was fitted with a pedometer, a timer was started, and dogs were allowed to walk at their own pace for 6 minutes. Distance walked and pedometer readings were recorded. Degree of paresis varied among affected dogs, and was reflected by significant differences in distance walked between CNM-affected dogs and those with clear and carrier genotypes (P = .048). Pedometer readings did not vary according to genotype (P = .86). The 6MWT appears to differentiate between the ambulatory capacity of normal and CNM-affected dogs. Additional studies are needed to confirm this relationship in a larger number of dogs, and to evaluate the ability of the 6MWT to differentiate between dogs with variable severity of neuromuscular disease-associated exercise intolerance. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Rubus occidentalis alleviates hyperalgesia induced by repeated intramuscular injection of acidic saline in rats.

PubMed

Choi, Geun Joo; Kang, Hyun; Kim, Won Joong; Baek, Chong Wha; Jung, Yong Hun; Woo, Young Cheol; Kwon, Ji Wung

2016-07-11

The purpose of this study was to evaluate the antinociceptive effect of black raspberry (Rubus occidentalis) fruit extract (ROE) in a rat model of chronic muscle pain and examine the mechanisms involved. Adult male Sprague-Dawley rats were used, and chronic muscle pain was induced by two injections of acidic saline into one gastrocnemius muscle. For the first experiment, 50 rats were randomly assigned to five groups. After the development of hyperalgesia, rats were injected intraperitoneally with 0.9 % saline or ROE (10, 30, 100, or 300 mg/kg). For the second experiment, 70 rats were randomly assigned to seven groups. Rats were injected intraperitoneally with saline, yohimbine, dexmedetomidine, prazosin, atropine, mecamylamine, or naloxone after the development of hyperalgesia. Ten minutes later, ROE (300 mg/kg) was administered intraperitoneally. For both experiments, the mechanical withdrawal threshold (MWT) was evaluated with von Frey filaments before the first acidic saline injection, 24 h after the second injection, and at 15, 30, 45, 60, 80, 100, and 120 min, 24 and 48 h after the drug administration. Compared with the control group, the MWT significantly increased up to 45 min after injection of ROE 100 mg/kg and up to 60 min after injection of ROE 300 mg/kg, respectively. Injection of ROE together with yohimbine or mecamylamine significantly decreased the MWT compared with the effect of ROE alone, while ROE together with dexmedetomidine significantly increased the MWT. ROE showed antinociceptive activity against induced chronic muscle pain, which may be mediated by α2-adrenergic and nicotinic cholinergic receptors.

Transvertebral direct current stimulation paired with locomotor training in chronic spinal cord injury: A case study.

PubMed

Powell, Elizabeth Salmon; Carrico, Cheryl; Raithatha, Ravi; Salyers, Emily; Ward, Andrea; Sawaki, Lumy

2016-01-01

This double-blind, sham-controlled, crossover case study combined transvertebral direct current stimulation (tvDCS) and locomotor training on a robot-assisted gait orthosis (LT-RGO). Determine whether cathodal tvDCS paired with LT-RGO leads to greater changes in function and neuroplasticity than sham tvDCS paired with LT-RGO. University of Kentucky (UK) HealthCare Stroke and Spinal Cord Neurorehabilitation Research at HealthSouth Cardinal Hill Hospital. A single subject with motor incomplete spinal cord injury (SCI) participated in 24 sessions of sham tvDCS paired with LT-RGO before crossover to 24 sessions of cathodal tvDCS paired with LT-RGO. Functional outcomes were measured with 10 Meter Walk Test (10MWT), 6 Minute Walk Test (6MWT), Spinal Cord Independence Measure-III (SCIM-III) mobility component, lower extremity manual muscle test (MMT), and Berg Balance Scale (BBS). Corticospinal changes were assessed using transcranial magnetic stimulation. Improvement in 10MWT speed, SCIM-III mobility component, and BBS occurred with both conditions. 6MWT worsened after sham tvDCS and improved after cathodal tvDCS. MMT scores for both lower extremities improved following sham tvDCS but decreased following cathodal tvDCS. Corticospinal excitability increased following cathodal tvDCS but not sham tvDCS. These results suggest that combining cathodal tvDCS and LT-RGO may improve functional outcomes, increase corticospinal excitability, and possibly decrease spasticity. Randomized controlled trials are needed to confirm these conclusions. This publication was supported by the National Center for Research Resources and the National Center for Advancing Translational Sciences, National Institutes of Health, through Grant UL1TR000117, and the HealthSouth Cardinal Hill Stroke and Spinal Cord Endowment (1215375670).

Predictors of dynamic hyperinflation during the 6-minute walk test in stable chronic obstructive pulmonary disease patients

PubMed Central

Chen, Rui; Lin, Lin; Tian, Jing-Wei; Zeng, Bin; Zhang, Lei

2015-01-01

Background Dynamic hyperinflation (DH) is a major contributor to exercise limitation in chronic obstructive pulmonary disease (COPD). Therefore, we aimed to elucidate the physiological factors responsible for DH development during the 6-minute walk test (6MWT) in COPD patients and compare ventilatory response to the 6MWT in hyperinflators and non-hyperinflators. Methods A total of 105 consecutive subjects with stable COPD underwent a 6MWT, and the Borg dyspnea scale, oxygen saturation (SpO2), breathing pattern, and inspiratory capacity (IC) were recorded before and immediately after walking. The change in IC was measured, and subjects were divided into hyperinflators (ΔIC >0.0 L) and non-hyperinflators (ΔIC ≤0.0 L). Spirometry, the Modified Medical Research Council (MMRC) dyspnea scale and St George’s Respiratory Questionnaire (SGRQ) were also assessed. Results DH was present in 66.67% of subjects. ΔIC/IC was significantly and negatively correlated with the small airway function. On multiple stepwise regression analysis forced expiratory flow after exhaling 50% of the forced vital capacity (FEF50%) was the only predictor of ΔIC/IC. Non-hyperinflators had a higher post-walking VT (t=2.419, P=0.017) and post-walking VE (t=2.599, P=0.011) than the hyperinflators did. Age and resting IC were independent predictors of the 6-minute walk distance (6MWD) in hyperinflators. Conclusions DH was considerably common in subjects with COPD. Small airway function may partly contribute to the DH severity during walking. The ventilator response to the 6MWT differed between hyperinflators and non-hyperinflators. Resting hyperinflation is an important predictor of functional exercise capacity in hyperinflators. PMID:26380729

Six-minute-walk test in idiopathic pulmonary fibrosis: test validation and minimal clinically important difference.

PubMed

du Bois, Roland M; Weycker, Derek; Albera, Carlo; Bradford, Williamson Z; Costabel, Ulrich; Kartashov, Alex; Lancaster, Lisa; Noble, Paul W; Sahn, Steven A; Szwarcberg, Javier; Thomeer, Michiel; Valeyre, Dominique; King, Talmadge E

2011-05-01

The 6-minute-walk test (6MWT) is a practical and clinically meaningful measure of exercise tolerance with favorable performance characteristics in various cardiac and pulmonary diseases. Performance characteristics in patients with idiopathic pulmonary fibrosis (IPF) have not been systematically evaluated. To assess the reliability, validity, and responsiveness of the 6MWT and estimate the minimal clinically important difference (MCID) in patients with IPF. The study population included all subjects completing a 6MWT in a clinical trial evaluating interferon gamma-1b (n = 822). Six-minute walk distance (6MWD) and other parameters were measured at baseline and at 24-week intervals using a standardized protocol. Parametric and distribution-independent correlation coefficients were used to assess the strength of the relationships between 6MWD and measures of pulmonary function, dyspnea, and health-related quality of life. Both distribution-based and anchor-based methods were used to estimate the MCID. Comparison of two proximal measures of 6MWD (mean interval, 24 d) demonstrated good reliability (coefficient = 0.83; P < 0.001). 6MWD was weakly correlated with measures of physiologic function and health-related quality of life; however, values were consistently and significantly lower for patients with the poorest functional status, suggesting good construct validity. Importantly, change in 6MWD was highly predictive of mortality; a 24-week decline of greater than 50 m was associated with a fourfold increase in risk of death at 1 year (hazard ratio, 4.27; 95% confidence interval, 2.57- 7.10; P < 0.001). The estimated MCID was 24-45 m. The 6MWT is a reliable, valid, and responsive measure of disease status and a valid endpoint for clinical trials in IPF.

Heart rate slopes during 6-min walk test in pulmonary arterial hypertension, other lung diseases, and healthy controls.

PubMed

Tonelli, Adriano R; Wang, Xiao-Feng; Alkukhun, Laith; Zhang, Qi; Dweik, Raed A; Minai, Omar A

2014-06-01

Six-minute walk test (6MWT) continues to be a useful tool to determine the functional capacity in patients with vascular and other lung diseases; nevertheless, it has a limited ability to predict prognosis in this context. We tested whether the heart rate (HR) acceleration and decay slopes during the 6-m walk test are different in patients with pulmonary arterial hypertension (PAH), other lung diseases, and healthy controls. In addition, we assessed whether the HR slopes are associated with clinical worsening. Using a portable, signal-morphology-based, impedance cardiograph (PhysioFlow Enduro, Paris, France) with real-time wireless monitoring via a Bluetooth USB adapter we determined beat-by-beat HR. We included 50 subjects in this pilot study, 20 with PAH (all on PAH-specific treatment), 17 with other lung diseases (obstructive [n = 12, 71%] or restrictive lung diseases [5, 29%]), and 13 healthy controls. The beat-by-beat HR curves were significantly different among all three groups of subjects either during the activity or recovery of the 6MWT. HR curves were less steep in PAH than the other two groups (P < 0.001). HR acceleration rates were slower in patients with PAH or other lung diseases with progression of their disease (P < 0.001). In conclusion, the acceleration and decay slopes during 6MWT are different among patients with PAH, other lung diseases, and healthy controls. The HR slopes during 6MWT were steeper in patients without clinical worsening. © 2014 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Reproducibility of oxygen saturation monitoring during six-minute walk test and exercise stress test in patients with pulmonary arteriovenous malformations associated with hereditary hemorrhagic telangiectasia.

PubMed

Li, Walter; Niu, Bolin; Henderson, Katherine; Northrup, Veronika; Pollak, Jeffery S; Trow, Terence; Fahey, John; White, Robert I

2011-06-01

Patients with pulmonary arteriovenous malformations (PAVMs) are at risk for multiple complications and require close follow-up. We investigated the reproducibility of the 6-minute walk test (6MWT) and exercise stress test (EST) for the evaluation of low oxygen saturation in patients with PAVMs. Twenty-two patients with PAVMs, most of whom had hereditary hemorrhagic telangiectasia (HHT), participated in a Human Investigations Committee-approved protocol. Patients ranged from 9 to 74 years of age (mean 28) and had a broad spectrum of anatomic subtypes of PAVMs, including focal and diffuse. Standard 6MWT and cycle ergometry EST were both performed twice with adequate rest between tests. Heart rate (HR) and oxygen saturation were measured at the beginning and end of each test. Distance walked and maximum resistance was also recorded. The intraclass correlation coefficients (r(i)) at the end of 6MWT were as follows: HR (r(i) = 0.940; 95% confidence interval [CI] 0.863-0.975), oxygen saturation (r(i) = 0.973; 95% CI 0.933-0.989), and distance (r(i) = 0.942; 95% CI 0.867-0.975). The r(i)s at the end of EST were as follows: HR (r(i) = 0.941; 95% CI 0.865-0.975), oxygen saturation (r(i) = 0.993; 95% CI 0.982-0.997), and maximum resistance (r(i) = 0.941; 95% CI 0.864-0.975). 6MWT and EST were reproducible measures of exercise capacity and oxygen saturation and are potential adjunct tests in the follow-up assessment for patients with PAVMs.

Prevalence of overestimation or underestimation of the functional capacity using MRC score as compared to 6-minute walk test in patients with cardio-respiratory disorders.

PubMed

Callens, Etienne; Graba, Sémia; Essalhi, Mohamed; Gillet-Juvin, Karine; Chevalier-Bidaud, Brigitte; Chenu, Romain; Mahut, Bruno; Delclaux, Christophe

2014-09-01

The first objective of our study was to assess whether patients diagnosed with cardio-respiratory disorders report overestimation or underestimation on recall (Medical Research Council (MRC) dyspnea scale) of their true functional capacity (walked distance during a 6-minute walk test (6MWT)). The second objective was to assess whether the measurement of breathlessness at the end of a 6MWT (Borg score) may help to identify dyspneic patients on recall. The 6MWTs of 746 patients aged from 40 to 80 years who were diagnosed with either chronic obstructive pulmonary disease (COPD, n = 355), diffuse parenchymal lung disease (n = 140), pulmonary vascular diseases (n = 188) or congestive heart failure (n = 63) were selected from a prospective Clinical Database Warehouse. The percentage of patients who overestimated (MRC ≤ 2 with distance < lower limit of normal (LLN), 61/746, 8%; 95% confidence interval (CI): 6 to 10%) or underestimated (MRC > 2 with distance ≥LLN, 121/746, 16%; 95%CI: 14 to 19%) on recall their capacity was elevated. The overestimation seemed related to self-limitation, while the underestimation seemed related to patients who "work through" their breathing discomfort. These two latter groups of patients were mainly diagnosed with COPD. A Borg dyspnea score >3 (upper limit of normal) at the end of the 6MWT had 84% specificity for the prediction of a MRC score >1. Almost one fourth of patients suffering from cardio-pulmonary disorders overestimate or underestimate on recall their true functional capacity. An elevated Borg dyspnea score at the end of the 6MWT has a good specificity to predict dyspnea on recall.

Erdosteine reduces the exercise-induced oxidative stress in patients with severe COPD: Results of a placebo-controlled trial.

PubMed

Dal Negro, Roberto W; Visconti, Maria

2016-12-01

Erdosteine (ER), a multimechanism, mucoactive agent with anti-oxidant and anti-inflammatory properties, has been shown to improve lung function, decrease plasma reactive oxygen species (ROS), and 8-isoprostane levels in patients with chronic obstructive pulmonary disease (COPD). To assess vs. placebo the effect of ER on the exercise-induced oxidative stress by measuring and comparing the release of pro-inflammatory mediators in severe COPD patients. The double blind, placebo controlled study was carried out in 24 severe (GOLD Class III) COPD patients, aged >40 yr, randomized to receive either oral ER (600 mg/day, 8 males, mean age 70.5 yr) or placebo (9 males, mean age 70.8 yr) for 10 days. All patients performed a 6-min walking test (6MWT) before and after both treatments. Mean ROS plasma levels increased significantly, but equally, in each group following the baseline 6MWT (p = ns). At the end of both treatments, a significant difference in mean plasma ROS increase from baseline became clear between the ER (+14.6% ± 2.7) and the placebo group (+24.4% ± 3.8) after the second 6MWT (p < 0.025). A similar significant trend was proved for the mean 8-isoprostane increase, which changed from baseline by +14.1% ± 2.6 in the ER, and by +26.3 ± 2.9 in the placebo group, respectively, after the second 6MWT (p < 0.006). Data from the present study are suggesting that ER is effective in reducing the release of inflammatory mediators due to the exercise-induced oxidative stress in severe COPD patients. Copyright © 2016 Elsevier Ltd. All rights reserved.

Longitudinal effect of eteplirsen versus historical control on ambulation in Duchenne muscular dystrophy

PubMed Central

Goemans, Nathalie; Lowes, Linda P.; Alfano, Lindsay N.; Berry, Katherine; Shao, James; Kaye, Edward M.; Mercuri, Eugenio; Hamid, Hoda Abdel; Byrne, Barry J.; Connolly, Anne M.; Dracker, Robert A.; Matthew Frank, L.; Heydemann, Peter T.; O'Brien, Kevin C.; Sparks, Susan E.; Specht, Linda A.; Rodino‐Klapac, Louise; Sahenk, Zarife; Al‐Zaidy, Samiah; Cripe, Linda H.; Lewis, Sarah; M, Pane; E, Mazzone; S, Messina; GL, Vita; Bertini, D Amico A; Casimiro, Berardinelli A; Y, Torrente; F, Magri; GP, Comi; G, Baranello; T, Mongini; A, Pini; R, Battini; E, Pegoraro; C, Bruno; L, Politano; S, Previtali

2016-01-01

Objective To continue evaluation of the long‐term efficacy and safety of eteplirsen, a phosphorodiamidate morpholino oligomer designed to skip DMD exon 51 in patients with Duchenne muscular dystrophy (DMD). Three‐year progression of eteplirsen‐treated patients was compared to matched historical controls (HC). Methods Ambulatory DMD patients who were ≥7 years old and amenable to exon 51 skipping were randomized to eteplirsen (30/50mg/kg) or placebo for 24 weeks. Thereafter, all received eteplirsen on an open‐label basis. The primary functional assessment in this study was the 6‐Minute Walk Test (6MWT). Respiratory muscle function was assessed by pulmonary function testing (PFT). Longitudinal natural history data were used for comparative analysis of 6MWT performance at baseline and months 12, 24, and 36. Patients were matched to the eteplirsen group based on age, corticosteroid use, and genotype. Results At 36 months, eteplirsen‐treated patients (n = 12) demonstrated a statistically significant advantage of 151m (p < 0.01) on 6MWT and experienced a lower incidence of loss of ambulation in comparison to matched HC (n = 13) amenable to exon 51 skipping. PFT results remained relatively stable in eteplirsen‐treated patients. Eteplirsen was well tolerated. Analysis of HC confirmed the previously observed change in disease trajectory at age 7 years, and more severe progression was observed in patients with mutations amenable to exon skipping than in those not amenable. The subset of patients amenable to exon 51 skipping showed a more severe disease course than those amenable to any exon skipping. Interpretation Over 3 years of follow‐up, eteplirsen‐treated patients showed a slower rate of decline in ambulation assessed by 6MWT compared to untreated matched HC. Ann Neurol 2016;79:257–271 PMID:26573217

Improvements in Functional Exercise Capacity after a Residential Behavioural Change, Diet and Fitness Program for Obese Adults.

PubMed

Errickson, Sadye Paez; Kolotkin, Ronette L; Skidmore, Megan Simmons; Endress, Gerald; Østbye, Truls; Crosby, Ross; Eisenson, Howard

2016-06-01

Obese adults are at an increased risk for mobility-related problems. National guidelines recommend calorie restrictions and exercise for obese adults as a means to improve functional fitness capacity and to increase mobility. Yet, lifestyle weight loss interventions often fail to measure fitness changes. The aim of this study was to assess whether a 1-month, intensive behavioural change, diet and fitness intervention for overweight and obese adults would result in statistically significant and clinically meaningful changes in functional exercise. A pre-post test design was used in this study. Seventy-two participants (40 women, 32 men; mean baseline body mass index (BMI) = 42.6 + 9.0; mean age = 45.8 + 16.8) completed a modified 6-minute walk test (6MWT), performed on a treadmill, at baseline and at end of treatment. Significant improvements included decreased BMI (2.7 + 1.7 kg m(-2) , p < 0.001) and increased 6MWT distance (66.4 + 73.0 m, p < 0.001). The 6MWT improved by 66 m on average, a reported clinically meaningful difference. Greater improvements in the 6MWT were significantly correlated with greater weight loss and BMI reduction. Our findings suggest that rehabilitation beyond weight loss may be derived from participation in a brief, intensive behavioural change, diet and fitness programme. Physiotherapists are in a prime position to address the physical and motivational challenges participants face while living with severe obesity: targeting functional exercise capacity is one key strategy for addressing immobility associated with obesity. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Quality of life, symptom status and physical performance in patients with advanced non-small cell lung cancer undergoing chemotherapy: an exploratory analysis of secondary data.

PubMed

Shallwani, Shirin M; Simmonds, Maureen J; Kasymjanova, Goulnar; Spahija, Jadranka

2016-09-01

Our objectives were: (a) to identify predictors of change in health-related quality of life (HRQOL) in patients with advanced non-small cell lung cancer (NSCLC) undergoing chemotherapy; and (b) to characterize symptom status, nutritional status, physical performance and HRQOL in this population and to estimate the extent to which these variables change following two cycles of chemotherapy. A secondary analysis of a longitudinal observational study of 47 patients (24 men and 23 women) with newly diagnosed advanced NSCLC receiving two cycles of first-line chemotherapy was performed. Primary outcomes were changes in HRQOL (physical and mental component summaries (PCS and MCS) of the 36-item Short-Form Health Survey (SF-36)). Predictors in the models included pre-chemotherapy patient-reported symptoms (Schwartz Cancer Fatigue Scale (SCFS) and Lung Cancer Subscale), nutritional screening (Patient-Generated Subjective Global Assessment) and physical performance measures (6-min Walk Test (6MWT), one-minute chair rise test and grip strength). Mean SF-36 PCS score, 6MWT distance and grip strength declined following two cycles of chemotherapy (p<0.05). Multiple linear regression modelling revealed pre-chemotherapy SCFS score and 6MWT distance as the strongest predictors of change in the mental component of HRQOL accounting for 13% and 9% of the variance, respectively. No significant predictors were found for change in the physical component of HRQOL. Pre-chemotherapy 6MWT distance and fatigue severity predicted change in the mental component of HRQOL in patients with advanced NSCLC undergoing chemotherapy, while physical performance declined during treatment. Clinical management of these factors may be useful for HRQOL optimization in this population. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Study of body composition, lung function, and quality of life following use of anabolic steroids in patients with chronic obstructive pulmonary disease.

PubMed

Daga, Mradul Kumar; Khan, Naushad Ahmad; Malhotra, Varun; Kumar, Suman; Mawari, Govind; Hira, Harmanjit Singh

2014-04-01

Chronic obstructive pulmonary disease (COPD) is characterized by irreversible airflow limitation and is associated with weight loss and decreased muscle strength and exercise capacity. A double-blinded randomized controlled trial of 32 male COPD patients (age, 54.94 ± 11.27 years) was carried out to assess effects of anabolic steroid in terms of a daily high-protein, high-calorie diet alone or one combined with anabolic steroids on body composition, lung function, and health-related quality of life (HRQL). Outcomes were assessed by anthropometric and spirometric measurements, peak expiratory flow rate, partial pressure of oxygen in arterial blood, 6-minute walk test (6MWT), hand grip test, and HRQL index scores. Measurements were made at baseline and end of treatment (6 weeks). All patients showed significant difference (P < .001) in pulmonary function parameters and anthropometric measurements after 6 weeks of intervention (within-group changes); however, no significant improvement occurred in the pulmonary function parameters between the groups. The difference in exercise capacity (6MWT) and HRQL scores in the treatment group were statistically significant (P < .001) compared with control group after 6 weeks of intervention. In the treatment group, the average 6MWT distance increased from 213.5 m to 268.5 m at 6-week follow-up, and HRQL scores increased from 101.25 to 118.45. Also, HRQL and 6MWT parameters were positively correlated in response to steroid supplementation at the end of the study. Weekly administration of anabolic steroids during 6 weeks increased exercise capacity and quality of life in patients with COPD.

Exercise-Induced Changes in Exhaled NO Differentiates Asthma With or Without Fixed Airway Obstruction From COPD With Dynamic Hyperinflation.

PubMed

Huang, Shu-Yi; Chou, Pai-Chien; Wang, Tsai-Yu; Lo, Yu-Lun; Joa, Wen-Ching; Chen, Li-Fei; Sheng, Te-Fang; Chung, Kian Fan; Wang, Chun-Hua; Kuo, Han-Pin

2016-04-01

Asthmatic patients with fixed airway obstruction (FAO) and patients with chronic obstructive pulmonary disease (COPD) share similarities in terms of irreversible pulmonary function impairment. Exhaled nitric oxide (eNO) has been documented as a marker of airway inflammation in asthma, but not in COPD. To examine whether the basal eNO level and the change after exercise may differentiate asthmatics with FAO from COPD, 27 normal subjects, 60 stable asthmatics, and 62 stable COPD patients were studied. Asthmatics with FAO (n = 29) were defined as showing a postbronchodilator FEV1/forced vital capacity (FVC) ≤70% and FEV1 less than 80% predicted after inhaled salbutamol (400 μg). COPD with dynamic hyperinflation (n = 31) was defined as a decrease in inspiratory capacity (ΔIC%) after a 6 minute walk test (6MWT). Basal levels of eNO were significantly higher in asthmatics and COPD patients compared to normal subjects. The changes in eNO after 6MWT were negatively correlated with the percent change in IC (r = -0.380, n = 29, P = 0.042) in asthmatics with FAO. Their levels of basal eNO correlated with the maximum mid-expiratory flow (MMEF % predicted) before and after 6MWT. In COPD patients with air-trapping, the percent change of eNO was positively correlated to ΔIC% (rs = 0.404, n = 31, P = 0.024). We conclude that asthma with FAO may represent residual inflammation in the airways, while dynamic hyperinflation in COPD may retain NO in the distal airspace. eNO changes after 6MWT may differentiate the subgroups of asthma or COPD patients and will help toward delivery of individualized therapy for airflow obstruction.

Exercise-Induced Changes in Exhaled NO Differentiates Asthma With or Without Fixed Airway Obstruction From COPD With Dynamic Hyperinflation

PubMed Central

Huang, Shu-Yi; Chou, Pai-Chien; Wang, Tsai-Yu; Lo, Yu-Lun; Joa, Wen-Ching; Chen, Li-Fei; Sheng, Te-Fang; Chung, Kian Fan; Wang, Chun-Hua; Kuo, Han-Pin

2016-01-01

Abstract Asthmatic patients with fixed airway obstruction (FAO) and patients with chronic obstructive pulmonary disease (COPD) share similarities in terms of irreversible pulmonary function impairment. Exhaled nitric oxide (eNO) has been documented as a marker of airway inflammation in asthma, but not in COPD. To examine whether the basal eNO level and the change after exercise may differentiate asthmatics with FAO from COPD, 27 normal subjects, 60 stable asthmatics, and 62 stable COPD patients were studied. Asthmatics with FAO (n = 29) were defined as showing a postbronchodilator FEV1/forced vital capacity (FVC) ≤70% and FEV1 less than 80% predicted after inhaled salbutamol (400 μg). COPD with dynamic hyperinflation (n = 31) was defined as a decrease in inspiratory capacity (ΔIC%) after a 6 minute walk test (6MWT). Basal levels of eNO were significantly higher in asthmatics and COPD patients compared to normal subjects. The changes in eNO after 6MWT were negatively correlated with the percent change in IC (r = −0.380, n = 29, P = 0.042) in asthmatics with FAO. Their levels of basal eNO correlated with the maximum mid-expiratory flow (MMEF % predicted) before and after 6MWT. In COPD patients with air-trapping, the percent change of eNO was positively correlated to ΔIC% (rs = 0.404, n = 31, P = 0.024). We conclude that asthma with FAO may represent residual inflammation in the airways, while dynamic hyperinflation in COPD may retain NO in the distal airspace. eNO changes after 6MWT may differentiate the subgroups of asthma or COPD patients and will help toward delivery of individualized therapy for airflow obstruction. PMID:27082615

Correlations between gait speed, 6-minute walk distance, physical activity, and self-efficacy in patients with severe chronic lung disease.

PubMed

DePew, Zachary S; Karpman, Craig; Novotny, Paul J; Benzo, Roberto P

2013-12-01

Four-meter gait speed (4MGS) has been associated with functional capacity and overall mortality in elderly patients, and may easily be translated to daily practice. We evaluated the association of 4MGS with meaningful outcomes. In 70 subjects we conducted the 4MGS, 6-min walk test (6MWT), objectively measured physical activity, and assessed dyspnea, quality of life, and self-efficacy for walking and routine physical activity. 4MGS was measured in 3 separate time epochs during the 6MWT, to explore 4MGS variability. Diagnoses included COPD (51.4%), interstitial lung disease (38.6%), and other pulmonary conditions (10%). The mean ± SD values were: 4MGS 0.85 ± 0.21 m/s, 6-min walk distance (6MWD) 305 ± 115 m, and physical activity level 1.28 ± 0.17, which is consistent with severe physical inactivity. The gait speeds within the time epochs 1-2, 3-4, and 5-6 min during the 6MWT were not significantly different: 1.01 ± 0.29 m/s, 0.98 ± 0.31 m/s, and 1.00 ± 0.31 m/s, respectively. 4MGS had a significant correlation with 6MWD (r = 0.70, P < .001). 6MWD was the dominant variable for predicting 4MGS. Other significant predictors of 4MGS included dyspnea, self-efficacy, quality of life, and objectively measured physical activity. 4MGS is significantly and independently associated with 6MWD, and may serve as a reasonable simple surrogate for 6MWD in subjects with chronic lung disease. Gait speed was remarkably stable throughout the 6MWT, which supports the validity of an abbreviated walk test such as 4MGS.

Long-Term Follow-up to a Randomized Controlled Trial Comparing Peroneal Nerve Functional Electrical Stimulation to an Ankle Foot Orthosis for Patients With Chronic Stroke.

PubMed

Bethoux, Francois; Rogers, Helen L; Nolan, Karen J; Abrams, Gary M; Annaswamy, Thiru; Brandstater, Murray; Browne, Barbara; Burnfield, Judith M; Feng, Wuwei; Freed, Mitchell J; Geis, Carolyn; Greenberg, Jason; Gudesblatt, Mark; Ikramuddin, Farha; Jayaraman, Arun; Kautz, Steven A; Lutsep, Helmi L; Madhavan, Sangeetha; Meilahn, Jill; Pease, William S; Rao, Noel; Seetharama, Subramani; Sethi, Pramod; Turk, Margaret A; Wallis, Roi Ann; Kufta, Conrad

2015-01-01

Evidence supports peroneal nerve functional electrical stimulation (FES) as an effective alternative to ankle foot orthoses (AFO) for treatment of foot drop poststroke, but few long-term, randomized controlled comparisons exist. Compare changes in gait quality and function between FES and AFOs in individuals with foot drop poststroke over a 12-month period. Follow-up analysis of an unblinded randomized controlled trial (ClinicalTrials.gov #NCT01087957) conducted at 30 rehabilitation centers comparing FES to AFOs over 6 months. Subjects continued to wear their randomized device for another 6 months to final 12-month assessments. Subjects used study devices for all home and community ambulation. Multiply imputed intention-to-treat analyses were utilized; primary endpoints were tested for noninferiority and secondary endpoints for superiority. Primary endpoints: 10 Meter Walk Test (10MWT) and device-related serious adverse event rate. Secondary endpoints: 6-Minute Walk Test (6MWT), GaitRite Functional Ambulation Profile, and Modified Emory Functional Ambulation Profile (mEFAP). A total of 495 subjects were randomized, and 384 completed the 12-month follow-up. FES proved noninferior to AFOs for all primary endpoints. Both FES and AFO groups showed statistically and clinically significant improvement for 10MWT compared with initial measurement. No statistically significant between-group differences were found for primary or secondary endpoints. The FES group demonstrated statistically significant improvements for 6MWT and mEFAP Stair-time subscore. At 12 months, both FES and AFOs continue to demonstrate equivalent gains in gait speed. Results suggest that long-term FES use may lead to additional improvements in walking endurance and functional ambulation; further research is needed to confirm these findings. © The Author(s) 2015.

Assessment of In-Hospital Walking Velocity and Level of Assistance in a Powered Exoskeleton in Persons with Spinal Cord Injury.

PubMed

Yang, Ajax; Asselin, Pierre; Knezevic, Steven; Kornfeld, Stephen; Spungen, Ann M

2015-01-01

Individuals with spinal cord injury (SCI) often use a wheelchair for mobility due to paralysis. Powered exoskeletal-assisted walking (EAW) provides a modality for walking overground with crutches. Little is known about the EAW velocities and level of assistance (LOA) needed for these devices. The primary aim was to evaluate EAW velocity, number of sessions, and LOA and the relationships among them. The secondary aims were to report on safety and the qualitative analysis of gait and posture during EAW in a hospital setting. Twelve individuals with SCI ≥ 1.5 years who were wheelchair users participated. They wore a powered exoskeleton (ReWalk; ReWalk Robotics, Inc., Marlborough, MA) with Lofstrand crutches to complete 10-meter (10 MWT) and 6-minute (6MWT) walk tests. LOA was defined as modified independence (MI), supervision (S), minimal assistance (Min), and moderate assistance (Mod). Best effort EAW velocity, LOA, and observational gait analysis were recorded. Seven of 12 participants ambulated ≥ 0.40 m/s. Five participants walked with MI, 3 with S, 3 with Min, and 1 with Mod. Significant inverse relationships were noted between LOA and EAW velocity for both 6 MWT (Z value = 2.63, Rho = 0.79, P = .0086) and 10 MWT (Z value = 2.62, Rho = 0.79, P = .0088). There were 13 episodes of mild skin abrasions. MI and S groups ambulated with 2-point alternating crutch pattern, whereas the Min and Mod groups favored 3-point crutch gait. Seven of 12 individuals studied were able to ambulate at EAW velocities ≥ 0.40 m/s, which is a velocity that may be conducive to outdoor activity-related community ambulation. The ReWalk is a safe device for in-hospital ambulation.

Design and evaluation of a nondestructive fissile assay device for HTGR fuel samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

McNeany, S. R.; Knoll, R. W.; Jenkins, J. D.

1979-02-01

Nondestructive assay of fissile material plays an important role in nuclear fuel processing facilities. Information for product quality control, plant criticality safety, and nuclear materials accountability can be obtained from assay devices. All of this is necessary for a safe, efficient, and orderly operation of a production plant. Presented here is a design description and an operational evaluation of a device developed to nondestructively assay small samples of High-Temperature Gas-Cooled Reactor (HTGR) fuel. The measurement technique employed consists in thermal-neutron irradiation of a sample followed by pneumatic transfer to a high-efficiency neutron detector where delayed neutrons are counted. In general,more » samples undergo several irradiation and count cycles during a measurement. The total number of delayed-neutron counts accumulated is translated into grams of fissile mass through comparison with the counts accumulated in an identical irradiation and count sequence of calibration standards. Successful operation of the device through many experiments over a one-year period indicates high operational reliability. Tests of assay precision show this to be better than 0.25% for measurements of 10 min. Assay biases may be encountered if calibration standards are not representative of unknown samples, but reasonable care in construction and control of standards should lead to no more than 0.2% bias in the measurements. Nondestructive fissile assay of HTGR fuel samples by thermal-neutron irradiation and delayed-neutron detection has been demonstrated to be a rapid and accurate analysis technique. However, careful attention and control must be given to calibration standards to see that they remain representative of unknown samples.« less

IAEA Coordinated Research Project on HTGR Reactor Physics, Thermal-hydraulics and Depletion Uncertainty Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strydom, Gerhard; Bostelmann, F.

The continued development of High Temperature Gas Cooled Reactors (HTGRs) requires verification of HTGR design and safety features with reliable high fidelity physics models and robust, efficient, and accurate codes. The predictive capability of coupled neutronics/thermal-hydraulics and depletion simulations for reactor design and safety analysis can be assessed with sensitivity analysis (SA) and uncertainty analysis (UA) methods. Uncertainty originates from errors in physical data, manufacturing uncertainties, modelling and computational algorithms. (The interested reader is referred to the large body of published SA and UA literature for a more complete overview of the various types of uncertainties, methodologies and results obtained).more » SA is helpful for ranking the various sources of uncertainty and error in the results of core analyses. SA and UA are required to address cost, safety, and licensing needs and should be applied to all aspects of reactor multi-physics simulation. SA and UA can guide experimental, modelling, and algorithm research and development. Current SA and UA rely either on derivative-based methods such as stochastic sampling methods or on generalized perturbation theory to obtain sensitivity coefficients. Neither approach addresses all needs. In order to benefit from recent advances in modelling and simulation and the availability of new covariance data (nuclear data uncertainties) extensive sensitivity and uncertainty studies are needed for quantification of the impact of different sources of uncertainties on the design and safety parameters of HTGRs. Only a parallel effort in advanced simulation and in nuclear data improvement will be able to provide designers with more robust and well validated calculation tools to meet design target accuracies. In February 2009, the Technical Working Group on Gas-Cooled Reactors (TWG-GCR) of the International Atomic Energy Agency (IAEA) recommended that the proposed Coordinated Research Program (CRP) on the HTGR Uncertainty Analysis in Modelling (UAM) be implemented. This CRP is a continuation of the previous IAEA and Organization for Economic Co-operation and Development (OECD)/Nuclear Energy Agency (NEA) international activities on Verification and Validation (V&V) of available analytical capabilities for HTGR simulation for design and safety evaluations. Within the framework of these activities different numerical and experimental benchmark problems were performed and insight was gained about specific physics phenomena and the adequacy of analysis methods.« less

The first reference equations for the 6-minute walk distance over a 10 m course.

PubMed

Beekman, Emmylou; Mesters, Ilse; Gosselink, Rik; Klaassen, Mariska P M; Hendriks, Erik J M; Van Schayck, Onno C P; de Bie, Rob A

2014-09-01

As primary care practice space is mostly limited to 10 m, the 6-minute walk test (6MWT) over a 10 m course is a frequently used alternative to evaluate patients' performance in COPD. Considering that course length significantly affects distance walked in 6 minutes (6MWD), this study aims to develop appropriate reference equations for the 10 m 6MWT. 181 healthy subjects, aged 40-90 years, performed two standardised 6MWTs over a straight 10 m course in a cross-sectional study. Average distance achieved was 578±108 m and differed between males and females (p<0.001). Resulting sex-specific reference equations from multiple regression analysis included age, body mass index and change in heart rate, explaining 62% of the variance in 6MWD for males and 71% for females. The presented reference equations are the first to evaluate 6MWD over a 10 m course and expand the usefulness of the 6MWT. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Heart Rate Recovery, Physical Activity Level, and Functional Status in Subjects With COPD.

PubMed

Morita, Andrea A; Silva, Laís K O; Bisca, Gianna W; Oliveira, Joice M; Hernandes, Nidia A; Pitta, Fabio; Furlanetto, Karina C

2018-05-15

A normal heart rate reflects the balance between the sympathetic and parasympathetic autonomic nervous system. When the difference between heart rate at the end of an exercise test and after 1 min of recovery, known as the 1-min heart rate recovery, is ≤ 12 beats/min, this may indicate an abnormal delay. We sought to compare physical activity patterns and subjects' functional status with COPD with or without delayed 1-min heart rate recovery after the 6-min walk test (6MWT). 145 subjects with COPD (78 men, median [interquartile range (IQR)] age 65 [60-73] y, body mass index 25 [21-30] kg/m 2 , FEV 1 45 ± 15% predicted) were underwent the following assessments: spirometry, 6MWT, functional status, and physical activity in daily life (PADL). A delayed heart rate recovery of 1 min was defined as ≤ 12 beats/min. Subjects with delayed 1-min heart rate recovery walked a shorter distance in the 6MWT compared to subjects without delayed heart rate recovery (median [IQR] 435 [390-507] m vs 477 [425-515] m, P = .01; 81 [71-87] vs 87 [79-98]% predicted, P = .002). Regarding PADL, subjects with delayed heart rate recovery spent less time in the standing position (mean ± SD 185 ± 89 min vs 250 ± 107 min, P = .002) and more time in sedentary positions (472 ± 110 min vs 394 ± 129 min, P = .002). Scores based on the self-care domain of the London Chest Activity of Daily Living questionnaire and the activity domain of the Pulmonary Functional Status and Dyspnea questionnaire were also worse in the group with delayed heart rate recovery (6 ± 2 points vs 5 ± 2 points; P = .039 and 29 ± 24 points vs 19 ± 17 points; P = .037, respectively). Individuals with COPD who exhibit delayed 1-min heart rate recovery after the 6MWT exhibited worse exercise capacity as well as a more pronounced sedentary lifestyle and worse functional status than those without delayed heart rate recovery. Despite its assessment simplicity, heart rate recovery after the 6MWT can be further explored as a promising outcome in COPD. Copyright © 2018 by Daedalus Enterprises.

2-D Fused Image Reconstruction approach for Microwave Tomography: a theoretical assessment using FDTD Model.

PubMed

Bindu, G; Semenov, S

2013-01-01

This paper describes an efficient two-dimensional fused image reconstruction approach for Microwave Tomography (MWT). Finite Difference Time Domain (FDTD) models were created for a viable MWT experimental system having the transceivers modelled using thin wire approximation with resistive voltage sources. Born Iterative and Distorted Born Iterative methods have been employed for image reconstruction with the extremity imaging being done using a differential imaging technique. The forward solver in the imaging algorithm employs the FDTD method of solving the time domain Maxwell's equations with the regularisation parameter computed using a stochastic approach. The algorithm is tested with 10% noise inclusion and successful image reconstruction has been shown implying its robustness.

FINAL PROJECT REPORT - EVALUATION AND TESTING OF HTGR REACTOR BUILDING RESPONSE TO DEPRESSURIZATION ACCIDENTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

ALLIANCE LIMITED, NGNP INDUSTRY

This report provides a description of the project, summarizes each phase of the project, and ends with project conclusions. In addition, the report contains a descriptive index of the technical reports generated during the course of the project.

ICP-MS measurement of iodine diffusion in IG-110 graphite for HTGR/VHTR

NASA Astrophysics Data System (ADS)

Carter, L. M.; Brockman, J. D.; Robertson, J. D.; Loyalka, S. K.

2016-05-01

Graphite functions as a structural material and as a barrier to fission product release in HTGR/VHTR designs, and elucidation of transport parameters for fission products in reactor-grade graphite is thus required for reactor source terms calculations. We measured iodine diffusion in spheres of IG-110 graphite using a release method based on Fickain diffusion kinetics. Two sources of iodine were loaded into the graphite spheres; molecular iodine (I2) and cesium iodide (CsI). Measurements of the diffusion coefficient were made over a temperature range of 873-1293 K. We have obtained the following Arrhenius expressions for iodine diffusion:DI , CsI infused =(6 ×10-12 2/s) exp(30,000 J/mol RT) And,DI , I2 infused =(4 ×10-10 m2/s) exp(-11,000 J/mol RT ) The results indicate that iodine diffusion in IG-110 graphite is not well-described by Fickan diffusion kinetics. To our knowledge, these are the first measurements of iodine diffusion in IG-110 graphite.

AGR-2 and AGR-3/4 Release-to-Birth Ratio Data Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pham, Binh T.; Einerson, Jeffrey J.; Scates, Dawn M.

A series of Advanced Gas Reactor (AGR) irradiation tests is being conducted in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) in support of development and qualification of tristructural isotropic (TRISO) low enriched fuel used in the High Temperature Gas-cooled Reactor (HTGR). Each AGR test consists of multiple independently controlled and monitored capsules containing fuel compacts placed in a graphite cylinder shrouded by a steel shell. These capsules are instrumented with thermocouples embedded in the graphite enabling temperature control. AGR configuration and irradiation conditions are based on prismatic HTGR technology that is distinguished primarily through use of heliummore » coolant, a low-power-density ceramic core capable of withstanding very high temperatures, and TRISO coated particle fuel. Thus, these tests provide valuable irradiation performance data to support fuel process development, qualify fuel for normal operating conditions, and support development and validation of fuel performance and fission product transport models and codes.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

McMurray, Jacob W.; Lindemer, Terrence B.; Brown, Nicholas R.

There are three important failure mechanisms that must be controlled in high-temperature gas-cooled reactor (HTGR) fuel for certain higher burnup applications are SiC layer rupture, SiC corrosion by CO, and coating compromise from kernel migration. All are related to high CO pressures stemming from free O generated when uranium present as UO 2 fissions and the O is not subsequently bound by other elements. Furthermore, in the HTGR UCO kernel design, CO buildup from excess O is controlled by the inclusion of additional uranium in the form of a carbide, UC x. An approach for determining the minimum UC xmore » content to ensure negligible CO formation was developed and demonstrated using CALPHAD models and the Serpent 2 reactor physics and depletion analysis tool. Our results are intended to be more accurate than previous estimates by including more nuclear and chemical factors, in particular the effect of transmutation products on the oxygen distribution as the fuel kernel composition evolves with burnup.« less

Genetic Risk for Age-Related Cognitive Impairment Does Not Predict Cognitive Performance in Middle Age.

PubMed

Korthauer, Laura E; Awe, Elizabeth; Frahmand, Marijam; Driscoll, Ira

2018-05-26

Alzheimer's disease (AD) is characterized by memory loss and executive dysfunction, which correspond to structural changes to the medial temporal lobes (MTL) and prefrontal cortex (PFC), respectively. Given the overlap in cognitive deficits between healthy aging and the earliest stages of AD, early detection of AD remains a challenge. The goal of the present study was to study MTL- and PFC-dependent cognitive functioning in middle-aged individuals at genetic risk for AD or cognitive impairment who do not currently manifest any clinical symptoms. Participants (N = 150; aged 40-60 years) underwent genotyping of 47 single nucleotide polymorphisms (SNPs) in six genes previously associated with memory or executive functioning: APOE, SORL1, BDNF, TOMM40, KIBRA, and COMT. They completed two MTL-dependent tasks, the virtual Morris Water Task (vMWT) and transverse patterning discriminations task (TPDT), and the PFC-dependent reversal learning task. Although age was associated with poorer performance on the vMWT and TPDT within this middle-aged sample, there were no genotype-associated differences in cognitive performance. Although the vMWT and TPDT may be sensitive to age-related changes in cognition, carriers of APOE, SORL1, BDNF, TOMM40, KIBRA, and COMT risk alleles do not exhibit alteration in MTL- and PFC-dependent functioning in middle age compared to non-carriers.

Application of process tomography in gas-solid fluidised beds in different scales and structures

NASA Astrophysics Data System (ADS)

Wang, H. G.; Che, H. Q.; Ye, J. M.; Tu, Q. Y.; Wu, Z. P.; Yang, W. Q.; Ocone, R.

2018-04-01

Gas-solid fluidised beds are commonly used in particle-related processes, e.g. for coal combustion and gasification in the power industry, and the coating and granulation process in the pharmaceutical industry. Because the operation efficiency depends on the gas-solid flow characteristics, it is necessary to investigate the flow behaviour. This paper is about the application of process tomography, including electrical capacitance tomography (ECT) and microwave tomography (MWT), in multi-scale gas-solid fluidisation processes in the pharmaceutical and power industries. This is the first time that both ECT and MWT have been applied for this purpose in multi-scale and complex structure. To evaluate the sensor design and image reconstruction and to investigate the effects of sensor structure and dimension on the image quality, a normalised sensitivity coefficient is introduced. In the meantime, computational fluid dynamic (CFD) analysis based on a computational particle fluid dynamic (CPFD) model and a two-phase fluid model (TFM) is used. Part of the CPFD-TFM simulation results are compared and validated by experimental results from ECT and/or MWT. By both simulation and experiment, the complex flow hydrodynamic behaviour in different scales is analysed. Time-series capacitance data are analysed both in time and frequency domains to reveal the flow characteristics.

Effect of virtual reality training on walking distance and physical fitness in individuals with Parkinson's disease.

PubMed

de Melo, Gileno Edu Lameira; Kleiner, Ana Francisca Rozin; Lopes, Jamile Benite Palma; Dumont, Arislander Jonathan Lopes; Lazzari, Roberta Delasta; Galli, Manuela; Oliveira, Claudia Santos

2018-04-07

To evaluate the effects of gait training with virtual reality (VR) on walking distance and physical fitness in individuals with Parkinson's Disease (PD). Thirty-seven individuals with PD participated in this prospective, randomized, controlled clinical trial. They were randomly allocated to a control group submitted to conventional training (n = 12), a treadmill group submitted to gait training on a treadmill (n = 13) and a VR group submitted to gait training using the XboxTM (n = 12). Clinical measures, gait variables and the Six-Minute Walk Test (6MWT) were evaluated: pre-intervention, after one intervention session, post-intervention and follow up (30 days after intervention). The VR and treadmill groups travelled longer distances on the 6MWT and had faster gait speed in comparison to the control group. The VR and treadmill groups demonstrated an increase in pre-6MWT HR. The VR group had more intense HR after the first session and throughout training, but these gains were not maintained at the follow-up. The present findings demonstrate that gait training with a VR program is as effective as treadmill training with regard to gains in walking distance and improvements in temporal gait variables in individuals with PD.

Clinical tests performed in acute stroke identify the risk of falling during the first year: postural stroke study in Gothenburg (POSTGOT).

PubMed

Persson, Carina U; Hansson, Per-Olof; Sunnerhagen, Katharina S

2011-03-01

To assess the likelihood of clinical tests for postural balance, walking and motor skills, performed during the first week after stroke, identifying the risk of falling. Prospective study. Patients with first stroke. Assessments were carried out during the first week, and the occurrence of falls was recorded 3, 6 and 12 months after stroke onset. The tests used were: 10-Metre Walking Test (10MWT), Timed Up & Go, Swedish Postural Assessment Scale for Stroke Patients, Berg Balance Scale and Modified Motor Assessment Scale. Cut-off levels were obtained by receiver operation characteristic curves, and odds ratios were used to assess cut-off levels for falling. The analyses were based on 96 patients. Forty-eight percent had at least one fall during the first year. All tests were associated with the risk of falling. The highest predictive values were found for the 10MWT (positive predictive value 64%, negative predictive value 76%). Those subjects who were unable to perform the 10MWT had the highest odds ratio, 6.06 (95% confidence interval 2.66-13.84, p<0.001) of falling. Clinical tests used during the first week after stroke onset can, to some extent, identify those patients at risk of falling during the first year after stroke.

[Evaluation of exercise capacity in pulmonary arterial hypertension].

PubMed

Demir, Rengin; Küçükoğlu, Mehmet Serdar

2010-12-01

Pulmonary arterial hypertension (PAH) is a life-threatening disease characterized by increased pulmonary vascular resistance that leads to right ventricular failure. The most common clinical features of PAH are dyspnea and exercise intolerance. Measurement of exercise capacity is of considerable importance for the assessment of disease severity as well as routine monitoring of disease. Maximal, symptom-limited, cardiopulmonary exercise test (CPET) is the gold standard for the evaluation of exercise capacity, whereby functions of several systems involved in exercise can be assessed, including cardiovascular, respiratory, and metabolic systems. However, in order to derive the most useful diagnostic information on physiologic limitations to exercise, CPET requires maximal effort of the patient, which can be difficult and risky for some severely ill patients. Moreover, it requires specific exercise equipment and measurement systems, and experienced and trained personnel. Thus, routine clinical use of CPET to assess exercise capacity in patients with PAH may not always be feasible. A practical and simple alternative to CPET to determine exercise capacity is the 6-minute walk test (6MWT). It is simple to perform, safe, and reproducible. In contrast to CPET, the 6MWT reflects a submaximal level of exertion that is more consistent with the effort required for daily physical activities. This review focuses on the role of CPET and 6MWT in patients with PAH.

Combining Fast-Walking Training and a Step Activity Monitoring Program to Improve Daily Walking Activity After Stroke: A Preliminary Study.

PubMed

Danks, Kelly A; Pohlig, Ryan; Reisman, Darcy S

2016-09-01

To determine preliminary efficacy and to identify baseline characteristics predicting who would benefit most from fast walking training plus a step activity monitoring program (FAST+SAM) compared with fast walking training (FAST) alone in persons with chronic stroke. Randomized controlled trial with blinded assessors. Outpatient clinical research laboratory. Individuals (N=37) >6 months poststroke. Subjects were assigned to either FAST, which was walking training at their fastest possible speed on the treadmill (30min) and overground 3 times per week for 12 weeks, or FAST+SAM. The step activity monitoring program consisted of daily step monitoring with an activity monitor, goal setting, and identification of barriers to activity and strategies to overcome barriers. Daily step activity metrics (steps/day [SPD], time walking per day), walking speed, and 6-minute walk test (6MWT) distance. There was a significant effect of time for both groups, with all outcomes improving from pre- to posttraining (all P values <.05). The FAST+SAM was superior to FAST for 6MWT (P=.018), with a larger increase in the FAST+SAM group. The interventions had differential effectiveness based on baseline step activity. Sequential moderated regression models demonstrated that for subjects with baseline levels of step activity and 6MWT distances that were below the mean, the FAST+SAM intervention was more effective than FAST (1715±1584 vs 254±933 SPD; P<.05 for overall model and ΔR(2) for SPD and 6MWT). The addition of a step activity monitoring program to a fast walking training intervention may be most effective in persons with chronic stroke who have initial low levels of walking endurance and activity. Regardless of baseline performance, the FAST+SAM intervention was more effective for improving walking endurance. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Usefulness of the desaturation–distance ratio from the six-minute walk test for patients with COPD

PubMed Central

Fujimoto, Yukari; Oki, Yutaro; Kaneko, Masahiro; Sakai, Hideki; Misu, Shogo; Yamaguchi, Takumi; Mitani, Yuji; Yasuda, Hisafumi; Ishikawa, Akira

2017-01-01

Purpose A straightforward, noninvasive method is needed to assess emphysema and pulmonary hypertension (PH) in COPD patients. The desaturation–distance ratio (DDR) is an index derived from the distance traveled and level of desaturation during a six-minute walk test (6MWT); it has previously been shown to be associated with percentage of forced expiratory volume in the first second of expiration (%FEV1.0) and percentage of diffusion capacity of the lung for carbon monoxide (%DLCO). The aim of this study was to examine the associations between DDR and emphysema and PH. Patients and methods We collected the following data for 74 stable COPD outpatients: lung function tests (%FEV1.0 and %DLCO), 6MWT distance and desaturation, and area of emphysema on computed tomography (percentage of low attenuation area). Enlargement of the pulmonary artery (PA) was assessed by the ratio of the diameter of the PA to that of the aorta (PA:A ratio) as an index of PH. DDR was calculated by the distance traveled and the degree of desaturation reached during a 6MWT. The relationships between study outcomes were assessed with Spearman’s rank-correlation analysis. Receiver operating characteristic (ROC) curves were used to determine the threshold values with the optimum cutoff points for predicting severe or very severe airway obstruction, pulmonary diffusing capacity disorder, moderate or severe emphysema, and enlargement of the PA. Results DDR correlated significantly with %FEV1.0, %DLCO, %LAA, and PA:A ratio. DDR showed high accuracy (area under the ROC curve >0.7) for predicting severe or very severe airway obstruction, pulmonary diffusing capacity disorder, moderate or severe emphysema, and enlargement of the PA. Conclusion The results suggest that DDR is a good index of emphysema and PH in COPD patients. The 6MWT is widely used to assess COPD, and DDR could help with the early diagnosis of COPD. PMID:28919734

Combination of robot-assisted and conventional body-weight-supported treadmill training improves gait in persons with multiple sclerosis: a pilot study.

PubMed

Ruiz, Jennifer; Labas, Michele P; Triche, Elizabeth W; Lo, Albert C

2013-12-01

The majority of persons with multiple sclerosis (MS) experience problems with gait, which they characterize as highly disabling impairments that adversely impact their quality of life. Thus, it is crucial to develop effective therapies to improve mobility for these individuals. The purpose of this study was to determine whether combination gait training, using robot-assisted treadmill training followed by conventional body-weight-supported treadmill training within the same session, improved gait and balance in individuals with MS. This study tested combination gait training in 7 persons with MS. The participants were randomized into the immediate therapy group (IT group) or the delayed therapy group (DT group). In phase I of the trial, the IT group received treatment while the DT group served as a concurrent comparison group. In phase II of the trial, the DT group received treatment identical to the treatment received by the IT group in phase I. Outcome measures included the 6-Minute Walk Test (6MWT), the Timed 25-Foot Walk Test, velocity, cadence, and the Functional Reach Test (FRT). Nonparametric statistical techniques were used for analysis. Combination gait training resulted in significantly greater improvements in the 6MWT for the IT group (median change = +59 m) compared with Phase I DT group (median change = -8 m) (P = 0.08) and FRT (median change = +3.3 cm in IT vs -0.8 cm in the DT group phase I; P = 0.03). Significant overall pre-post improvements following combination gait training were found in 6MWT (+32 m; P = 0.02) and FRT (+3.3 cm; P = 0.06) for IT and Phase II DT groups combined. Combination of robot with body-weight-supported treadmill training gait training is feasible and improved 6MWT and FRT distances in persons with MS.Video Abstract available (see Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A62) for more insights from the authors.

Early 4-week cardiac rehabilitation exercise training in elderly patients after heart surgery.

PubMed

Eder, Barbara; Hofmann, Peter; von Duvillard, Serge P; Brandt, Dieter; Schmid, Jean-Paul; Pokan, Rochus; Wonisch, Manfred

2010-01-01

The aim of this study was to assess the effects on exercise performance of supplementing a standard cardiac rehabilitation program with additional exercise programming compared to the standard cardiac rehabilitation program alone in elderly patients after heart surgery. In this prospective, randomized controlled trial, 60 patients (32 men and 28 women, mean age 73.1 +/- 4.7 years) completed cardiac rehabilitation (initiated 12.2 +/- 4.9 days postsurgery). Subjects were assigned to either a control group (CG, standard cardiac rehabilitation program [n = 19]), or an intervention group (IG, additional walking [n = 19], or cycle ergometry training [n = 22]). A symptom limited cardiopulmonary exercise test and 6-minute walk test (6MWT) were performed before and after 4 weeks of cardiac rehabilitation. The MacNew questionnaire was used to assess quality of life (QOL). At baseline, no significant differences for peak oxygen uptake ((.)VO2), maximal power output, or the 6MWT were detected between IG and CG. Global QOL was significantly higher in IG. After 4 weeks of cardiac rehabilitation, patients significantly improved in absolute values of the cardiopulmonary exercise test, 6MWT, and QOL scores. Significant differences between groups were found for peak (.)VO2 (IG: 18.2 +/- 3.1 mL x kg x min vs. CG: 16.5 +/- 2.2 mL x kg x min, P < .05); maximal power output (IG: 72.2 +/- 16 W vs. CG: 60.7 +/- 15 W, P < .05); 6MWT (IG: 454.8 +/- 76.3 m vs. CG: 400.5 +/- 75.5 m, P < .05); and QOL global (IG: 6.5 +/- 0.5 vs. CG: 6.3 +/- 0.6, P < .05). The supplementation of additional walking or cycle exercise training to standard cardiac rehabilitation programming compared to standard cardiac rehabilitation alone in elderly patients after heart surgery leads to significantly better exercise tolerance.

The Effects of Functional Training, Bicycle Exercise, and Exergaming on Walking Capacity of Elderly Patients With Parkinson Disease: A Pilot Randomized Controlled Single-blinded Trial.

PubMed

Ferraz, Daniel Dominguez; Trippo, Karen Valadares; Duarte, Gabriel Pereira; Neto, Mansueto Gomes; Bernardes Santos, Kionna Oliveira; Filho, Jamary Oliveira

2018-05-01

To compare the effects of functional training, bicycle exercise, and exergaming on walking capacity of elderly with Parkinson disease (PD). A pilot randomized, controlled, single-blinded trial. A state reference health care center for elderly, a public reference outpatient clinic for the elderly. Elderly individuals (≥60 years of age; N=62) with idiopathic PD (stage 2 to 3 of modified Hoehn and Yahr staging scale) according to the London Brain Bank. The participants were randomly assigned to three groups. Group 1 (G1) participated in functional training (n=22); group 2 (G2) performed bicycle exercise (n=20), and group 3 (G3) trained with Kinect Adventures (Microsoft, Redmond, WA) exergames (n=20). The primary outcome measure was the 6-minute walk test (6MWT); secondary outcome measures were the 10-m walk test (10MWT), sitting-rising test (SRT), body mass index, Parkinson Disease Questionnaire-39, World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0), and 15-item Geriatric Depression Scale. All groups showed significant improvements in 6MWT (G1 P=.008; G2 P=.001; G3 P=.005), SRT (G1 P<.001; G2 P=.001; G3 P=.003), and WHODAS 2.0 (G1 P=.018; G2 P=.019; G3 P=.041). Only G3 improved gait speed in 10MWT (P=.11). G1 (P=.014) and G3 (P=.004) improved quality of life. No difference was found between groups. Eight weeks of exergaming can improve the walking capacity of elderly patients with PD. Exergame training had similar outcomes compared with functional training and bicycle exercise. The three physical exercise modalities presented significant improvements on walking capacity, ability to stand up and sit, and functionality of the participants. Copyright © 2018 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

The effect of atrial-based pacing on exercise capacity as measured by the 6-minute walk test: a substudy of the Canadian Trial of Physiological Pacing (CTOPP).

PubMed

Baranchuk, Adrian; Healey, Jeff S; Thorpe, Kevin E; Morillo, Carlos A; Nair, Girish; Crystal, Eugene; Kerr, Charles R; Connolly, Stuart J

2007-08-01

Although several randomized trials have detected no reduction in major cardiovascular events with the routine use of dual-chamber as opposed to ventricular pacemakers, many individuals continue to advocate their use as a means of improving exercise capacity. The Canadian Trial of Physiological Pacing (CTOPP) trial is the largest trial comparing ventricular pacing to atrial-based pacing (atrial or dual-chamber) in patients with bradycardia. All patients in this trial were asked to complete a 6-minute hall walk test (6MWT) at the time of their first study follow-up. The distance walked in 6 minutes and the patient's heart rate before and immediately after the walk were recorded. Of the 2568 patients in the CTOPP, 76% completed the 6MWT. The mean distance walked was 350 +/- 127 m in the ventricular pacing group and 356 +/- 127 m in the atrial-based group (P = NS). Similarly, there was no difference in the change in heart rate between the two groups (17 +/- 13 vs. 18 +/- 12 bpm: P = NS). However, among patients with an unpaced heart rate of

Combining fast walking training and a step activity monitoring program to improve daily walking activity after stroke: a preliminary study

PubMed Central

Danks, Kelly A.; Pohlig, Ryan; Reisman, Darcy S.

2016-01-01

Objective To determine preliminary efficacy and to identify baseline characteristics predicting who would benefit most from fast walking training plus a step activity monitoring program (FAST+SAM) compared to fast walking training alone (FAST) in persons with chronic stroke. Design Randomized controlled trial with blinded assessors Setting Outpatient clinical research laboratory Participants 37 individuals greater than 6 months post-stroke. Interventions Subjects were assigned to either FAST which was walking training at their fastest possible speed on the treadmill (30 minutes) and over ground 3 times/week for 12 weeks or FAST plus a step activity monitoring program (FAST+SAM). The step activity monitoring program consisted of daily step monitoring with a StepWatch Activity monitor, goal setting, and identification of barriers to activity and strategies to overcome barriers. Main Outcome Measures Daily step activity metrics (steps/day, time walking/day), walking speed and six minute walk test distance (6MWT). Results There was a significant effect of time for both groups with all outcomes improving from pre to post-training, (all p<0.05). The FAST+SAM was superior to FAST for 6MWT (p=0.018), with a larger increase in the FAST+SAM group. The interventions had differential effectiveness based on baseline step activity. Sequential moderated regression models demonstrated that for subjects with baseline levels of step activity and 6MWT distances that were below the mean, the FAST+SAM intervention was more effective than FAST (1715±1584 vs. 254±933 steps/day, respectively; p<0.05 for overall model and ΔR2 for steps/day and 6MWT). Conclusions The addition of a step activity monitoring program to a fast walking training intervention may be most effective in persons with chronic stroke that have initial low levels of walking endurance and activity. Regardless of baseline performance, the FAST + SAM intervention was more effective for improving walking endurance. PMID:27240430

Estimating exercise capacity from walking tests in elderly individuals with stable coronary artery disease.

PubMed

Mandic, Sandra; Walker, Robert; Stevens, Emily; Nye, Edwin R; Body, Dianne; Barclay, Leanne; Williams, Michael J A

2013-01-01

Compared with symptom-limited cardiopulmonary exercise test (CPET), timed walking tests are cheaper, well-tolerated and simpler alternative for assessing exercise capacity in coronary artery disease (CAD) patients. We developed multivariate models for predicting peak oxygen consumption (VO2peak) from 6-minute walk test (6MWT) distance and peak shuttle walk speed for elderly stable CAD patients. Fifty-eight CAD patients (72 SD 6 years, 66% men) completed: (1) CPET with expired gas analysis on a cycle ergometer, (2) incremental 10-meter shuttle walk test, (3) two 6MWTs, (4) anthropometric assessment and (5) 30-second chair stands. Linear regression models were developed for estimating VO2peak from 6MWT distance and peak shuttle walk speed as well as demographic, anthropometric and functional variables. Measured VO2peak was significantly related to 6MWT distance (r = 0.719, p < 0.001) and peak shuttle walk speed (r = 0.717, p < 0.001). The addition of demographic (age, gender), anthropometric (height, weight, body mass index, body composition) and functional characteristics (30-second chair stands) increased the accuracy of predicting VO2peak from both 6MWT distance and peak shuttle walk speed (from 51% to 73% of VO2peak variance explained). Addition of demographic, anthropometric and functional characteristics improves the accuracy of VO2peak estimate based on walking tests in elderly individuals with stable CAD. Implications for Rehabilitation Timed walking tests are cheaper, well-tolerated and simpler alternative for assessing exercise capacity in cardiac patients. Walking tests could be used to assess individual's functional capacity and response to therapeutic interventions when symptom-limited cardiopulmonary exercise testing is not practical or not necessary for clinical reasons. Addition of demographic, anthropometric and functional characteristics improves the accuracy of peak oxygen consumption estimate based on 6-minute walk test distance and peak shuttle walk speed in elderly patients with coronary artery disease.

Six-minute walking test predicts maximal fat oxidation in obese children.

PubMed

Makni, E; Moalla, W; Trabelsi, Y; Lac, G; Brun, J F; Tabka, Z; Elloumi, M

2012-07-01

Obesity is associated with reduced exercise maximal fat oxidation rate (FATmax), which is generally assessed by cardiopulmonary cycling test. The six-minute walking test (6MWT) presents an alternative method in patients. The aim of this study was to establish a practical reference equation facilitating the prediction of FATmax from the 6 MWT in obese children of both genders. This study is a cross-sectional study using mixed linear and multiple regression models. Anthropometric measurements were recorded and submaximal cycling test and 6 MWT conducted for 131 school-aged obese children, 68 boys and 63 girls. A multiple regression analysis for FATmax, including six-minute walking distance (6 MWD), anthropometric and cardiac parameters as the dependent variables, was performed for the two genders separately. Mean 6 MWD and FATmax were 564.9 ± 53.7 m and 126.5 ± 12.1 mg min(-1) for boys and 506.7 ± 55.0 m and 120.7 ± 10.0 mg min(-1) for girls, respectively. The 6MWD, body mass index, Z-score, fat-free mass, waist and hip circumferences (WC and HC), rest heart rate, and systolic and diastolic blood pressures were highly correlated with FATmax for both genders. There was a significant correlation between 6 MWD and FATmax in both boys and girls (r = 0.88 and r = 0.81, P<0.001, respectively). Stepwise regression analyses revealed that the combinations of 6 MWD with HC for boys and 6MWD with WC for girls improved the predictability of the model (R(2) = 0.81 for boys and R(2) = 0.72 for girls; P<0.001). In obese children, the 6MWT can be used to predict FATmax when formal test of exercise capacity and gas exchange analysis are unavailable or impractical. It is therefore possible to prescript targeted exercises at FATmax, without performing indirect calorimetry, just from a field test.

Single‐dose intravenous iron in Southeast Asian heart failure patients: A pilot randomized placebo‐controlled study (PRACTICE‐ASIA‐HF)

PubMed Central

Yeo, Poh Shuan Daniel; Hadi, Farid Abdul; Cushway, Timothy; Lee, Kim Yee; Yin, Fang Fang; Ching, Anne; Li, Ruili; Loh, Seet Yoong; Lim, Shir Lynn; Wong, Raymond Ching‐Chiew; Tai, Bee Choo; Richards, Arthur Mark; Lam, Carolyn S.P.

2018-01-01

Abstract Aims Iron deficiency is highly prevalent in Southeast Asians with heart failure (HF) and associated with worse outcomes. This trial aimed to assess the effect of intravenous iron in Southeast Asians hospitalized with decompensated HF. Methods and results Fifty patients hospitalized for acute decompensated HF, regardless of ejection fraction, with iron deficiency (defined as serum ferritin <300 ng/mL if transferrin saturation is <20%) were randomized to receive either one dose of intravenous ferric carboxymaltose (FCM) 1000 mg or placebo (0.9% saline) following HF stabilization and before discharge in two Singapore tertiary centres. The primary endpoint was difference in 6‐min walk test (6MWT) distance over 12 weeks, while secondary endpoints were quality of life assessed using validated Kansas City Cardiomyopathy Questionnaire (KCCQ) and Visual Analogue Scale (VAS). Improvement in 6MWT distance at Week 12 was observed in both FCM and placebo groups (from 252 ± 123 to 334 ± 128 m and from 243 ± 67 to 301 ± 83 m, respectively). Unadjusted analysis showed 6MWT distance for FCM exceeded that for placebo, but adjustment for baseline covariates and time attenuated this effect {adjusted mean difference between groups: 0.88 m [95% confidence interval (CI) −30.2 to 32.0, P = 0.956]}. KCCQ overall summary and VAS were similar in both groups [adjusted mean difference: KCCQ −1.48 (95% CI −8.27 to 5.31, P = 0.670) and VAS 0.26 (95% CI −0.33 to 0.86, P = 0.386)]. FCM was well tolerated with no serious treatment‐related adverse events. Conclusions Intravenous FCM administered pre‐discharge in Southeast Asians hospitalized with decompensated HF is clinically feasible. Changes in 6MWT distance should be measured beyond Week 12 to account for background therapy effects. PMID:29345426

Correlation of 6-min walk test with left ventricular function and quality of life in heart failure due to Chagas disease.

PubMed

Chambela, Mayara C; Mediano, Mauro F F; Ferreira, Roberto R; Japiassú, André M; Waghabi, Mariana C; da Silva, Gilberto M S; Saraiva, Roberto M

2017-10-01

To evaluate the correlation of the total distance walked during the six-minute walk test (6MWT) with left ventricular function and quality of life in patients with Chagas Disease (ChD) complicated by heart failure. This is a cross-sectional study of adult patients with ChD and heart failure diagnosed based on Framingham criteria. 6MWT was performed following international guidelines. New York Heart Association functional class, brain natriuretic peptide (BNP) serum levels, echocardiographic parameters and quality of life (SF-36 and MLHFQ questionnaires) were determined and their correlation with the distance covered at the 6MWT was tested. Forty adult patients (19 male; 60 ± 12 years old) with ChD and heart failure were included in this study. The mean left ventricular ejection fraction was 35 ± 12%. Only two patients (5%) ceased walking before 6 min had elapsed. There were no cardiac events during the test. The average distance covered was 337 ± 105 metres. The distance covered presented a negative correlation with BNP (r = -0.37; P = 0.02), MLHFQ quality-of-life score (r = -0.54; P = 0.002), pulmonary artery systolic pressure (r = -0.42; P = 0.02) and the degree of diastolic dysfunction (r = -0.36; P = 0.03) and mitral regurgitation (r = -0.53; P = 0.0006) and positive correlation with several domains of the SF-36 questionnaire. The distance walked during the 6MWT correlates with BNP, quality of life and parameters of left ventricular diastolic function in ChD patients with heart failure. We propose this test to be adopted in endemic areas with limited resources to aid in the identification of patients who need referral for tertiary centres for further evaluation and treatment. © 2017 John Wiley & Sons Ltd.

The functional exercise capacity and its correlates in obese treatment-seeking people with binge eating disorder: an exploratory study.

PubMed

Vancampfort, Davy; De Herdt, Amber; Vanderlinden, Johan; Lannoo, Matthias; Adriaens, An; De Hert, Marc; Stubbs, Brendon; Soundy, Andrew; Probst, Michel

2015-01-01

The primary aim was to compare the functional exercise capacity between obese treatment-seeking people with and without binge eating disorder (BED) and non-obese controls. The secondary aim was to identify clinical variables including eating and physical activity behaviour, physical complaints, psychopathology and physical self-perception variables in obese people with BED that could explain the variability in functional exercise capacity. Forty people with BED were compared with 20 age-, gender- and body mass index (BMI)-matched obese persons without BED and 40 age and gender matched non-obese volunteers. A 6-minute walk test (6MWT), the Baecke physical activity questionnaire, the Symptom Checklist-90, the Physical Self-Perception Profile and the Eating Disorder Inventory were administered. Physical complaints before and after the 6MWT were also documented. The distance achieved on the 6MWT was significantly lower in obese participants with BED (512.1 ± 75.8 m versus 682.7 ± 98.4, p < 0.05) compared to non-obese controls. No significant differences were found between obese participants with and without BED. Participants with BED reported significantly (p < 0.05) more musculoskeletal pain and fatigue after the walk test than obese and non-obese controls. A forward stepwise regression analysis demonstrated that sports participation and perceived physical strength explained 41.7% of the variance on the 6MWT in obese participants with BED. Physical activity participation, physical self-perception and perceived physical discomfort during walking should be considered when developing rehabilitation programs for obese people with BED. Rehabilitation programmes in people with binge eating disorder should incorporate a functional exercise capacity assessment. Clinicians involved in the rehabilitation of people with binge eating disorder should consider depression and lower self-esteem as potential barriers. Clinicians should take into account the frequently observed physical discomfort when developing rehabilitation programmes for people with binge eating disorder.

Oxygen desaturation during the six-minute walk test in COPD patients*

PubMed Central

Moreira, Maria Ângela Fontoura; de Medeiros, Gabriel Arriola; Boeno, Francesco Pinto; Sanches, Paulo Roberto Stefani; da Silva, Danton Pereira; Müller, André Frotta

2014-01-01

Objective: To evaluate the behavior of oxygen saturation curves throughout the six-minute walk test (6MWT) in patients with COPD. Methods: We included 85 patients, all of whom underwent spirometry and were classified as having moderate COPD (modCOPD, n = 30) or severe COPD (sevCOPD, n = 55). All of the patients performed a 6MWT, in a 27-m corridor with continuous SpO2 and HR monitoring by telemetry. We studied the SpO2 curves in order to determine the time to a 4% decrease in SpO2, the time to the minimum SpO2 (Tmin), and the post-6MWT time to return to the initial SpO2, the last designated recovery time (RT). For each of those curves, we calculated the slope. Results: The mean age in the modCOPD and sevCOPD groups was 66 ± 10 years and 62 ± 11 years, respectively. At baseline, SpO2 was > 94% in all of the patients; none received supplemental oxygen during the 6MWT; and none of the tests were interrupted. The six-minute walk distance did not differ significantly between the groups. The SpO2 values were lowest in the sevCOPD group. There was no difference between the groups regarding RT. In 71% and 63% of the sevCOPD and modCOPD group patients, respectively, a ≥ 4% decrease in SpO2 occurred within the first minute. We found that FEV1% correlated significantly with the ΔSpO2 (r = −0.398; p < 0.001), Tmin (r = −0.449; p < 0.001), and minimum SpO2 (r = 0.356; p < 0.005). Conclusions: In the sevCOPD group, in comparison with the modCOPD group, SpO2 was lower and the Tmin was greater, suggesting a worse prognosis in the former. PMID:25029644

Assessment of In-Hospital Walking Velocity and Level of Assistance in a Powered Exoskeleton in Persons with Spinal Cord Injury

PubMed Central

Yang, Ajax; Asselin, Pierre; Knezevic, Steven; Kornfeld, Stephen

2015-01-01

Background: Individuals with spinal cord injury (SCI) often use a wheelchair for mobility due to paralysis. Powered exoskeletal-assisted walking (EAW) provides a modality for walking overground with crutches. Little is known about the EAW velocities and level of assistance (LOA) needed for these devices. Objective: The primary aim was to evaluate EAW velocity, number of sessions, and LOA and the relationships among them. The secondary aims were to report on safety and the qualitative analysis of gait and posture during EAW in a hospital setting. Methods: Twelve individuals with SCI ≥1.5 years who were wheelchair users participated. They wore a powered exoskeleton (ReWalk; ReWalk Robotics, Inc., Marlborough, MA) with Lofstrand crutches to complete 10-meter (10MWT) and 6-minute (6MWT) walk tests. LOA was defined as modified independence (MI), supervision (S), minimal assistance (Min), and moderate assistance (Mod). Best effort EAW velocity, LOA, and observational gait analysis were recorded. Results: Seven of 12 participants ambulated ≥0.40 m/s. Five participants walked with MI, 3 with S, 3 with Min, and 1 with Mod. Significant inverse relationships were noted between LOA and EAW velocity for both 6MWT (Z value = 2.63, Rho = 0.79, P = .0086) and 10MWT (Z value = 2.62, Rho = 0.79, P = .0088). There were 13 episodes of mild skin abrasions. MI and S groups ambulated with 2-point alternating crutch pattern, whereas the Min and Mod groups favored 3-point crutch gait. Conclusion: Seven of 12 individuals studied were able to ambulate at EAW velocities ≥0.40 m/s, which is a velocity that may be conducive to outdoor activity-related community ambulation. The ReWalk is a safe device for in-hospital ambulation. PMID:26364279

Predictors and Association With Clinical Outcomes of the Changes in Exercise Capacity After Transcatheter Aortic Valve Replacement.

PubMed

Abdul-Jawad Altisent, Omar; Puri, Rishi; Regueiro, Ander; Chamandi, Chekrallah; Rodriguez-Gabella, Tania; Del Trigo, Maria; Campelo-Parada, Francisco; Couture, Thomas; Marsal, Josep Ramon; Côté, Mélanie; Paradis, Jean-Michel; DeLarochellière, Robert; Doyle, Daniel; Mohammadi, Siamak; Dumont, Eric; Rodés-Cabau, Josep

2017-08-15

At present, there are no objective data specifically examining the clinical impact of variations in exercise capacity post-transcatheter aortic valve replacement (TAVR). We describe the changes in exercise capacity between baseline and 6 months post-TAVR, and ascertain factors associated with and clinical implications of a lack of improvement in exercise capacity post-TAVR. A total of 305 patients (mean age, 79±9 years; 44% men; Society of Thoracic Surgeons predicted risk mortality score, 6.7±4.2%) undergoing TAVR completed both baseline and follow-up exercise capacity assessments at 6 months post-TAVR. Exercise capacity was evaluated by the 6-minute walk test (6MWT). Clinical outcomes were compared between patients displaying greater than (n=152; improving group) versus less than (n=153; nonimproving group) the median percentage change in distance walked between baseline and 6-month follow-up examinations. The primary outcome measure was clinical event rates, measured from the 6-month post-TAVR period onward. Further dichotomization according to baseline 6MWT distance (less than versus more than median walking distance, or slow walker versus fast walker) was also assessed. The mean overall distances walked pre- and post-TAVR (6 months post-TAVR) were 204±119 and 263±116 m, respectively (Δ6MWT=60±106 m), with 219 (72%) patients demonstrating an increase in their walking distance (median percentage increase of the entire population was 20% [interquartile range, 0%-80%]). Factors independently correlated with reduced exercise capacity improvement included a range of baseline clinical characteristics (older age, female sex, chronic obstructive pulmonary disease; P <0.05 for all), periprocedural major or life-threatening bleeding ( P =0.009) and new-onset anemia at 6 months post-TAVR ( P =0.009). Failure to improve the 6MWT distance by at least 20% was independently associated with all-cause mortality ( P =0.002) and cardiovascular death or rehospitalization for cardiovascular causes ( P =0.001). Baseline slow walkers who were able to improve the 6MWT distance presented with significantly better outcomes than nonimprovers ( P =0.01 for all-cause mortality; P =0.001 for cardiovascular end point). Approximately one-third of patients undergoing TAVR did not improve their exercise capacity postprocedure. The lack of functional improvement post-TAVR was predicted by a mix of baseline and periprocedural factors translating into poorer clinical outcomes. These results suggest that systematically implementing exercise capacity assessment pre- and post-TAVR may help to improve patient risk stratification. © 2017 American Heart Association, Inc.

2-D Fused Image Reconstruction approach for Microwave Tomography: a theoretical assessment using FDTD Model

PubMed Central

Bindu, G.; Semenov, S.

2013-01-01

This paper describes an efficient two-dimensional fused image reconstruction approach for Microwave Tomography (MWT). Finite Difference Time Domain (FDTD) models were created for a viable MWT experimental system having the transceivers modelled using thin wire approximation with resistive voltage sources. Born Iterative and Distorted Born Iterative methods have been employed for image reconstruction with the extremity imaging being done using a differential imaging technique. The forward solver in the imaging algorithm employs the FDTD method of solving the time domain Maxwell’s equations with the regularisation parameter computed using a stochastic approach. The algorithm is tested with 10% noise inclusion and successful image reconstruction has been shown implying its robustness. PMID:24058889

Six-Minute Walk Test Performance in Persons With Multiple Sclerosis While Using Passive or Powered Ankle-Foot Orthoses.

PubMed

Boes, Morgan K; Bollaert, Rachel E; Kesler, Richard M; Learmonth, Yvonne C; Islam, Mazharul; Petrucci, Matthew N; Motl, Robert W; Hsiao-Wecksler, Elizabeth T

2018-03-01

To determine whether a powered ankle-foot orthosis (AFO) that provides dorsiflexor and plantar flexor assistance at the ankle can improve walking endurance of persons with multiple sclerosis (MS). Short-term intervention. University research laboratory. Participants (N=16) with a neurologist-confirmed diagnosis of MS and daily use of a prescribed custom unilateral passive AFO. Three 6-minute walk tests (6MWTs), 1 per footwear condition: shoes (no AFO), prescribed passive AFO, and portable powered AFO (PPAFO). Assistive devices were worn on the impaired limb. Distance walked and metabolic cost of transport were recorded during each 6MWT and compared between footwear conditions. Each participant completed all three 6MWTs within the experimental design. PPAFO use resulted in a shorter 6MWT distance than did a passive AFO or shoe use. No differences were observed in metabolic cost of transport between footwear conditions. The current embodiment of this PPAFO did not improve endurance walking performance during the 6MWT in a sample of participants with gait impairment due to MS. Further research is required to determine whether expanded training or modified design of this powered orthosis can be effective in improving endurance walking performance in persons with gait impairment due to MS. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Six-minute walking test done in a hallway or on a treadmill: how close do the two methods agree?

PubMed

Lenssen, Antoine F; Wijnen, Lambert C A M; Vankan, Dion G; Van Eck, Bart H; Berghmans, Danielle P; Roox, George M

2010-12-01

The 6-min walking test (6-MWT) is probably the most widely used test to measure the functional capacity in cardiac rehabilitation. Although the American Thoracic Society recommends testing on a flat surface, treadmills are also used for testing. Therefore, we want to investigate the interchangeability of results of treadmill and hallway 6-MWT in a population of patients participating in a cardiac rehabilitation programme. Preexperimental design. University hospital Department of Cardiology and Physiotherapy. Patients entering the cardiac rehabilitation programme of the Maastricht University Cardiology Department. Agreement in 6-min walking distance between the hallway and treadmill test results were calculated by taking the mean difference between the two methods and the 95% confidence interval of the difference and plotting this against the average of the two test results. A Bland and Altman plot was constructed, showing the mean difference and the 95% limits of agreement between the two methods. Sixty-nine patients participated in this study. Mean difference between walking on a treadmill and walking in a hallway was 9 m in favour of the hallway test. The 95% limits of agreement were±118 m. Results of the 6-MWT conducted in a hallway or on a treadmill are not interchangeable, because of large between-test variations in the distances walked by individual participants.

Decrease in pulmonary function and oxygenation after lung resection

PubMed Central

Westerdahl, Elisabeth; Langer, Daniel; Souza, Domingos S.R.; Andreasen, Jan Jesper

2018-01-01

Respiratory deficits are common following curative intent lung cancer surgery and may reduce the patient's ability to be physically active. We evaluated the influence of surgery on pulmonary function, respiratory muscle strength and physical performance after lung resection. Pulmonary function, respiratory muscle strength (maximal inspiratory/expiratory pressure) and 6-min walk test (6MWT) were assessed pre-operatively, 2 weeks post-operatively and 6 months post-operatively in 80 patients (age 68±9 years). Video-assisted thoracoscopic surgery was performed in 58% of cases. Two weeks post-operatively, we found a significant decline in pulmonary function (forced vital capacity −0.6±0.6 L and forced expiratory volume in 1 s −0.43±0.4 L; both p<0.0001), 6MWT (−37.6±74.8 m; p<0.0001) and oxygenation (−2.9±4.7 units; p<0.001), while maximal inspiratory and maximal expiratory pressure were unaffected. At 6 months post-operatively, pulmonary function and oxygenation remained significantly decreased (p<0.001), whereas 6MWT was recovered. We conclude that lung resection has a significant short- and long-term impact on pulmonary function and oxygenation, but not on respiratory muscle strength. Future research should focus on mechanisms negatively influencing post-operative pulmonary function other than impaired respiratory muscle strength. PMID:29362707

Decrease in pulmonary function and oxygenation after lung resection.

PubMed

Brocki, Barbara Cristina; Westerdahl, Elisabeth; Langer, Daniel; Souza, Domingos S R; Andreasen, Jan Jesper

2018-01-01

Respiratory deficits are common following curative intent lung cancer surgery and may reduce the patient's ability to be physically active. We evaluated the influence of surgery on pulmonary function, respiratory muscle strength and physical performance after lung resection. Pulmonary function, respiratory muscle strength (maximal inspiratory/expiratory pressure) and 6-min walk test (6MWT) were assessed pre-operatively, 2 weeks post-operatively and 6 months post-operatively in 80 patients (age 68±9 years). Video-assisted thoracoscopic surgery was performed in 58% of cases. Two weeks post-operatively, we found a significant decline in pulmonary function (forced vital capacity -0.6±0.6 L and forced expiratory volume in 1 s -0.43±0.4 L; both p<0.0001), 6MWT (-37.6±74.8 m; p<0.0001) and oxygenation (-2.9±4.7 units; p<0.001), while maximal inspiratory and maximal expiratory pressure were unaffected. At 6 months post-operatively, pulmonary function and oxygenation remained significantly decreased (p<0.001), whereas 6MWT was recovered. We conclude that lung resection has a significant short- and long-term impact on pulmonary function and oxygenation, but not on respiratory muscle strength. Future research should focus on mechanisms negatively influencing post-operative pulmonary function other than impaired respiratory muscle strength.

Physical performance and clinical outcomes in dialysis patients: a secondary analysis of the EXCITE trial.

PubMed

Torino, Claudia; Manfredini, Fabio; Bolignano, Davide; Aucella, Filippo; Baggetta, Rossella; Barillà, Antonio; Battaglia, Yuri; Bertoli, Silvio; Bonanno, Graziella; Castellino, Pietro; Ciurlino, Daniele; Cupisti, Adamasco; D'Arrigo, Graziella; De Paola, Luciano; Fabrizi, Fabrizio; Fatuzzo, Pasquale; Fuiano, Giorgio; Lombardi, Luigi; Lucisano, Gaetano; Messa, Piergiorgio; Rapanà, Renato; Rapisarda, Francesco; Rastelli, Stefania; Rocca-Rey, Lisa; Summaria, Chiara; Zuccalà, Alessandro; Tripepi, Giovanni; Catizone, Luigi; Zoccali, Carmine; Mallamaci, Francesca

2014-01-01

Scarce physical activity predicts shorter survival in dialysis patients. However, the relationship between physical (motor) fitness and clinical outcomes has never been tested in these patients. We tested the predictive power of an established metric of motor fitness, the Six-Minute Walking Test (6MWT), for death, cardiovascular events and hospitalization in 296 dialysis patients who took part in the trial EXCITE (ClinicalTrials.gov Identifier: NCT01255969). During follow up 69 patients died, 90 had fatal and non-fatal cardiovascular events, 159 were hospitalized and 182 patients had the composite outcome. In multivariate Cox models - including the study allocation arm and classical and non-classical risk factors - an increase of 20 walked metres during the 6MWT was associated to a 6% reduction of the risk for the composite end-point (P=0.001) and a similar relationship existed between the 6MWT, mortality (P<0.001) and hospitalizations (P=0.03). A similar trend was observed for cardiovascular events but this relationship did not reach statistical significance (P=0.09). Poor physical performance predicts a high risk of mortality, cardiovascular events and hospitalizations in dialysis patients. Future studies, including phase-2 EXCITE, will assess whether improving motor fitness may translate into better clinical outcomes in this high risk population. © 2014 S. Karger AG, Basel.

Exercise capacity, muscle strength and fatigue in sarcoidosis.

PubMed

Marcellis, R G J; Lenssen, A F; Elfferich, M D P; De Vries, J; Kassim, S; Foerster, K; Drent, M

2011-09-01

The aim of this case-control study was to investigate the prevalence of exercise intolerance, muscle weakness and fatigue in sarcoidosis patients. Additionally, we evaluated whether fatigue can be explained by exercise capacity, muscle strength or other clinical characteristics (lung function tests, radiographic stages, prednisone usage and inflammatory markers). 124 sarcoidosis patients (80 males) referred to the Maastricht University Medical Centre (Maastricht, the Netherlands) were included (mean age 46.6±10.2 yrs). Patients performed a 6-min walk test (6MWT) and handgrip force (HGF), elbow flexor muscle strength (EFMS), quadriceps peak torque (QPT) and hamstring peak torque (HPT) tests. Maximal inspiratory pressure (P(I,max)) was recorded. All patients completed the Fatigue Assessment Scale (FAS) questionnaire. The 6MWT was reduced in 45% of the population, while HGF, EFMS, QPT and HPT muscle strength were reduced in 15, 12, 27 and 18%, respectively. P(I,max) was reduced in 43% of the population. The majority of the patients (81%) reported fatigue (FAS ≥22). Patients with reduced peripheral muscle strength of the upper and/or lower extremities were more fatigued and demonstrated impaired lung functions, fat-free mass, P(I,max), 6MWT and quality of life. Fatigue was neither predicted by exercise capacity, nor by muscle strength. Besides fatigue, exercise intolerance and muscle weakness are frequent problems in sarcoidosis. We therefore recommend physical tests in the multidisciplinary management of sarcoidosis patients, even in nonfatigued patients.

Active Video Gaming for Children with Cerebral Palsy: Does a Clinic-Based Virtual Reality Component Offer an Additive Benefit? A Pilot Study.

PubMed

Levac, Danielle; McCormick, Anna; Levin, Mindy F; Brien, Marie; Mills, Richard; Miller, Elka; Sveistrup, Heidi

2018-02-01

To compare changes in gross motor skills and functional mobility between ambulatory children with cerebral palsy who underwent a 1-week clinic-based virtual reality intervention (VR) followed by a 6-week, therapist-monitored home active video gaming (AVG) program and children who completed only the 6-week home AVG program. Pilot non-randomized controlled trial. Five children received 1 hour of VR training for 5 days followed by a 6-week home AVG program, supervised online by a physical therapist. Six children completed only the 6-week home AVG program. The Gross Motor Function Measure Challenge Module (GMFM-CM) and Six Minute Walk Test (6MWT) evaluated change. There were no significant differences between groups. The home AVG-only group demonstrated a statistically and clinically significant improvement in GMFM-CM scores following the 6-week AVG intervention (median difference 4.5 points, interquartile range [IQR] 4.75, p = 0.042). The VR + AVG group demonstrated a statistically and clinically significant decrease in 6MWT distance following the intervention (median decrease 68.2 m, IQR 39.7 m, p = 0.043). All 6MWT scores returned to baseline at 2 months post-intervention. Neither intervention improved outcomes in this small sample. Online mechanisms to support therapist-child communication for exercise progression were insufficient to individualize exercise challenge.

Sacubitril/valsartan and short-term changes in the 6-minute walk test: A pilot study.

PubMed

Beltrán, Paola; Palau, Patricia; Domínguez, Eloy; Faraudo, Mercedes; Núñez, Eduardo; Guri, Olga; Mollar, Anna; Sanchis, Juan; Bayés-Genís, Antoni; Núñez, Julio

2018-02-01

Impaired exercise capacity is the most disabling symptom in patients with heart failure with reduced ejection fraction (HFrEF). Despite sacubitril/valsartan showing reduced long-term morbidity and mortality over enalapril in HFrEF, its effects on short-term functional capacity remain uncertain. We sought to evaluate the effects of sacubitril/valsartan on a 30-day six-minute walk test in eligible patients with HFrEF. From November 1, 2016 to February 1, 2017, a total of 58 stable symptomatic patients with HFrEF were eligible for sacubitril/valsartan and underwent 6-MWT before and 30days after initiation of sacubitril/valsartan therapy. A mixed-effects model for repeated-measures was used to analyze the changes. Mean age was 70±11years. 72.4% males, 46.6% with ischemic heart disease, and 51.7% on NYHA functional class III were included. The mean (SD) values of baseline LVEF and 6MWT were 30±7%, and 300±89m, respectively. The median (IQR) of NT-proBNP at baseline was 2701pg/ml (1087-4200). Compared with baseline, the 6-MWT distance increased significantly at 30days by 13.9% (+∆=41.8m (33.4-50.2); p<0.001). In this pilot study, sacubitril/valsartan was associated with an improvement in exercise tolerance in symptomatic patients with HFrEF. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Criticality calculations of the Very High Temperature reactor Critical Assembly benchmark with Serpent and SCALE/KENO-VI

DOE PAGES

Bostelmann, Friederike; Hammer, Hans R.; Ortensi, Javier; ...

2015-12-30

Within the framework of the IAEA Coordinated Research Project on HTGR Uncertainty Analysis in Modeling, criticality calculations of the Very High Temperature Critical Assembly experiment were performed as the validation reference to the prismatic MHTGR-350 lattice calculations. Criticality measurements performed at several temperature points at this Japanese graphite-moderated facility were recently included in the International Handbook of Evaluated Reactor Physics Benchmark Experiments, and represent one of the few data sets available for the validation of HTGR lattice physics. Here, this work compares VHTRC criticality simulations utilizing the Monte Carlo codes Serpent and SCALE/KENO-VI. Reasonable agreement was found between Serpent andmore » KENO-VI, but only the use of the latest ENDF cross section library release, namely the ENDF/B-VII.1 library, led to an improved match with the measured data. Furthermore, the fourth beta release of SCALE 6.2/KENO-VI showed significant improvements from the current SCALE 6.1.2 version, compared to the experimental values and Serpent.« less

Optimization of 200 MWth and 250 MWt Ship Based Small Long Life NPP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fitriyani, Dian; Su'ud, Zaki

2010-06-22

Design optimization of ship-based 200 MWth and 250 MWt nuclear power reactors have been performed. The neutronic and thermo-hydraulic programs of the three-dimensional X-Y-Z geometry have been developed for the analysis of ship-based nuclear power plant. Quasi-static approach is adopted to treat seawater effect. The reactor are loop type lead bismuth cooled fast reactor with nitride fuel and with relatively large coolant pipe above reactor core, the heat from primary coolant system is directly transferred to watersteam loop through steam generators. Square core type are selected and optimized. As the optimization result, the core outlet temperature distribution is changing withmore » the elevation angle of the reactor system and the characteristics are discussed.« less

Water NSTF Design, Instrumentation, and Test Planning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lisowski, Darius D.; Gerardi, Craig D.; Hu, Rui

The following report serves as a formal introduction to the water-based Natural convection Shutdown heat removal Test Facility (NSTF) program at Argonne. Since 2005, this US Department of Energy (DOE) sponsored program has conducted large scale experimental testing to generate high-quality and traceable validation data for guiding design decisions of the Reactor Cavity Cooling System (RCCS) concept for advanced reactor designs. The most recent facility iteration, and focus of this report, is the operation of a 1/2 scale model of a water-RCCS concept. Several features of the NSTF prototype align with the conceptual design that has been publicly released formore » the AREVA 625 MWt SC-HTGR. The design of the NSTF also retains all aspects common to a fundamental boiling water thermosiphon, and thus is well poised to provide necessary experimental data to advance basic understanding of natural circulation phenomena and contribute to computer code validation. Overall, the NSTF program operates to support the DOE vision of aiding US vendors in design choices of future reactor concepts, advancing the maturity of codes for licensing, and ultimately developing safe and reliable reactor technologies. In this report, the top-level program objectives, testing requirements, and unique considerations for the water cooled test assembly are discussed, and presented in sufficient depth to support defining the program’s overall scope and purpose. A discussion of the proposed 6-year testing program is then introduced, which outlines the specific strategy and testing plan for facility operations. The proposed testing plan has been developed to meet the toplevel objective of conducting high-quality test operations that span across a broad range of single- and two-phase operating conditions. Details of characterization, baseline test cases, accident scenario, and parametric variations are provided, including discussions of later-stage test cases that examine the influence of geometric variations and off-normal configurations. The facility design follows, including as-built dimensions and specifications of the various mechanical and liquid systems, design choices for the test section, water storage tank, and network piping. Specifications of the instrumentation suite are then presented, along with specific information on performance windows, measurement uncertainties, and installation locations. Finally, descriptions of the control systems and heat removal networks are provided, which have been engineered to support precise quantification of energy balances and facilitate well-controlled test operations.« less

Reproducibility and Validity of the 6-Minute Walk Test Using the Gait Real-Time Analysis Interactive Lab in Patients with COPD and Healthy Elderly

PubMed Central

Meijer, Kenneth; Delbressine, Jeannet M.; Willems, Paul J.; Franssen, Frits M. E.; Wouters, Emiel F. M.; Spruit, Martijn A.

2016-01-01

Background The 6-minute walk test (6MWT) in a regular hallway is commonly used to assess functional exercise capacity in patients with chronic obstructive pulmonary disease (COPD). However, treadmill walking might provide additional advantages over overground walking, especially if virtual reality and self-paced treadmill walking are combined. Therefore, this study aimed to assess the reproducibility and validity of the 6MWT using the Gait Real-time Analysis Interactive Lab (GRAIL) in patients with COPD and healthy elderly. Methodology/Results Sixty-one patients with COPD and 48 healthy elderly performed two 6MWTs on the GRAIL. Patients performed two overground 6MWTs and healthy elderly performed one overground test. Differences between consecutive 6MWTs and the test conditions (GRAIL vs. overground) were analysed. Patients walked further in the second overground test (24.8 m, 95% CI 15.2–34.4 m, p<0.001) and in the second GRAIL test (26.8 m, 95% CI 13.9–39.6 m). Healthy elderly improved their second GRAIL test (49.6 m, 95% CI 37.0–62.3 m). The GRAIL 6MWT was reproducible (intra-class coefficients = 0.65–0.80). The best GRAIL 6-minute walk distance (6MWD) in patients was shorter than the best overground 6MWD (-27.3 ± 49.1 m, p<0.001). Healthy elderly walked further on the GRAIL than in the overground condition (23.6 ± 41.4 m, p<0.001). Validity of the GRAIL 6MWT was assessed and intra-class coefficient values ranging from 0.74–0.77 were found. Conclusion The GRAIL is a promising system to assess the 6MWD in patients with COPD and healthy elderly. The GRAIL 6MWD seems to be more comparable to the 6MWDs assessed overground than previous studies on treadmills have reported. Furthermore, good construct validity and reproducibility were established in assessing the 6MWD using the GRAIL in patients with COPD and healthy elderly. PMID:27607426

An impaired health related muscular fitness contributes to a reduced walking capacity in patients with schizophrenia: a cross-sectional study

PubMed Central

2013-01-01

Background Patients with schizophrenia report muscle weakness. The relation of this muscle weakness with performing daily life activities such as walking is however not yet studied. The aim of this study was to quantify walking capacity and health related muscular fitness in patients with schizophrenia compared with age-, gender and body mass index (BMI)-matched healthy controls. Secondly, we identified variables that could explain the variability in walking capacity and in health related muscular fitness in patients with schizophrenia. Methods A total of 100 patients with schizophrenia and 40 healthy volunteers were initially screened. Eighty patients with schizophrenia (36.8±10.0 years) and the 40 age-, gender- and body mass index (BMI)-matched healthy volunteers (37.1±10.3 years) were finally included. All participants performed a standing broad jump test (SBJ) and a six-minute walk test (6MWT) and filled out the International Physical Activity Questionnaire. Patients additionally had a fasting metabolic laboratory screening and were assessed for psychiatric symptoms. Results Patients with schizophrenia did have lower 6MWT (17.9%, p<0.001) [effect size (ES)=−1.01] and SBJ (14.1%, p<0.001) (ES=−0.57) scores. Patients were also less physically active (1291.0±1201.8 metabolic equivalent-minutes/week versus 2463.1±1365.3, p<0.001) (ES=−0.91) than controls. Schizophrenia patients with metabolic syndrome (MetS) (35%) had a 23.9% lower (p<0.001) SBJ-score and 22.4% (p<0.001) lower 6MWT-score than those without MetS. In multiple regression analysis, 71.8% of the variance in 6MWT was explained by muscular fitness, BMI, presence of MetS and physical activity participation, while 53.9% of the variance in SBJ-score was explained by age, illness duration, BMI and physical activity participation. Conclusions The walking capacity and health-related muscular fitness are impaired in patients with schizophrenia and both should be a major focus in daily clinical practice and future research. PMID:23286356

Utility of Equations to Estimate Peak Oxygen Uptake and Work Rate From a 6-Minute Walk Test in Patients With COPD in a Clinical Setting.

PubMed

Kirkham, Amy A; Pauhl, Katherine E; Elliott, Robyn M; Scott, Jen A; Doria, Silvana C; Davidson, Hanan K; Neil-Sztramko, Sarah E; Campbell, Kristin L; Camp, Pat G

2015-01-01

To determine the utility of equations that use the 6-minute walk test (6MWT) results to estimate peak oxygen uptake ((Equation is included in full-text article.)o2) and peak work rate with chronic obstructive pulmonary disease (COPD) patients in a clinical setting. This study included a systematic review to identify published equations estimating peak (Equation is included in full-text article.)o2 and peak work rate in watts in COPD patients and a retrospective chart review of data from a hospital-based pulmonary rehabilitation program. The following variables were abstracted from the records of 42 consecutively enrolled COPD patients: measured peak (Equation is included in full-text article.)o2 and peak work rate achieved during a cycle ergometer cardiopulmonary exercise test, 6MWT distance, age, sex, weight, height, forced expiratory volume in 1 second, forced vital capacity, and lung diffusion capacity. Estimated peak (Equation is included in full-text article.)o2 and peak work rate were estimated from 6MWT distance using published equations. The error associated with using estimated peak (Equation is included in full-text article.)o2 or peak work to prescribe aerobic exercise intensities of 60% and 80% was calculated. Eleven equations from 6 studies were identified. Agreement between estimated and measured values was poor to moderate (intraclass correlation coefficients = 0.11-0.63). The error associated with using estimated peak (Equation is included in full-text article.)o2 or peak work rate to prescribe exercise intensities of 60% and 80% of measured values ranged from mean differences of 12 to 35 and 16 to 47 percentage points, respectively. There is poor to moderate agreement between measured peak (Equation is included in full-text article.)o2 and peak work rate and estimations from equations that use 6MWT distance, and the use of the estimated values for prescription of aerobic exercise intensity would result in large error. Equations estimating peak (Equation is included in full-text article.)o2 and peak work rate are of low utility for prescribing exercise intensity in pulmonary rehabilitation programs.

Six-minute walk test in non-insulin-dependent diabetes mellitus patients living in Northwest Africa.

PubMed

Latiri, Imed; Elbey, Rihab; Hcini, Kamel; Zaoui, Afif; Charfeddine, Bessam; Maarouf, Mohamed Ridha; Tabka, Zouhair; Zbidi, Abdelkrim; Ben Saad, Helmi

2012-01-01

International recommendations of the exploration of non-insulin-dependent diabetes mellitus (NIDDM) are focused on deficiency and not incapacity. (1) To estimate the incapacity of NIDDM patients through the 6-minute walk test (6MWT) data. (2) To determine their 6-minute walk distance (6MWD) influencing factors (3) To compare data of NIDDM patient group (PG; n = 100) with those of two control groups (CG): CG1 (n = 174, healthy nonobese and nonsmoker); CG2 (n = 55, obese nondiabetic free from comorbidities). The anthropometric, socioeconomic, clinical, metabolic, and 6MWT data of 100 NIDDM patients (45 females) were collected. Total sample means ± standard deviation of age, weight, and height were 54 ± 8 years, 81 ± 14 kg, and 1.64 ± 0.09 m. (1) Measured 6MWD (566 ± 81 m) was significantly lower than the theoretical 6MWD (90% ± 12%). The profile of the PG carrying the 6MWT, was as follows: 23% had an abnormal 6MWD; at the end of the 6MWT, 21% and 12% had, respectively, a low heart rate and a high dyspnea (>5/10), and 4% had desaturation during the walk. The estimated "cardiorespiratory and muscular chain" age (68 ± 16 years) was significantly higher than the chronological age. (2) The factors that significantly influenced the 6MWD (r(2) = 0.58) are included in the following equation: 6MWD (m) = -73.94 × gender (0, male; 1, female) - 3.25 × age (years) + 7.33 × leisure activity score - 35.57 × obesity (0, no; 1, yes) + 32.86 × socioeconomic level (0, low; 1, high) - 27.67 × cigarette use (0, no; 1, yes) + 8.89 × resting oxyhemoglobin saturation - 105.48. (3) Compared to the CGs, the PG had a significantly (P < 0.05) lower 6MWD (100%+9% and 100%+8%, respectively, for the CG1 and CG2). NIDDM seems to accelerate the decline of the submaximal aerobic capacity evaluated through the 6MWD.

The retest reliability of the six-minute walk test in patients referred to a cardiac rehabilitation programme.

PubMed

Hanson, Lisa C; McBurney, Helen; Taylor, Nicholas F

2012-03-01

The purpose of this paper was to determine if the Six-minute Walk Test (6MWT) was a reliable exercise test for patients referred to cardiac rehabilitation when up to three tests were performed and to determine if test scores differed according to between-test time interval. Thirty adults aged 63 ± 7.9 years referred to cardiac rehabilitation participated in a repeated measures reliability trial. Participants completed three 6MWTs within a one-week period. Participants were randomly allocated to one of three groups: on the first day, Group A completed three walks, Group B completed two walks and Group C completed one walk. Relative reliability was expressed in a ratio (ICC(2,1) ), and absolute reliability was expressed in metres (95% confidence intervals) for group and individuals. The 6MWT demonstrated a high level of relative reliability (intraclass correlation coefficients [ICC] = 0.94) across the three walks. There was no statistically significant difference between the test scores of the three groups. However, there was an increase in distance walked from the first to the second to the third 6MWT. Absolute reliability indicated that a change of at least 44 m would be required to be interpreted as true change in a group, and at least 95 m to be interpreted as true change in an individual with 95% confidence. Three 6MWTs completed in relatively short timeframes were not sufficient for reliable results as there was an increase in the distance walked, and relatively large increases in distances would be required to be interpreted as change. It did not make any difference whether the tests were all completed on one day or over one week. This study highlighted problems that may arise when relying on reliability coefficients alone to interpret reliability. These results suggest that the 6MWT may not have sufficient reliability to be a suitable test to evaluate exercise tolerance in patients referred to cardiac rehabilitation. Copyright © 2011 John Wiley & Sons, Ltd.

Kinematic Validation of a Multi-Kinect v2 Instrumented 10-Meter Walkway for Quantitative Gait Assessments.

PubMed

Geerse, Daphne J; Coolen, Bert H; Roerdink, Melvyn

2015-01-01

Walking ability is frequently assessed with the 10-meter walking test (10MWT), which may be instrumented with multiple Kinect v2 sensors to complement the typical stopwatch-based time to walk 10 meters with quantitative gait information derived from Kinect's 3D body point's time series. The current study aimed to evaluate a multi-Kinect v2 set-up for quantitative gait assessments during the 10MWT against a gold-standard motion-registration system by determining between-systems agreement for body point's time series, spatiotemporal gait parameters and the time to walk 10 meters. To this end, the 10MWT was conducted at comfortable and maximum walking speed, while 3D full-body kinematics was concurrently recorded with the multi-Kinect v2 set-up and the Optotrak motion-registration system (i.e., the gold standard). Between-systems agreement for body point's time series was assessed with the intraclass correlation coefficient (ICC). Between-systems agreement was similarly determined for the gait parameters' walking speed, cadence, step length, stride length, step width, step time, stride time (all obtained for the intermediate 6 meters) and the time to walk 10 meters, complemented by Bland-Altman's bias and limits of agreement. Body point's time series agreed well between the motion-registration systems, particularly so for body points in motion. For both comfortable and maximum walking speeds, the between-systems agreement for the time to walk 10 meters and all gait parameters except step width was high (ICC ≥ 0.888), with negligible biases and narrow limits of agreement. Hence, body point's time series and gait parameters obtained with a multi-Kinect v2 set-up match well with those derived with a gold standard in 3D measurement accuracy. Future studies are recommended to test the clinical utility of the multi-Kinect v2 set-up to automate 10MWT assessments, thereby complementing the time to walk 10 meters with reliable spatiotemporal gait parameters obtained objectively in a quick, unobtrusive and patient-friendly manner.

Kinematic Validation of a Multi-Kinect v2 Instrumented 10-Meter Walkway for Quantitative Gait Assessments

PubMed Central

Geerse, Daphne J.; Coolen, Bert H.; Roerdink, Melvyn

2015-01-01

Walking ability is frequently assessed with the 10-meter walking test (10MWT), which may be instrumented with multiple Kinect v2 sensors to complement the typical stopwatch-based time to walk 10 meters with quantitative gait information derived from Kinect’s 3D body point’s time series. The current study aimed to evaluate a multi-Kinect v2 set-up for quantitative gait assessments during the 10MWT against a gold-standard motion-registration system by determining between-systems agreement for body point’s time series, spatiotemporal gait parameters and the time to walk 10 meters. To this end, the 10MWT was conducted at comfortable and maximum walking speed, while 3D full-body kinematics was concurrently recorded with the multi-Kinect v2 set-up and the Optotrak motion-registration system (i.e., the gold standard). Between-systems agreement for body point’s time series was assessed with the intraclass correlation coefficient (ICC). Between-systems agreement was similarly determined for the gait parameters’ walking speed, cadence, step length, stride length, step width, step time, stride time (all obtained for the intermediate 6 meters) and the time to walk 10 meters, complemented by Bland-Altman’s bias and limits of agreement. Body point’s time series agreed well between the motion-registration systems, particularly so for body points in motion. For both comfortable and maximum walking speeds, the between-systems agreement for the time to walk 10 meters and all gait parameters except step width was high (ICC ≥ 0.888), with negligible biases and narrow limits of agreement. Hence, body point’s time series and gait parameters obtained with a multi-Kinect v2 set-up match well with those derived with a gold standard in 3D measurement accuracy. Future studies are recommended to test the clinical utility of the multi-Kinect v2 set-up to automate 10MWT assessments, thereby complementing the time to walk 10 meters with reliable spatiotemporal gait parameters obtained objectively in a quick, unobtrusive and patient-friendly manner. PMID:26461498

High Frequency Monitoring of Isotopic Signatures Elucidates Potential Effects of Restoring Floodplain Habitat in the Sacramento-San Joaquin Delta, California, USA

NASA Astrophysics Data System (ADS)

Nakamoto, B. J.; Fogel, M. L.; Jeffres, C.; Viers, J. H.

2017-12-01

Increasing the quality and quantity of habitat for native species in the Sacramento-San Joaquin Delta is a high priority for California water managers. The McCormack-Williamson Tract (MWT) is a subsided island (38.253° N -121.284° W) situated at the confluence of the Cosumnes and Mokelumne rivers, near the inland extent of tidal influence. MWT experienced unexpected levee failure on February 11, 2017, during the wettest year of record for the Mokelumne-Cosumnes river system, which provided a unique opportunity to examine the potential trajectory of future restoration actions within the Delta. We carried out high frequency sampling (n=32, 13% of days) of suspended particulate organic matter (SPOM) and waters in the Mokelumne and Cosumnes river systems, including nearby sloughs, and the post-failure, flooded interior of MWT. Carbon (δ13C) and nitrogen (δ15N) isotopes in SPOM and δ2H and δ18O of waters were analyzed and in situ water quality data were collected in tandem, thus contextualizing isotopic data. Sampling was confined to an 8 km2 region surrounding MWT (6.7 km2 interior). This unintentional flooding provided a natural before-after-control-impact experiment to study the effect that sudden inundation of a Delta island can have on food web development and ecosystem function. Source waters were isotopically distinct (p<.01), and co-varied along the Global Meteoric Water Line (R2>0.9), providing a semi-conservative tracer of mixing. The δ13C values of SPOM varied between -37.3 and -23.9‰ and were significantly more negative on the flooded island by 1.2‰ (p<.01), possibly due to increased recycling of organic carbon concomitant with accelerated ecosystem metabolism. Concurrently, δ15N values varied between 1.0 and 12.4‰ and were not significantly different between riverine and flooded island sites. Our data indicate that this river system is highly dynamic over short periods of flood inundation (13 weeks) with new freshwater habitats exhibiting higher productivity than their riverine counterparts and could therefore increase autochthonous subsidies to downstream ecosystems.

Heart Rate Recovery After 6-Min Walk Test Predicts Survival in Patients With Idiopathic Pulmonary Fibrosis

PubMed Central

Swigris, Jeffrey J.; Swick, Jeff; Wamboldt, Frederick S.; Sprunger, David; du Bois, Roland; Fischer, Aryeh; Cosgrove, Gregory P.; Frankel, Stephen K.; Fernandez-Perez, Evans R.; Kervitsky, Dolly; Brown, Kevin K.

2009-01-01

Background: In patients with idiopathic pulmonary fibrosis (IPF), our objectives were to identify predictors of abnormal heart rate recovery (HRR) at 1 min after completion of a 6-min walk test (6MWT) [HRR1] and 2 min after completion of a 6MWT (HRR2), and to determine whether abnormal HRR predicts mortality. Methods: From 2003 to 2008, we identified IPF patients who had been evaluated at our center (n = 76) with a pulmonary physiologic examination and the 6MWT. We used logistic regression to identify predictors of abnormal HRR, the product-limit method to compare survival in the sample stratified on HRR, and Cox proportional hazards analysis to estimate the prognostic capability of abnormal HRR. Results: Cutoff values were 13 beats for abnormal HRR1 and 22 beats for HRR2. In a multivariable model, predictors of abnormal HRR1 were diffusing capacity of the lung for carbon monoxide (odds ratio [OR], 0.4 per 10% predicted; 95% confidence interval [CI], 0.2 to 0.7; p = 0.003), change in heart rate from baseline to maximum (OR, 0.9; 95% CI, 0.8 to 0.97; p = 0.01), and having a right ventricular systolic pressure > 35 mm Hg as determined by transthoracic echocardiogram (OR, 12.7; 95% CI, 2.0 to 79.7; p = 0.01). Subjects with an abnormal HRR had significantly worse survival than subjects with a normal HRR (for HRR1, p = 0.0007 [log-rank test]; for HRR2, p = 0.03 [log-rank test]); these results held for the subgroup of 30 subjects without resting pulmonary hypertension (HRR1, p = 0.04 [log-rank test]). Among several candidate variables, abnormal HRR1 appeared to be the most potent predictor of mortality (hazard ratio, 5.2; 95% CI, 1.8 to 15.2; p = 0.004). Conclusion: Abnormal HRR after 6MWT predicts mortality in IPF patients. Research is needed to confirm these findings prospectively and to examine the mechanisms of HRR in IPF patients. PMID:19395579

Effects of comprehensive geriatric assessment on physical fitness in an acute medical setting for frail elderly patients.

PubMed

Åhlund, Kristina; Bäck, Maria; Öberg, Birgitta; Ekerstad, Niklas

2017-01-01

Frail elderly people often use emergency care. During hospitalization, physical decline is common, implying an increased risk of adverse health outcomes. Comprehensive Geriatric Assessment (CGA) has been shown to be beneficial for these patients in hospital care. However, there is very limited evidence about the effects on physical fitness. The aim was to compare effects on physical fitness in the acute care of frail elderly patients at a CGA unit versus conventional care, 3 months after discharge. A clinical, prospective, controlled trial with two parallel groups was conducted. Patients aged ≥75 years, assessed as frail and in need of inpatient care, were assigned to a CGA unit or conventional care. Measurements of physical fitness, including handgrip strength (HS), timed up-and-go (TUG), and the 6-minute walk test (6-MWT) were made twice, at the hospital index care period and at the 3-month follow-up. Data were analyzed as the mean change from index to the 3-month follow-up, and dichotomized as decline versus stability/improvement in physical fitness. In all, 408 participants, aged 85.7±5.4 years, were included. The intervention group improved significantly in all components of physical fitness. The controls improved in TUG and declined in HS and 6-MWT. When the changes were dichotomized the intervention group declined to a lesser extent; HS p <0.001, 6-MWT p <0.001, TUG p <0.003. The regression analysis showed the following odds ratios (ORs) for how these outcomes were influenced by the intervention; HS OR 4.4 (confidence interval [CI] 95% 2.2-9.1), 6-MWT OR 13.9 (CI 95% 4.2-46.2), and TUG OR 2.5 (CI 95% 1.1-5.4). This study indicates that the acute care of frail elderly patients at a CGA unit is superior to conventional care in terms of preserving physical fitness at 3 months follow-up. CGA management may positively influence outcomes of great importance for these patients, such as mobility, strength, and endurance.

Extrapulmonary features of bronchiectasis: muscle function, exercise capacity, fatigue, and health status.

PubMed

Ozalp, Ozge; Inal-Ince, Deniz; Calik, Ebru; Vardar-Yagli, Naciye; Saglam, Melda; Savci, Sema; Arikan, Hulya; Bosnak-Guclu, Meral; Coplu, Lutfi

2012-06-11

There are limited number of studies investigating extrapulmonary manifestations of bronchiectasis. The purpose of this study was to compare peripheral muscle function, exercise capacity, fatigue, and health status between patients with bronchiectasis and healthy subjects in order to provide documented differences in these characteristics for individuals with and without bronchiectasis. Twenty patients with bronchiectasis (43.5 ± 14.1 years) and 20 healthy subjects (43.0 ± 10.9 years) participated in the study. Pulmonary function, respiratory muscle strength (maximal expiratory pressure - MIP - and maximal expiratory pressure - MEP), and dyspnea perception using the Modified Medical Research Council Dyspnea Scale (MMRC) were determined. A six-minute walk test (6MWT) was performed. Quadriceps muscle, shoulder abductor, and hand grip strength (QMS, SAS, and HGS, respectively) using a hand held dynamometer and peripheral muscle endurance by a squat test were measured. Fatigue perception and health status were determined using the Fatigue Severity Scale (FSS) and the Leicester Cough Questionnaire (LCQ), respectively. Number of squats, 6MWT distance, and LCQ scores as well as lung function testing values and respiratory muscle strength were significantly lower and MMRC and FSS scores were significantly higher in patients with bronchiectasis than those of healthy subjects (p < 0.05). In bronchiectasis patients, QMS was significantly associated with HGS, MIP and MEP (p < 0.05). The 6MWT distance was significantly correlated to LCQ psychological score (p < 0.05). The FSS score was significantly associated with LCQ physical and total and MMRC scores (p < 0.05). The LCQ psychological score was significantly associated with MEP and 6MWT distance (p < 0.05). Peripheral muscle endurance, exercise capacity, fatigue and health status were adversely affected by the presence of bronchiectasis. Fatigue was associated with dyspnea and health status. Respiratory muscle strength was related to peripheral muscle strength and health status, but not to fatigue, peripheral muscle endurance or exercise capacity. These findings may provide insight for outcome measures for pulmonary rehabilitation programs for patients with bronchiectasis.

Exercise hypoxaemia as a predictor of pulmonary hypertension in COPD patients without severe resting hypoxaemia.

PubMed

Nakahara, Yoshio; Taniguchi, Hiroyuki; Kimura, Tomoki; Kondoh, Yasuhiro; Arizono, Shinichi; Nishimura, Koichi; Sakamoto, Koji; Ito, Satoru; Ando, Masahiko; Hasegawa, Yoshinori

2017-01-01

Pulmonary hypertension (PH) in COPD is associated with morbidity and mortality. Previous studies showed a relationship between resting hypoxaemia and PH, but little is known about the relationship between exercise hypoxaemia and PH in COPD without resting hypoxaemia. A retrospective observational study of COPD patients without resting hypoxaemia was conducted to evaluate the relationships between exercise hypoxaemia and pulmonary haemodynamics. Clinical characteristics, pulmonary function, blood gas analysis, 6-min walk distance (6MWD) and oxygen saturation of peripheral artery (SpO 2 ) at the end of the 6-min walk test (6MWT) were reviewed. Correlation analysis and stepwise regression analysis were performed to identify the predictor of mean pulmonary artery pressure (mPAP). Eighty-four consecutive patients with a mean predicted forced expiratory volume in 1 s (FEV 1 ) of 47 ± 21% were evaluated. In univariate analysis, mPAP had negative correlations with age (r = -0.27, P < 0.05), arterial partial pressure of oxygen (PaO 2 , r = -0.24, P < 0.05), % predicted forced vital capacity (FVC, r = -0.28, P < 0.05), % predicted FEV 1 (r = -0.40, P < 0.001), FEV 1 /FVC ratio (r = -0.33, P < 0.005), % predicted diffusion capacity for carbon monoxide (DL CO , r = -0.40, P < 0.001), 6MWD (r = -0.40, P < 0.001) and SpO 2 at the end of the 6MWT (r = -0.74, P < 0.001). In stepwise regression analysis, SpO 2 at the end of the 6MWT and 6MWD remained as independent predictors of mPAP (R 2  = 0.60). In receiver operating characteristic (ROC) analysis, SpO 2 at the end of the 6MWT presented an area under the curve of 0.896 for the prediction of PH, with a sensitivity of 0.86 and specificity of 0.84 for the cut-off point of 81%. In addition to 6MWD, exercise hypoxaemia indicates PH in patients with COPD without resting hypoxaemia. © 2016 Asian Pacific Society of Respirology.

Mast cell deficiency attenuates acupuncture analgesia for mechanical pain using c-kit gene mutant rats.

PubMed

Cui, Xiang; Liu, Kun; Xu, Dandan; Zhang, Youyou; He, Xun; Liu, Hao; Gao, Xinyan; Zhu, Bing

2018-01-01

Acupuncture therapy plays a pivotal role in pain relief, and increasing evidence demonstrates that mast cells (MCs) may mediate acupuncture analgesia. The present study aims to investigate the role of MCs in acupuncture analgesia using c-kit gene mutant-induced MC-deficient rats. WsRC-Ws/Ws rats and their wild-type (WT) littermates (WsRC-+/+) were used. The number of MCs in skin of ST36 area was compared in two rats after immunofluorescence labeling. Mechanical withdrawal latency (MWL), mechanical withdrawal threshold (MWT), and thermal withdrawal latency (TWL) were measured on bilateral plantar for pain threshold evaluation before and after each stimulus. Acupuncture- and moxibustion-like stimuli (43°C, 46°C heat, 1 mA electroacupuncture [EA], 3 mA EA, and manual acupuncture [MA]) were applied randomly on different days. Fewer MCs were observed in the skin of ST36 in mutant rats compared to WT rats ( P <0.001). For pain thresholds, MWL and MWT were higher in WsRC-Ws/Ws compared to WsRC-+/+ on bilateral paws ( P <0.05), but TWL was not different between the two rats ( P >0.05). Bilateral MWL and MWT in WsRC-+/+ rats increased significantly after each stimulus compared to baseline ( P <0.01, P <0.001). In WsRC-Ws/Ws rats, only noxious stimuli could produce anti-nociceptive effects for mechanical pain (46°C, 3 mA EA, MA) ( P <0.01, P <0.001). Additionally, the net increases in MWL and MWT induced by most stimuli were greater in WT than in mutant rats ( P <0.05). For thermal nociception, either high- or low-intensity stimuli could significantly augment TWL in two rats ( P <0.001), and the net increases of TWL evoked by most stimuli were to the same extent in two genetic variants. MCs influence the basic mechanical but not thermal pain threshold. MCs participate in acupuncture analgesia in mechanical but not in thermal nociception, in that MC deficiency may attenuate the mechanical analgesia evoked by high-intensity stimuli and eliminate analgesia provoked by low-intensity stimuli.

The 6 minute walk test and performance of upper limb in ambulant duchenne muscular dystrophy boys.

PubMed

Pane, Marika; Mazzone, Elena Stacy; Sivo, Serena; Fanelli, Lavinia; De Sanctis, Roberto; D'Amico, Adele; Messina, Sonia; Battini, Roberta; Bianco, Flaviana; Scutifero, Marianna; Petillo, Roberta; Frosini, Silvia; Scalise, Roberta; Vita, Gian Luca; Bruno, Claudio; Pedemonte, Marina; Mongini, Tiziana; Pegoraro, Elena; Brustia, Francesca; Gardani, Alice; Berardinelli, Angela; Lanzillotta, Valentina; Viggiano, Emanuela; Cavallaro, Filippo; Sframeli, Maria; Bello, Luca; Barp, Andrea; Busato, Fabio; Bonfiglio, Serena; Rolle, Enrica; Colia, Giulia; Bonetti, Annamaria; Palermo, Concetta; Graziano, Alessandra; D'Angelo, Grazia; Pini, Antonella; Corlatti, Alice; Gorni, Ksenija; Baranello, Giovanni; Antonaci, Laura; Bertini, Enrico; Politano, Luisa; Mercuri, Eugenio

2014-10-07

The Performance of Upper Limb (PUL) test was specifically developed for the assessment of upper limbs in Duchenne muscular dystrophy (DMD). The first published data have shown that early signs of involvement can also be found in ambulant DMD boys. The aim of this longitudinal Italian multicentric study was to evaluate the correlation between the 6 Minute Walk Test (6MWT) and the PUL in ambulant DMD boys. Both 6MWT and PUL were administered to 164 ambulant DMD boys of age between 5.0 and 16.17 years (mean 8.82). The 6 minute walk distance (6MWD) ranged between 118 and 557 (mean: 376.38, SD: 90.59). The PUL total scores ranged between 52 and 74 (mean: 70.74, SD: 4.66). The correlation between the two measures was 0.499. The scores on the PUL largely reflect the overall impairment observed on the 6MWT but the correlation was not linear. The use of the PUL appeared to be less relevant in the very strong patients with 6MWD above 400 meters, who, with few exceptions had near full scores. In patients with lower 6MWD the severity of upper limb involvement was more variable and could not always be predicted by the 6MWD value or by the use of steroids. Our results confirm that upper limb involvement can already be found in DMD boys even in the ambulant phase.

Influencing factors of the 6-min walk distance in adult Arab populations: a literature review.

PubMed

Joobeur, Samah; Rouatbi, Sonia; Latiri, Imed; Sfaxi, Raoudha; Ben Saad, Helmi

2016-05-01

Background Walk tests, especially the 6-min walk-test (6MWT), are commonly used in order to evaluate submaximal exercise capacity. The primary outcome of the 6MWT is the 6-min walk-distance (6MWD). Numerous demographic, physiological and anthropometric factors can influence the 6MWD in healthy adults. Objective The purpose of the present review is to highlight and discuss the 6MWD influencing factors in healthy of the healthy adult Arab populations. Methods It is a review including a literature search, from 1970 to September 31th 2015 using the PubMed, the Science Direct databases and the World Wide Web on Google search engine. Reference lists of retrieved English/French articles were searched for any additional references. Results Six studies, conducted in Tunisia (n=2), Saudi Arabia (n=3) and Algeria (n=1) were included. All studies were conducted according to the 2002-American-thoracic-society guidelines for the 6MWT. In addition to anthropometric data (sex, age, height, weight, body mass index, lean mass), the following data were recognized as 6MWD influencing factors: schooling and socioeconomic levels, urban origin, parity, physical activity score or status, metabolic equivalent task for moderate activity, spirometric data, end-walk heart-rate, resting diastolic blood pressure, dyspnoea Borg value and niqab-wearing. Conclusion The 6MWD influencing factors in adult Arab populations are numerous and include some specific predictors such as parity, physical activity level and niqab-wearing.

Case report: Physical therapy management of axial dystonia.

PubMed

Voos, Mariana Callil; Oliveira, Tatiana de Paula; Piemonte, Maria Elisa Pimentel; Barbosa, Egberto Reis

2014-01-01

Few studies have described physical therapy approaches to provide functional independence and reduce pain in individuals with dystonia. This report describes the physical therapy treatment of a 46-year-old woman diagnosed with idiopathic segmental axial dystonia. For two years, the patient was treated with kinesiotherapy (active and resisted movements and stretching of neck and trunk muscles), abdominal taping (kinesiotaping techniques), functional training, and sensory tricks. She was assessed with parts I, II and III of Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS-I, TWSTRS-II and TWSTRS-III), Berg Balance Scale (BBS), Six-Minute Walk Test (6-MWT), and the motor domain of Functional Independence Measure (FIM-motor) before and after the two-year treatment and after the one year follow-up. Postural control and symmetry improved (TWSTRS-I: from 30 to 18), functional independence increased (TWSTRS-II: from 27 to 15; BBS: from 36 to 46; 6-MWT: from 0 to 480 meters (m); FIM-motor: from 59 to 81), and the pain diminished (TWSTRS-III: from 12 to 5). The functional improvement was retained after one year (TWSTRS-I: 14/35; TWRTRS-II: 12/30; TWRTRS-III: 5/20; BBS: 48/56; 6-MWT: 450 m; FIM-motor: 81/91). This program showed efficacy on providing a better control of the dystonic muscles and thus the doses of botulinum toxin needed to treat them could be reduced. Outcomes support the therapeutic strategies used to deal with this type of dystonia.

Six minute walking test and carbon monoxide diffusing capacity for non-small cell lung cancer: easy performed tests in every day practice.

PubMed

Zarogoulidis, Paul; Kerenidi, Theodora; Huang, Haidong; Kontakiotis, Theodoros; Tremma, Ourania; Porpodis, Konstantinos; Kalianos, Anastasios; Rapti, Ageliki; Foroulis, Christoforos; Zissimopoulos, Athanasios; Courcoutsakis, Nikolaos; Zarogoulidis, Konstantinos

2012-12-01

Several studies have demonstrated that reduced lung function is a significant risk factor for lung cancer and increased surgical risk in patients with operable stages of lung cancer. The aim of the study was to perform pulmonary function tests and investigate which is a favorable respiratory function test for overall survival between lung cancer stages. Lung function tests were performed to lung cancer patients with non-small cell lung cancer of stage I, II, III and IV (241 patients in total). They had the last follow-up consecutively between December 2006 and July 2008. The staging was decided according to the sixth edition of TNM classification of NSCLC. The Forced Expiratory Volume in 1sec (FEV1), Forced Vital Capacity (FVC) and Carbon Monoxide Diffusing Capacity (DLCO) were measured according to American Thoracic Society/European Respiratory Society guidelines. The 6 Minute Walking Test (6MWT) was measured according to the American Thoracic Society. There was a significant association of the DLCO upon diagnosis and overall survival for stage II (P<0.007) and IV (P<0.003). Furthermore, there was a significant association between 6MWT and overall survival for stage III (P<0.001) and stage IV (P<0.010). The significance for each lung function test is different among the stages of NSCLC. DLCO and 6MWT upon admission are the most valuable prognostic factors for overall survival of NSCLC.

Reference equations for 6-min walk test in healthy Indian subjects (25-80 years).

PubMed

Palaniappan Ramanathan, Ramanathan; Chandrasekaran, Baskaran

2014-01-01

Six-min walk test (6MWT), a simple functional capacity evaluation tool used globally to determine the prognosis and effectiveness of any therapeutic/medical intervention. However, variability in reference equations derived from western population (due to racial and ethnicity variations) hinders from adequate use of 6MWT clinically. Further, there are no valid Indian studies that predict reference values for 6-min walk distance (6MWD) in healthy Indian normal. We aimed for framing individualized reference equations for 6MWT in healthy Indian population. Anthropometric variables (age, weight, height, and body mass index (BMI)) and 6-min walk in a 30 m corridor were evaluated in 125 subjects (67 females) in a cross-sectional trial. 6MWD significantly correlated with age (r = -0.29), height (r = 0.393), weight (r = 0.08), and BMI (r = -0.17). The gender specific reference equations for healthy Indian individuals were: (1) Males: 561.022 - (2.507 × age [years]) + (1.505 × weight [kg]) - (0.055 × height [cm]). R (2) = 0.288. (2) Indian females: 30.325 - (0.809 × age [years]) - (2.074 × weight [kg]) + (4.235 × height [cm]). R (2) = 0.272. Though the equations possess a small coefficient of determination and larger standard error estimate, the former applicability to Indian population is justified. These reference equations are probably most appropriate for evaluating the walked capacity of Indian patients with chronic diseases.

A structural equation model of the relationship between muscle strength, balance performance, walking endurance and community integration in stroke survivors

PubMed Central

2017-01-01

Purpose To use structural equation modelling (SEM) to determine (1) the direct and indirect associations of strength of paretic lower limb muscles with the level of community integration, and (2) the direct association of walking endurance and balance performance with the level of community integration in community-dwelling stroke survivors. Materials and methods In this cross-sectional study of 105 stroke survivors, the Subjective Index of Physical and Social Outcome (SIPSO) was used to measure the level of community integration. Lower-limb strength measures included isometric paretic ankle strength and isokinetic paretic knee peak torque. The Berg Balance Scale (BBS) and the 6-minute walk test (6MWT) were used to evaluate balance performance and walking endurance, respectively. Results SEM revealed that the distance walked on the 6MWT had the strongest direct association with the SIPSO score (β = 0.41, p <0.001). An increase of one standard deviation in the 6MWT distance resulted in an increase of 0.41 standard deviations in the SIPSO score. Moreover, dorsiflexion strength (β = 0.18, p = 0.044) and the BBS score (β = 0.21, p = 0.021) had direct associations with the SIPSO score. Conclusions The results of the proposed model suggest that rehabilitation training of community-dwelling stroke survivors could focus on walking endurance, balance performance and dorsiflexor muscle strengthening if the aim is to augment the level of community integration. PMID:29049293

Evaluation of potentially modifiable physical factors as predictors of health status in knee osteoarthritis patients referred for physical therapy.

PubMed

Gonçalves, Rui Soles; Pinheiro, João Páscoa; Cabri, Jan

2012-08-01

The purpose of this cross sectional study was to estimate the contributions of potentially modifiable physical factors to variations in perceived health status in knee osteoarthritis (OA) patients referred for physical therapy. Health status was measured by three questionnaires: Knee injury and Osteoarthritis Outcome Score (KOOS); Knee Outcome Survey - Activities of Daily Living Scale (KOS-ADLS); and Medical Outcomes Study - 36 item Short Form (SF-36). Physical factors were measured by a battery of tests: body mass index (BMI); visual analog scale (VAS) of pain intensity; isometric dynamometry; universal goniometry; step test (ST); timed "up and go" test (TUGT); 20-meter walk test (20MWT); and 6-minute walk test (6MWT). All tests were administered to 136 subjects with symptomatic knee OA (94 females, 42 males; age: 67.2 ± 7.1 years). Multiple stepwise regression analyses revealed that knee muscle strength, VAS of pain intensity, 6MWT, degree of knee flexion and BMI were moderate predictors of health status. In the final models, selected combinations of these potentially modifiable physical factors explained 22% to 37% of the variance in KOOS subscale scores, 40% of the variance in the KOS-ADLS scale score, and 21% to 34% of the variance in physical health SF-36 subscale scores. More research is required in order to evaluate whether therapeutic interventions targeting these potentially modifiable physical factors would improve health status in knee OA patients. Copyright © 2011 Elsevier B.V. All rights reserved.

Prognostication in Pulmonary Arterial Hypertension with Submaximal Exercise Testing.

PubMed

Khatri, Vinod; Neal, Jennifer E; Burger, Charles D; Lee, Augustine S

2015-02-06

The submaximal exercise test (SET), which gives both a measure of exercise tolerance, as well as disease severity, should be a more robust functional and prognostic marker than the six-minute walk test (6MWT). This study aimed to determine the prognostic value of SET as predicted by the validated REVEAL (Registry to Evaluate Early and Long-Term Pulmonary Artery Hypertension Disease Management) registry risk score (RRRS). Sixty-five consecutive patients with idiopathic and associated pulmonary arterial hypertension (PAH) underwent right-heart catheterization, echocardiogram, 6MWT and a three-minute SET (Shape-HF™). Analyses explored the association between SET variables and prognosis predicted by the RRRS. Although multiple SET variables correlated with the RRRS on univariate analyses, only V E /V CO2 (r = 0.57, p < 0.0001) remained an independent predictor in multivariate analysis (β = 0.05, p = 0.0371). Additionally, the V E /V CO2 was the most discriminatory (area under receiver operating characteristic curve, 0.84) in identifying the highest-risk category (RRRS ≥ 10), with an optimal cut-off of 40.6, resulting in a high sensitivity (92%) and negative-predictive value (97%), but a lower specificity (67%). SETs, particularly the V E /V CO2 , appear to have prognostic value when compared to the RRRS. If validated in prospective trials, SET should prove superior to the 6MWT or the RRRS, with significant implications for both future clinical trials and clinical practice.

An integrated gait rehabilitation training based on Functional Electrical Stimulation cycling and overground robotic exoskeleton in complete spinal cord injury patients: Preliminary results.

PubMed

Mazzoleni, S; Battini, E; Rustici, A; Stampacchia, G

2017-07-01

The aim of this study is to investigate the effects of an integrated gait rehabilitation training based on Functional Electrical Stimulation (FES)-cycling and overground robotic exoskeleton in a group of seven complete spinal cord injury patients on spasticity and patient-robot interaction. They underwent a robot-assisted rehabilitation training based on two phases: n=20 sessions of FES-cycling followed by n= 20 sessions of robot-assisted gait training based on an overground robotic exoskeleton. The following clinical outcome measures were used: Modified Ashworth Scale (MAS), Numerical Rating Scale (NRS) on spasticity, Penn Spasm Frequency Scale (PSFS), Spinal Cord Independence Measure Scale (SCIM), NRS on pain and International Spinal Cord Injury Pain Data Set (ISCI). Clinical outcome measures were assessed before (T0) after (T1) the FES-cycling training and after (T2) the powered overground gait training. The ability to walk when using exoskeleton was assessed by means of 10 Meter Walk Test (10MWT), 6 Minute Walk Test (6MWT), Timed Up and Go test (TUG), standing time, walking time and number of steps. Statistically significant changes were found on the MAS score, NRS-spasticity, 6MWT, TUG, standing time and number of steps. The preliminary results of this study show that an integrated gait rehabilitation training based on FES-cycling and overground robotic exoskeleton in complete SCI patients can provide a significant reduction of spasticity and improvements in terms of patient-robot interaction.

Influence of Anti-TNF and Disease Modifying Antirheumatic Drugs Therapy on Pulmonary Forced Vital Capacity Associated to Ankylosing Spondylitis: A 2-Year Follow-Up Observational Study

PubMed Central

Rocha-Muñoz, Alberto Daniel; Brambila-Tapia, Aniel Jessica Leticia; Zavala-Cerna, María Guadalupe; Vásquez-Jiménez, José Clemente; De la Cerda-Trujillo, Liliana Faviola; Vázquez-Del Mercado, Mónica; Rodriguez-Jimenez, Norma Alejandra; Díaz-Rizo, Valeria; Díaz-González, Viviana; Cardona-Muñoz, Ernesto German; Dávalos-Rodríguez, Ingrid Patricia; Salazar-Paramo, Mario; Gamez-Nava, Jorge Ivan; Nava-Zavala, Arnulfo Hernan; Gonzalez-Lopez, Laura

2015-01-01

Objective. To evaluate the effect of anti-TNF agents plus synthetic disease modifying antirheumatic drugs (DMARDs) versus DMARDs alone for ankylosing spondylitis (AS) with reduced pulmonary function vital capacity (FVC%). Methods. In an observational study, we included AS who had FVC% <80% at baseline. Twenty patients were taking DMARDs and 16 received anti-TNF + DMARDs. Outcome measures: changes in FVC%, BASDAI, BASFI, 6-minute walk test (6MWT), Borg scale after 6MWT, and St. George's Respiratory Questionnaire at 24 months. Results. Both DMARDs and anti-TNF + DMARDs groups had similar baseline values in FVC%. Significant improvement was achieved with anti-TNF + DMARDs in FVC%, at 24 months, when compared to DMARDs alone (P = 0.04). Similarly, patients in anti-TNF + DMARDs group had greater improvement in BASDAI, BASFI, Borg scale, and 6MWT when compared to DMARDs alone. After 2 years of follow-up, 14/16 (87.5%) in the anti-TNF + DMARDs group achieved the primary outcome: FVC% ≥80%, compared with 11/20 (55%) in the DMARDs group (P = 0.04). Conclusions. Patients with anti-TNF + DMARDs had a greater improvement in FVC% and cardiopulmonary scales at 24 months compared with DMARDs. This preliminary study supports the fact that anti-TNF agents may offer additional benefits compared to DMARDs in patients with AS who have reduced FVC%. PMID:26078986

Clinical determinants of the 6-Minute Walk Test in bronchiectasis.

PubMed

Lee, A L; Button, B M; Ellis, S; Stirling, R; Wilson, J W; Holland, A E; Denehy, L

2009-05-01

The 6-Minute Walk Test (6MWT) is a widely used measurement of functional exercise capacity in chronic lung disease. While exercise intolerance has been identified in patients with bronchiectasis, the clinical determinants of the 6MWT in this population have not been examined. The aim of this study was to 1) establish the relationship between the 6-Minute Walk Distance (6MWD), disease severity and Health-Related Quality of Life (HRQOL) and 2) identify predictors of exercise tolerance in adults with bronchiectasis. The 6MWT was performed in 27 patients with bronchiectasis (mean [SD] FEV(1) 73.9% predicted [23.4]). Disease severity was assessed using spirometry and HRCT scoring while HRQOL was evaluated using the St George's Respiratory Questionnaire (SGRQ) and the Short-Form 36 (SF-36). The relationships were evaluated using correlation and multiple regression. The 6MWD correlated positively with FVC (r=0.52, p<0.01), generations of bronchopulmonary divisions (r(s)=0.38, p<0.05) and SF-36 physical summary (r=0.71, p<0.001) while a negative correlation was observed between all domains of the SGRQ (all correlations r>0.5, p<0.001). Multiple regression analysis indicated that the SGRQ activity, symptom scores and generations of bronchial divisions involved were identified as independent predictors of the 6MWD, explaining 76% of the variance. Measures of HRQOL demonstrated a stronger association with the 6MWD compared to physiological measures of disease severity in patients with predominantly mild to moderate bronchiectasis.

Excessive daytime sleepiness in patients on intrathecal analgesia for chronic pain.

PubMed

Demartini, Laura; Fanfulla, Francesco; Bonezzi, Cesare; Armiento, Luciana; Buonocore, Michelangelo

2015-01-01

Intrathecal (IT) drug administration is an advanced technique in pain treatment algorithm for patients poorly responsive to systemic pharmacological treatment or less invasive techniques. The aim is to improve analgesia lowering side effects; despite this premise, many side effects of long-term IT therapy have been described, mainly related to opioid administration. We observed, in some of the patients regularly followed for pump refills in our Pain Unit, the appearance of excessive daytime sleepiness (EDS) interfering with daily life and work activity; this study aims to investigate the incidence of EDS in patients on IT analgesia with opioid or non-opioid drugs and its possible relationship with respiratory problems during sleep. 21 patients on IT therapy for chronic pain answered the Epworth Sleepiness Scale (ESS). The incidence of EDS in patients receiving IT opioids was compared to a control group not receiving opioids. In 10 patients, who performed polysomnography (PSG) and maintenance of wakefulness test (MWT) for sleep complaints, we studied the relationship between PSG data and ESS scores and we verified the concordance of ESS and MWT results. 38% of the patients reported EDS, according to ESS data; all the patients with EDS were receiving an IT opioid. Even if some patients presented sleep apneas, we failed to correlate this data with daytime sleepiness. Subjective sleepiness is confirmed by the results of MWT. Our data demonstrate that EDS is a frequent and important side effect of IT analgesia and it seems related to opioids administration.

Results from the DOE Advanced Gas Reactor Fuel Development and Qualification Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

David Petti

2014-06-01

Modular HTGR designs were developed to provide natural safety, which prevents core damage under all design basis accidents and presently envisioned severe accidents. The principle that guides their design concepts is to passively maintain core temperatures below fission product release thresholds under all accident scenarios. This level of fuel performance and fission product retention reduces the radioactive source term by many orders of magnitude and allows potential elimination of the need for evacuation and sheltering beyond a small exclusion area. This level, however, is predicated on exceptionally high fuel fabrication quality and performance under normal operation and accident conditions. Germanymore » produced and demonstrated high quality fuel for their pebble bed HTGRs in the 1980s, but no U.S. manufactured fuel had exhibited equivalent performance prior to the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program. The design goal of the modular HTGRs is to allow elimination of an exclusion zone and an emergency planning zone outside the plant boundary fence, typically interpreted as being about 400 meters from the reactor. To achieve this, the reactor design concepts require a level of fuel integrity that is better than that claimed for all prior US manufactured TRISO fuel, by a few orders of magnitude. The improved performance level is about a factor of three better than qualified for German TRISO fuel in the 1980’s. At the start of the AGR program, without a reactor design concept selected, the AGR fuel program selected to qualify fuel to an operating envelope that would bound both pebble bed and prismatic options. This resulted in needing a fuel form that could survive at peak fuel temperatures of 1250°C on a time-averaged basis and high burnups in the range of 150 to 200 GWd/MTHM (metric tons of heavy metal) or 16.4 to 21.8% fissions per initial metal atom (FIMA). Although Germany has demonstrated excellent performance of TRISO-coated UO2 particle fuel up to about 10% FIMA and 1150°C, UO2 fuel is known to have limitations because of CO formation and kernel migration at the high burnups, power densities, temperatures, and temperature gradients that may be encountered in the prismatic modular HTGRs. With uranium oxycarbide (UCO) fuel, the kernel composition is engineered to prevent CO formation and kernel migration, which are key threats to fuel integrity at higher burnups, temperatures, and temperature gradients. Furthermore, the recent poor fuel performance of UO2 TRISO fuel pebbles measured in Chinese irradiation testing in Russia and in German pebbles irradiated at 1250°C, and historic data on poorer fuel performance in safety testing of German pebbles that experienced burnups in excess of 10% FIMA [1] have each raised concern about the use of UO2 TRISO above 10% FIMA and 1150°C and the degree of margin available in the fuel system. This continues to be an active area of study internationally.« less

MHD retrofit of steam power plants. Feasibility study. Summary and conclusions, Part I

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1979-07-01

The US Department of Energy Division of Magnetohydrodynamics (DOE/MHD) initiated this study to evaluate the feasibility of a retrofit option to reduce the time and cost of commercializing MHD. The MHD retrofit option will integrate a nominal 260 megawatt thermal (MWt) MHD topping cycle into an existing or scheduled private utility steam plant; this facility will test both the MHD system and the combined operation of the MHD/steam plant. The 260 MWt input level was determined to be the size which could most effectively demonstrate and verify the engineering design and operational characteristics of a coal-fired, open-cycle, MHD power plant.more » Details are presented. A goal of the MHD program is to have operational by the year 2003 a commercial size, fully integrated MHD plant. This would be accomplished by demonstrating commercial scale, baseload performance of a fully integrated, MHD/steam power plant. (WHK)« less

Influence of Different Kinds of Music on Walking in Children.

PubMed

Reychler, Gregory; Fabre, Justine; Lux, Amandine; Caty, Gilles; Pieters, Thierry; Liistro, Giuseppe

The aim of this study was to evaluate the effect of different kinds of music on submaximal performance and exercise tolerance in healthy children by means of the 6-minute walking test (6MWT) and to explore the influence of gender. Cross-over study. Ninety-seven children performed 6MWT in four conditions (without music, with their preferred music, with slow and with fast music). Distance, cardio-respiratory parameters, perceived exertion rate, and amount of dyspnea were measured. Walked distance depended on the kind of music (p = .022). To listen to fast music promoted a longer distance when compared with slow music. Walked distance was not influenced by gender (p = .721) and there was no interaction between music and gender for walked distances (p = .069). The other parameters were not modified by music and gender. Music influences submaximal performances without modifying exercise tolerance in healthy children. Music does modify submaximal performance in children.

Effects of 12-week supervised treadmill training on spatio-temporal gait parameters in patients with claudication.

PubMed

Konik, Anita; Kuklewicz, Stanisław; Rosłoniec, Ewelina; Zając, Marcin; Spannbauer, Anna; Nowobilski, Roman; Mika, Piotr

2016-01-01

The purpose of the study was to evaluate selected temporal and spatial gait parameters in patients with intermittent claudication after completion of 12-week supervised treadmill walking training. The study included 36 patients (26 males and 10 females) aged: mean 64 (SD 7.7) with intermittent claudication. All patients were tested on treadmill (Gait Trainer, Biodex). Before the programme and after its completion, the following gait biomechanical parameters were tested: step length (cm), step cycle (cycle/s), leg support time (%), coefficient of step variation (%) as well as pain-free walking time (PFWT) and maximal walking time (MWT) were measured. Training was conducted in accordance with the current TASC II guidelines. After 12 weeks of training, patients showed significant change in gait biomechanics consisting in decreased frequency of step cycle (p < 0.05) and extended step length (p < 0.05). PFWT increased by 96% (p < 0.05). MWT increased by 100% (p < 0.05). After completing the training, patients' gait was more regular, which was expressed via statistically significant decrease of coefficient of variation (p < 0.05) for both legs. No statistically significant relation between the post-training improvement of PFWT and MWT and step length increase and decreased frequency of step cycle was observed (p > 0.05). Twelve-week treadmill walking training programme may lead to significant improvement of temporal and spatial gait parameters in patients with intermittent claudication. Twelve-week treadmill walking training programme may lead to significant improvement of pain-free walking time and maximum walking time in patients with intermittent claudication.

Training on motor and visual spatial learning tasks in early adulthood produces large changes in dendritic organization of prefrontal cortex and nucleus accumbens in rats given nicotine prenatally.

PubMed

Muhammad, A; Mychasiuk, R; Hosain, S; Nakahashi, A; Carroll, C; Gibb, R; Kolb, B

2013-11-12

Experience-dependent plasticity is an ongoing process that can be observed and measured at multiple levels. The first goal of this study was to examine the effects of prenatal nicotine on the performance of rats in three behavioral tasks (elevated plus maze (EPM), Morris water task (MWT), and Whishaw tray reaching). The second goal of this experiment sought to examine changes in dendritic organization following exposure to the behavioral training paradigm and/or low doses of prenatal nicotine. Female Long-Evans rats were administered daily injections of nicotine for the duration of pregnancy and their pups underwent a regimen of behavioral training in early adulthood (EPM, MWT, and Whishaw tray reaching). All offspring exposed to nicotine prenatally exhibited substantial increases in anxiety. Male offspring also showed increased efficiency in the Whishaw tray-reaching task and performed differently than the other groups in the probe trial of the MWT. Using Golgi-Cox staining we examined the dendritic organization of the medial and orbital prefrontal cortex as well as the nucleus accumbens. Participation in the behavioral training paradigm was associated with dramatic reorganization of dendritic morphology and spine density in all brain regions examined. Although both treatments (behavior training and prenatal nicotine exposure) markedly altered dendritic organization, the effects of the behavioral experience were much larger than those of the prenatal drug exposure, and in some cases interacted with the drug effects. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

[Evaluation of an education intervention for childhood obesity prevention in basic schools in Chile].

PubMed

Lobos Fernández, Luz Lorena; Leyton Dinamarca, Bárbara; Kain Bercovich, Juliana; Vio del Río, Fernando

2013-01-01

The aim of this study was to evaluate a comprehensive intervention in nutrition education and physical activity to prevent childhood obesity in primary school children of low socioeconomic status in Macul county in Chile, with a two year follow-up (2008 and 2009) of the children. The intervention consisted in teacher nutrition training in healthy eating and the implementation of educational material based on Chilean dietary guidelines. In addition, there was an increase in physical education classes to 3-4 hours per week and physical education teachers were recruited for that purpose. Weight, height and six minutes walk test (6MWT) were measured and body mass index (BMI), BMI Z score, prevalence of normal, overweight and obese children were calculated with WHO 2007reference. Changes between baseline and BMI Z in each period and 6MWT/height, and changes in nutrition knowledge through questionnaires were measured. There was no significant difference in BMI Z score between the initial and final periods and in the evolution of the nutritional status of children. Nutrition knowledge improved significantly between the two measurements. There was a significant increase in 6MWT/height (10 meters between baseline and follow-up, p < 0.001). We conclude that although there was an improvement in nutrition knowledge and physical fitness of children, there was a stabilization of BMI Z score in the period of the study. New educational interventions are required according to the reality of each community to obtain a positive impact to prevent childhood obesity in primary schools. Copyright © AULA MEDICA EDICIONES 2013. Published by AULA MEDICA. All rights reserved.

Functional Capacity in Adults With Cerebral Palsy: Lower Limb Muscle Strength Matters.

PubMed

Gillett, Jarred G; Lichtwark, Glen A; Boyd, Roslyn N; Barber, Lee A

2018-05-01

To investigate the relation between lower limb muscle strength, passive muscle properties, and functional capacity outcomes in adults with cerebral palsy (CP). Cross-sectional study. Tertiary institution biomechanics laboratory. Adults with spastic-type CP (N=33; mean age, 25y; range, 15-51y; mean body mass, 70.15±21.35kg) who were either Gross Motor Function Classification System (GMFCS) level I (n=20) or level II (n=13). Not applicable. Six-minute walk test (6MWT) distance (m), lateral step-up (LSU) test performance (total repetitions), timed up-stairs (TUS) performance (s), maximum voluntary isometric strength of plantar flexors (PF) and dorsiflexors (DF) (Nm.kg -1 ), and passive ankle joint and muscle stiffness. Maximum isometric PF strength independently explained 61% of variance in 6MWT performance, 57% of variance in LSU test performance, and 50% of variance in TUS test performance. GMFCS level was significantly and independently related to all 3 functional capacity outcomes, and age was retained as a significant independent predictor of LSU and TUS test performance. Passive medial gastrocnemius muscle fascicle stiffness and ankle joint stiffness were not significantly related to functional capacity measures in any of the multiple regression models. Low isometric PF strength was the most important independent variable related to distance walked on the 6MWT, fewer repetitions on the LSU test, and slower TUS test performance. These findings suggest lower isometric muscle strength contributes to the decline in functional capacity in adults with CP. Copyright © 2018 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Association Between Montreal Cognitive Assessment Scores and Measures of Functional Mobility in Lower Extremity Amputees After Inpatient Rehabilitation.

PubMed

Frengopoulos, Courtney; Burley, Joshua; Viana, Ricardo; Payne, Michael W; Hunter, Susan W

2017-03-01

To determine whether scores on a cognitive measure are associated with walking endurance and functional mobility of individuals with transfemoral or transtibial amputations at discharge from inpatient prosthetic rehabilitation. Retrospective cohort study. Rehabilitation hospital. Consecutive admissions (N=176; mean age ± SD, 64.27±13.23y) with transfemoral or transtibial amputation that had data at admission and discharge from an inpatient prosthetic rehabilitation program. Not applicable. Cognitive status was assessed using the Montreal Cognitive Assessment (MoCA). The L Test and the 2-minute walk test (2MWT) were used to estimate functional mobility and walking endurance. The mean ± SD MoCA score was 24.05±4.09 (range, 6-30), and 56.3% of patients had scores <26. MoCA scores had a small positive correlation with the 2MWT (r=.29, P<.01), and a small negative correlation to the L Test (r=-.24, P<.01). In multivariable linear regression, compared with people with the highest MoCA score quartile, there was no difference on the 2MWT, but people in the lowest 2 quartiles took longer to complete the L Test. Cognitive impairment was very prevalent. The association between MoCA and functional mobility was statistically significant. These results highlight the potential for differences on complex motor tasks for individuals with cognitive impairment but does not indicate a need to exclude them from rehabilitation on the basis of cognitive impairment alone. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Barriers associated with reduced physical activity in COPD patients.

PubMed

Amorim, Priscila Batista; Stelmach, Rafael; Carvalho, Celso Ricardo Fernandes; Fernandes, Frederico Leon Arrabal; Carvalho-Pinto, Regina Maria; Cukier, Alberto

2014-10-01

To evaluate the ability of COPD patients to perform activities of daily living (ADL); to identify barriers that prevent these individuals from performing ADL; and to correlate those barriers with dyspnea severity, six-minute walk test (6MWT), and an ADL limitation score. In COPD patients and healthy, age-matched controls, the number of steps, the distance walked, and walking time were recorded with a triaxial accelerometer, for seven consecutive days. A questionnaire regarding perceived barriers and the London Chest Activity of Daily Living (LCADL) scale were used in order to identify the factors that prevent the performance of ADL. The severity of dyspnea was assessed with two scales, whereas submaximal exercise capacity was determined on the basis of the 6MWT. We evaluated 40 COPD patients and 40 controls. In comparison with the control values, the mean walk time was significantly shorter for COPD patients (68.5 ± 25.8 min/day vs. 105.2 ± 49.4 min/day; p < 0.001), as was the distance walked (3.9 ± 1.9 km/day vs. 6.4 ± 3.2 km/day; p < 0.001). The COPD patients also walked fewer steps/day. The most common self-reported barriers to performing ADL were lack of infrastructure, social influences, and lack of willpower. The 6MWT distance correlated with the results obtained with the accelerometer but not with the LCADL scale results. Patients with COPD are less active than are healthy adults of a comparable age. Physical inactivity and the barriers to performing ADL have immediate implications for clinical practice, calling for early intervention measures.

Predictors of clinical outcome in emphysema patients with atelectasis following endoscopic valve therapy: A retrospective study.

PubMed

Gompelmann, Daniela; Hofbauer, Tobias; Gerovasili, Vasiliki; Eberhardt, Ralf; Lim, Hyun-Ju; Herth, Felix; Heussel, Claus-Peter

2016-10-01

The aim of endoscopic valve therapy in patients with emphysema is complete lobar atelectasis of the most emphysematous lobe. However, even after the radiological advent of atelectasis, great variability in clinical outcomes can be observed. The baseline clinical measures (vital capacity (VC), forced expiratory flow in 1 s (FEV1 ), residual volume (RV) and 6-min walk test (6-MWT)) and computed tomography variables (low attenuation volume (LAV) of the target lobe, LAV% of the target and the ipsilateral untreated lobe and LAV of the target lobe to LAV of the target lung and to LAV of the total lung) of 77 patients with complete atelectasis following valve therapy were retrospectively examined to determine their impact on patient´s outcome (changes in VC, FEV1 , RV and 6-MWT from baseline to the time of atelectasis). Low attenuation volume of the target lobe to LAV of the target lung predicts a significant FEV1 improvement in patients with complete lobar atelectasis following valve therapy. A 10% difference in that computed tomography predictor was associated with a 82-mL improvement in FEV1 (P = 0.006). Lower 6-MWT scores, low VC and high RV at baseline were significantly associated with greater improvement in the respective parameter (all P < 0.001). Low attenuation volume of the target lobe to LAV of the target lung and baseline clinical measures seem to significantly predict clinical outcomes in patients with complete lobar atelectasis following valve treatment. © 2016 Asian Pacific Society of Respirology.

The relation of autonomic function to physical fitness in patients suffering from alcohol dependence.

PubMed

Herbsleb, Marco; Schulz, Steffen; Ostermann, Stephanie; Donath, Lars; Eisenträger, Daniela; Puta, Christian; Voss, Andreas; Gabriel, Holger W; Bär, Karl-Jürgen

2013-10-01

Reduced cardio-vascular health has been found in patients suffering from alcohol dependence. Low cardio-respiratory fitness is an independent predictor of cardio-vascular disease. We investigated physical fitness in 22 alcohol-dependent patients 10 days after acute alcohol withdrawal and compared results with matched controls. The standardized 6-min walk test (6 MWT) was used to analyze the relationship of autonomic dysfunction and physical fitness. Ventilatory indices and gas exchanges were assessed using a portable spiroergometric system while heart rate recordings were obtained separately. We calculated walking distance, indices of heart rate variability and efficiency parameters of heart rate and breathing. In addition, levels of exhaled carbon monoxide were measured in all participants to account for differences in smoking behaviour. Multivariate analyses of variance (MANOVA) were performed to investigate differences between patients and controls with regard to autonomic and efficiency parameters. Patients walked a significantly shorter distance in comparison to healthy subjects during the 6 MWT. Significantly decreased heart rate variability was observed before and after the test in patients when compared to controls, while no such difference was observed during exercise. The efficiency parameters indicated significantly reduced efficiency in physiological regulation when the obtained parameters were normalized to the distance. The 6 MWT is an easily applied instrument to measure physical fitness in alcohol dependent patients. It can also be used during exercise interventions. Reduced physical fitness, as observed in our study, might partly be caused by autonomic dysfunction, leading to less efficient regulation of physiological processes during exercise. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Association of Psychosocial Factors With Physical Activity and Function After Total Knee Replacement: An Exploratory Study.

PubMed

Dominick, Gregory M; Zeni, Joseph A; White, Daniel K

2016-09-01

To examine the association between self-efficacy, social support, and fear of movement with physical activity and function at baseline and after 12 weeks of physical therapy. Nonrandomized cohort study, repeated-measures design. Outpatient rehabilitation clinic within the general community. Adults (N=49) undergoing outpatient physical therapy for total knee replacement (TKR). Not applicable. Self-efficacy for exercise (SEE), fear of movement, leisure-time physical activity (LTPA), 6-minute walk test (6MWT), and Knee Outcome Survey-Activities of Daily Living Scale (KOS-ADLS) were assessed at baseline and 12 weeks. Mean functional change scores significantly increased at 12 weeks for the 6MWT (95% confidence interval [CI], 42.3-106.2), KOS-ADLS (95% CI, 12.7-23.3), and LTPA (95% CI, 6.5-26.1). Self-efficacy and fear of movement were not significantly associated with function at baseline or 12 weeks. Participants with lower SEE had 6 fewer metabolic equivalents per week of improvement in LTPA than those with high self-efficacy (95% CI, -27.9 to 14.8), and those with high fear of movement had 26.1m less improvement in the 6MWT than those with low fear of movement (95% CI, -42.2 to 94.5). Most participants reported having no family or peer support for exercise. Physical therapy for TKR improves physical function and self-reported physical activity. High fear of movement and low SEE may be associated with less improvement in physical activity and function over time. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Determination of exacerbation predictors in patients with COPD in physical therapy - a longitudinal study

PubMed Central

Marino, Diego M.; Marrara, Kamilla T.; Arcuri, Juliano F.; Candolo, Cecília; Jamami, Maurício; Lorenzo, Valéria A. Pires Di

2014-01-01

Background Chronic obstructive pulmonary disease (COPD) typically presents the characteristic clinical condition of exacerbation, with more intense symptoms associated with greater functional loss and consequently lower chances of patient survival. Objectives This study sought to determine the predictors of exacerbation, alone or in combination, in patients with chronic obstructive pulmonary disease (COPD) who received physical therapeutic treatment over 6 months. Method This was an observational, longitudinal and prospective study in which 63 COPD patients residing within the municipality of São Carlos, SP, Brazil were evaluated. These patients had COPD stages II and III and were entered into a physical therapy program, consisting of 3 periods of assessment over 6 months. We evaluated the occurrence of acute exacerbation as well as the patients' body mass index (BMI), fat-free mass (FFM), fat-free mass index, forced expiratory volume in 1 second (FEV1), dyspnea, distance walked (DW) in the 6-minute walk test (6MWT) and handgrip strength. Results When applying Cox settings with each covariate separately, the results revealed 5% significance only for the DW in the 6MWT, which demonstrated an interaction between BMI and FFM. Comparison of the 3 periods of assessment across the covariates measured showed a significant difference only for the DW between evaluations in the 3rd and 6th months. Conclusion Upon analyzing the predictors of risk over 6 months of follow-up in patients with COPD, we found that the DW in the 6MWT was associated with the risk of exacerbation, although this risk also depended on the covariates BMI and FFM. PMID:24845022

The validity and reliability of the ADL-Glittre test for children.

PubMed

Martins, Renata; Assumpção, Maíra S de; Bobbio, Tatiana G; Mayer, Anamaria F; Schivinski, Camila

2018-04-16

The ADL-Glittre was created to assess more comprehensively the essential activities of daily living in adults with chronic obstructive pulmonary disease. The aim of this study was to validate the ADL-Glittre test adapted for children (TGlittre-P) and verify its reliability. This is a cross-sectional study with 87 healthy children aged 6 to 14 years (mean 10.36 ± 2.32 years). Biometric and spirometry data were collected from all participants. On the same day, part of the sample (36 children included in the validation process) performed two 6MWT and two TGlittre-P (30-minute interval between them). The other part of the sample just performed two TGlittre-P for the reliability process. Pearson and Spearman correlation tests were used to verify the correlation between the time spent on the TGlittre-P and the distance walked in the 6MWT. The intraclass correlation coefficient (ICC) was also used to assess the reproducibility of the TGlittre-P. The TGlittre-P showed a moderate negative correlation with the 6MWT (r = -0.490; p = 0.002; 95%CI -0.712 to -0.233). However, the behavior of the physiological variables that were monitored during the tests was similar and showed to be reproducible (ICC = 0.843; p = 0.000; 95%CI 0.695 to 0.911). The TGlittre-P proved to be a valid and reliable assessment of the functional capacity of healthy children aged 6 to 14 years.

Benefits from the correction of vitamin D deficiency in patients with pulmonary hypertension.

PubMed

Mirdamadi, Ahmad; Moshkdar, Pouya

2016-01-01

Vitamin D (Vit D) is linked to various conditions including musculoskeletal, metabolic and cardiopulmonary diseases. However, it is not clear whether correction of vit D deficiency exerts any beneficial effect in patients with pulmonary hypertension. This study was a prospective uncontrolled longitudinal study. Patients with pulmonary hypertension and vit D deficiency were enrolled into this study. All patients in addition to standard treatment for pulmonary hypertension received cholecalciferol at a dose of 50,000 IU weekly plus calcicare (at a dose of 200 mg magnesium + 8 mg zinc + 400 IU vit D) daily for 3 months. Serum level of 25-hydroxy vit D, serum level of pro-brain natriuretic peptide, six minute walk test (6MWT), peak and mean pulmonary artery pressure, right ventricular size and function, ejection fraction (EF) and New York Heart Association (NYHA) functional class were measured at baseline and after 3 months of treatment. Twenty-two patients with pulmonary hypertension and vit D deficiency were enrolled into the study. At endpoint, the serum vit D level increased significantly to 54.8 ng/ml, the mean of baseline distance of 6MWT increased significantly to 81.6 m and the RV size significantly improved. The mean pulmonary artery pressure also improved after the intervention, but their changes did not reach to statistically significant levels. Vit D replacement therapy in patients with pulmonary arterial hypertension and vit D deficiency results in significant improvement of right ventricular size and 6 MWT. Moreover, mean pulmonary artery pressure improves nonsignificantly. This issue requires further studies with long-term follow-up period.

Additional predictive value of nutritional status in the prognostic assessment of heart failure patients.

PubMed

La Rovere, M T; Maestri, R; Olmetti, F; Paganini, V; Riccardi, G; Riccardi, R; Pinna, G D; Traversi, E

2017-03-01

Nutritional status (NS) is not routinely assessed in HF. We sought to evaluate whether NS may be additive to a comprehensive pre-discharge evaluation based on a clinical score that includes BMI (MAGGIC) and on an index of functional capacity (six minute walking test, 6mWT) in HF patients. The CONUT (Controlling Nutritional Status) score (including serum albumin level, total cholesterol and lymphocyte count) was computed in 466 consecutive patients (mean age 61 ± 11 years, NYHA class 2.6 ± 0.6, LVEF 34 ± 11%, BMI 27.2 ± 4.5) who had pre-discharge MAGGIC and 6MWT. The endpoint was all-cause mortality. Mild or moderate undernourishment was present in 54% of patients with no differences across BMI strata. The 12-month event rate was 7.7%. Deceased patients had a more compromised NS (CONUT 2.8 ± 1.5 vs 1.7 ± 1.3, p < 0.0001), and a more advanced HF (MAGGIC 28.2 ± 6.0 vs 22.0 ± 6.6, p < 0.0001; 6MWT 311.1 ± 102.2 vs. 408.9 ± 95.9 m, p < 0.0001). The 12-month mortality rate varied from 4% for well-nourished to 11% for undernourished patients (p = 0.008). At univariate analysis, the CONUT was predictive for all-cause mortality with a Hazard Ratio of 1.701 [95% CI 1.363-2.122], p < 0.0001. Multivariable analysis showed that the CONUT significantly added to the combination of MAGGIC and 6MWT and improved predictive discrimination and risk classification (c-index 0.82 [95% CI 0.75-0.88], integrated discrimination improvement 0.028 [95% CI 0.015-0.081]). In HF patients assessment of NS, significantly improves prediction of 12-month mortality on top of the information provided by clinical evaluation and functional capacity and should be incorporated in the overall assessment of HF patients. Copyright © 2016 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.

Physiological response during activity programs using Wii-based video games in patients with cystic fibrosis (CF).

PubMed

del Corral, Tamara; Percegona, Janaína; Seborga, Melisa; Rabinovich, Roberto A; Vilaró, Jordi

2014-12-01

Patients with cystic fibrosis (CF) are characterized by an abnormal ventilation response that limits the exercise capacity. Exercise training increases exercise capacity, decreases dyspnea and improves health-related quality of life in CF. Adherence to pulmonary rehabilitation programs is a key factor to guarantee optimal benefits and a difficult goal in this population. The aim of this study was to determine the physiological response during three Nintendo Wii™ video game activities (VGA) candidates to be used as training modalities in patients with CF. 24 CF patients (age 12.6±3.7 years; BMI 18.8±2.9kgm(-2); FEV1 93.8±18.8%pred) were included. All participants performed, on two separate days, 3 different VGA: 1) Wii Fit Plus (Wii-Fit); 2) Wii Active (Wii-Acti), and 3) Wii Family Trainer (Wii-Train), in random order during 5min. The obtained results were compared with the 6-min walk test (6MWT). The physiological variables [oxygen uptake (VO2), minute ventilation (VE), and heart rate (HR)] were recorded using a portable metabolic analyzer. During all VGA and 6MWT, VO2 reached a plateau from the 3rd min. Compared with the 6MWT (1024.2±282.2mLm(-1)), Wii-Acti (1232.2±427.2mLm(-1)) and Wii-Train (1252.6±360.2mLm(-1)) reached higher VO2 levels during the last 3min (p<0.0001 in both cases), while Wii-Fit (553.8±113.2mLm(-1)) reached significantly lower levels of VO2 (p<0.001). Similar effects were seen for the ventilatory volume (VE). No differences in dyspnea and oxygen saturation were seen between the different modalities. All patients were compliant with all three Wii™ modalities. Active video game are well tolerated by patients with CF. All the modalities evaluated imposed a constant load but were associated with different physiological responses reflecting the different intensities imposed. Wii-Acti and Wii-Train impose a significantly high metabolic demand comparable to the 6MWT. Further research is needed to evaluate the effects of VGA as a training program to increase exercise capacity for CF patients. Copyright © 2014 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Evaluation of functional capacity for exercise in children and adolescents with sickle-cell disease through the six-minute walk test.

PubMed

Hostyn, Sandro V; Carvalho, Werther B de; Johnston, Cíntia; Braga, Josefina A P

2013-01-01

To evaluate lung functional capacity (FC) for physical exercise in children and adolescents with sickle cell disease (SCD) through the six-minute walk test (6MWT). A cross-sectional prospective study was performed to evaluate the FC of 46 patients with SCD through the 6MWT. The following parameters were assessed: heart rate (HR), respiratory rate (RR), peripheral pulse oxygen saturation (SpO2), peak expiratory flow (PEF), blood pressure (systolic and diastolic), dyspnea, and leg fatigue (modified Borg scale) at rest, in the end of the test, and ten minutes after the 6MWT. The total distance walked was also recorded. For statistical analysis, the parametric variables were analyzed using the paired Student's t-test, analysis of variance (ANOVA), and Bonferroni multiple comparisons, with a significance level set at p ≤ 0.05. The 46 patients were aged age 9.15±3.06 years, presented baseline Hb of 9.49±1.67g/dL, and walked 480.89±68.70 m. SCD diagnosis was as follows: group 1- HbSS (n=20)/HbSβ(0)-thalassemia (n=3) and group 2 - HbSC (n=20)/HbSβ(+)-thalassemia (n=3). Regarding total distance walked, patients in group 1 walked a shorter distance than patients in group 2 (459.39±57.19 vs. 502.39±73.60 m; p=0.032). There was no statistical difference regarding PEF in the three moments of evaluation. The SpO2 in ambient air and SpO2 with O2 differed between groups 1 and 2 (p<0.001 vs. p=0.002), as well as the RR (p=0.001). These patients showed a lower FC for exercise than that predicted for the age range in the literature. Patients diagnosed with HbSS/Sβ0-thalassemia had a lower performance in the test than those with HbSC/Sβ(+)-thalassemia regarding total distance walked, RR, and SpO2 after the 6MWT. Copyright © 2013 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Objective validation of central sensitization in the rat UVB and heat rekindling model

PubMed Central

Weerasinghe, NS; Lumb, BM; Apps, R; Koutsikou, S; Murrell, JC

2014-01-01

Background The UVB and heat rekindling (UVB/HR) model shows potential as a translatable inflammatory pain model. However, the occurrence of central sensitization in this model, a fundamental mechanism underlying chronic pain, has been debated. Face, construct and predictive validity are key requisites of animal models; electromyogram (EMG) recordings were utilized to objectively demonstrate validity of the rat UVB/HR model. Methods The UVB/HR model was induced on the heel of the hind paw under anaesthesia. Mechanical withdrawal thresholds (MWTs) were obtained from biceps femoris EMG responses to a gradually increasing pinch at the mid hind paw region under alfaxalone anaesthesia, 96 h after UVB irradiation. MWT was compared between UVB/HR and SHAM-treated rats (anaesthetic only). Underlying central mechanisms in the model were pharmacologically validated by MWT measurement following intrathecal N-methyl-d-aspartate (NMDA) receptor antagonist, MK-801, or saline. Results Secondary hyperalgesia was confirmed by a significantly lower pre-drug MWT {mean [±standard error of the mean (SEM)]} in UVB/HR [56.3 (±2.1) g/mm2, n = 15] compared with SHAM-treated rats [69.3 (±2.9) g/mm2, n = 8], confirming face validity of the model. Predictive validity was demonstrated by the attenuation of secondary hyperalgesia by MK-801, where mean (±SEM) MWT was significantly higher [77.2 (±5.9) g/mm2 n = 7] in comparison with pre-drug [57.8 (±3.5) g/mm2 n = 7] and saline [57.0 (±3.2) g/mm2 n = 8] at peak drug effect. The occurrence of central sensitization confirmed construct validity of the UVB/HR model. Conclusions This study used objective outcome measures of secondary hyperalgesia to validate the rat UVB/HR model as a translational model of inflammatory pain. What's already known about this topic? Most current animal chronic pain models lack translatability to human subjects. Primary hyperalgesia is an established feature of the UVB/heat rekindling inflammatory pain model in rodents and humans, but the presence of secondary hyperalgesia, a hallmark feature of central sensitization and thus chronic pain, is contentious. What does this study add? Secondary hyperalgesia was demonstrated in the rat UVB/heat rekindling model using an objective outcome measure (electromyogram), overcoming the subjective limitations of previous behavioural studies. PMID:24590815

Voluntary driven exoskeleton as a new tool for rehabilitation in chronic spinal cord injury: a pilot study.

PubMed

Aach, Mirko; Cruciger, Oliver; Sczesny-Kaiser, Matthias; Höffken, Oliver; Meindl, Renate Ch; Tegenthoff, Martin; Schwenkreis, Peter; Sankai, Yoshiyuki; Schildhauer, Thomas A

2014-12-01

Treadmill training after traumatic spinal cord injury (SCI) has become an established therapy to improve walking capabilities. The hybrid assistive limb (HAL) exoskeleton has been developed to support motor function and is tailored to the patients' voluntary drive. To determine whether locomotor training with the exoskeleton HAL is safe and can increase functional mobility in chronic paraplegic patients after SCI. A single case experimental A-B (pre-post) design study by repeated assessments of the same patients. The subjects performed 90 days (five times per week) of HAL exoskeleton body weight supported treadmill training with variable gait speed and body weight support. Eight patients with chronic SCI classified by the American Spinal Injury Association (ASIA) Impairment Scale (AIS) consisting of ASIA A (zones of partial preservation [ZPP] L3-S1), n=4; ASIA B (with motor ZPP L3-S1), n=1; and ASIA C/D, n=3, who received full rehabilitation in the acute and subacute phases of SCI. Functional measures included treadmill-associated walking distance, speed, and time, with additional analysis of functional improvements using the 10-m walk test (10MWT), timed-up and go test (TUG test), 6-minute walk test (6MWT), and the walking index for SCI II (WISCI II) score. Secondary physiologic measures including the AIS with the lower extremity motor score (LEMS), the spinal spasticity (Ashworth scale), and the lower extremity circumferences. Subjects performed standardized functional testing before and after the 90 days of intervention. Highly significant improvements of HAL-associated walking time, distance, and speed were noticed. Furthermore, significant improvements have been especially shown in the functional abilities without the exoskeleton for over-ground walking obtained in the 6MWT, TUG test, and the 10MWT, including an increase in the WISCI II score of three patients. Muscle strength (LEMS) increased in all patients accompanied by a gain of the lower limb circumferences. A conversion in the AIS was ascertained in one patient (ASIA B to ASIA C). One patient reported a decrease of spinal spasticity. Hybrid assistive limb exoskeleton training results in improved over-ground walking and leads to the assumption of a beneficial effect on ambulatory mobility. However, evaluation in larger clinical trials is required. Copyright © 2014 Elsevier Inc. All rights reserved.

Two-dimensional polyacrylamide gel electrophoresis of bovine semen after cryopreservation in half-milliliter straws.

PubMed

Frazer, G S; Bucci, D M; Brooks, C L

1996-11-01

One of the problems encountered with two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) is the streaking of proteins so that individual spot identification is compromised. This study was conducted to determine whether a low loading dose (50 microg) of protein would permit resolution of more discrete protein spots using megapixel camera technology, and if so, to present a nomenclature for future comparisons of the identified proteins. If the major proteins could be identified in a 50-microg sample we aimed to determine whether they could be identified in the supernatant (seminal plasma plus extender) of cryopreserved semen. Two ejaculates were obtained from each of 6 bulls and bovine seminal plasma (BSP) protein concentration was standardized to 50 microg/10 microl. Isoelectric points (pI) and molecular weights (MWt) of BSP proteins were determined by measuring spot mobility on 2-D PAGE (15% polyacrylamide). Three distinct protein spot constellations (a,b,c) could be readily seen by the naked eye and a faintly stained constellation "d" was identified by the megapixel camera. The image analysis software located 6 protein spots in both constellation "a" (MWt 26 kDa; pI 4.2 to 4.8) and "b" ( MWt 27 kDa; pI 6.6 to 8.0). Constellation "c" contained 13 protein spots distributed in a right-angled triangle with its base towards the acidic end of the gel (MWt 14.7 to 18.8 kDa; pI 5.3 to 7.4). Only spots c(2), c(3), c(5), c(8), and c(13) were present in all 12 samples. Streaking can be eliminated by using 50 microg protein for 2-D PAGE, and the major protein spots are readily identified by megapixel camera technology. Protein spots c(3), c(5), c(13) and constellation "a" appear to correspond with Manjunath's proteins (BSP-A(1), -A(2); -A(3); -30 kDa). Killian's 2 low fertility proteins may lie in the "c" constellation, and 1 of the high fertility proteins may lie in the "b" constellation. The 3 major BSP proteins can be visualized in the supernatant of cryopreserved semen. We believe that the technique may prove useful for retrospective analysis of processed semen batches that achieve less than satisfactory results in the field.

Capital cost estimate

NASA Technical Reports Server (NTRS)

1975-01-01

The capital cost estimate for the nuclear process heat source (NPHS) plant was made by: (1) using costs from the current commercial HTGR for electricity production as a base for items that are essentially the same and (2) development of new estimates for modified or new equipment that is specifically for the process heat application. Results are given in tabular form and cover the total investment required for each process temperature studied.

Nuclear Engineering Computer Modules, Thermal-Hydraulics, TH-3: High Temperature Gas Cooled Reactor Thermal-Hydraulics.

ERIC Educational Resources Information Center

Reihman, Thomas C.

This learning module is concerned with the temperature field, the heat transfer rates, and the coolant pressure drop in typical high temperature gas-cooled reactor (HTGR) fuel assemblies. As in all of the modules of this series, emphasis is placed on developing the theory and demonstrating its use with a simplified model. The heart of the module…

Effects of Ramadan intermittent fasting on North African children's heart rate and oxy-haemoglobin saturation at rest and during sub-maximal exercise.

PubMed

Fenneni, Mohamed Amine; Latiri, Imed; Aloui, Asma; Rouatbi, Sonia; Chamari, Karim; Saad, Helmi Ben

To examine the effects of Ramadan intermittent fasting (RIF) on the heart rate (HR) and oxyhaemoglobin saturation levels (oxy-sat) of boys at rest and during a six-minute walking test (6MWT). Eighteen boys (age: 11.9 ± 0.8 years, height: 153.00 ± 8.93 cm, body mass: 55.4 ± 18.2 kg), who fasted the entire month of Ramadan in 2012 for the first time in their lives, were included. The experimental protocol comprised four testing phases: two weeks before Ramadan (pre-R), the end of the second week of Ramadan (R-2), the end of the fourth week of Ramadan (R-4), and 10 to 12 days after the end of Ramadan (post-R). During each phase, participants performed the 6MWT at approximately 15:00. HR (expressed as percentage of maximal predicted HR) and oxy-sat (%) were determined at rest and in each minute of the 6MWT. R-4 HR values were lower than those of (1) pre-R (in the second minute), (2) R-2 (in the first and second minutes), and (3) post-R (in the first, second, fourth, fifth and sixth minutes). R-2 oxy-sat values were higher than those of pre-R (in the third minute) and those of post-R (in the fifth minute). Post-R oxy-sat values were lower than those of pre-R and R-4 in the fifth minute. These oxy-sat changes were not clinically significant since the difference was less than five points. In non-athletic children, their first RIF influenced their heart rate data but had a minimal effect on oxy-sat values.

Comparison of the Mini-Balance Evaluations Systems Test with the Berg Balance Scale in relationship to walking speed and motor recovery post stroke.

PubMed

Madhavan, Sangeetha; Bishnoi, Alka

2017-12-01

The Mini-BESTest is a recently developed balance assessment tool that incorporates challenging dynamic balance tasks. Few studies have compared the psychometric properties of the Mini-BESTest to the commonly used Berg Balance Scale (BBS). However, the utility of these scales in relationship to post stroke walking speeds has not been explored. The purpose of this study was to compare the sensitivity and specificity of the Mini-BESTest and BBS to evaluate walking speeds in individuals with stroke. A retrospective exploratory design. Forty-one individuals with chronic stroke were evaluated with the Mini-BESTest, BBS, and 10-meter self-selected walk test (10MWT). Based on their self-selected gait speeds (below or above 0.8 m/s), participants were classified as slow and fast walkers. Significant linear correlations were observed between the Mini-BESTest vs. BBS (r = 0.72, p ≤ 0.001), Mini-BESTest vs. 10MWT (r = 0.58, p ≤ 0.001), and BBS vs. 10MWT (r = 0.30, p = 0.05). Independent t-tests comparing the balance scores for the slow and fast walkers revealed significant group differences for the Mini-BESTest (p = 0.003), but not for the BBS (p = 0.09). The Mini-BESTest demonstrated higher sensitivity (93%) and specificity (64%) compared to the BBS (sensitivity 81%, specificity 56%) for discriminating participants into slow and fast walkers. The Mini-BESTest has a greater discriminative ability than the BBS to categorize individuals with stroke into slow and fast walkers.

Comparison of the Mini-Balance Evaluations Systems Test with the Berg Balance Scale in relationship to walking speed and motor recovery post stroke

PubMed Central

Madhavan, Sangeetha; Bishnoi, Alka

2017-01-01

Background The Mini-BESTest is a recently developed balance assessment tool that incorporates challenging dynamic balance tasks. Few studies have compared the psychometric properties of the Mini-BESTest to the commonly used Berg Balance Scale (BBS). However, the utility of these scales in relationship to post stroke walking speeds has not been explored. Objectives The purpose of this study was to compare the sensitivity and specificity of the Mini-BESTest and BBS to evaluate walking speeds in individuals with stroke. Design A retrospective exploratory design. Methods Forty-one individuals with chronic stroke were evaluated with the Mini-BESTest, BBS, and 10-meter self-selected walk test (10MWT). Based on their self-selected gait speeds (below or above 0.8 m/s), participants were classified as slow and fast walkers. Results Significant linear correlations were observed between the Mini-BESTest vs. BBS (r = 0.72, p ≤ 0.001), Mini-BESTest vs. 10MWT (r = 0.58, p ≤ 0.001), and BBS vs. 10MWT (r = 0.30, p = 0.05). Independent t-tests comparing the balance scores for the slow and fast walkers revealed significant group differences for the Mini-BESTest (p =0.003), but not for the BBS (p = 0.09). The Mini-BESTest demonstrated higher sensitivity (93%) and specificity (64%) compared to the BBS (sensitivity 81%, specificity 56%) for discriminating participants into slow and fast walkers. No significant results were observed with the FMLE-M scores. Conclusions The Mini-BESTest has a greater discriminative ability than the BBS to categorize individuals with stroke into slow and fast walkers. PMID:28826325

Submaximal Exercise Capacity in Juvenile Dermatomyositis after Longterm Disease: The Contribution of Muscle, Lung, and Heart Involvement.

PubMed

Berntsen, Kristin Schjander; Tollisen, Anita; Schwartz, Thomas; Kirkhus, Eva; Aaløkken, Trond Mogens; Lund, May Brit; Flatø, Berit; Sjaastad, Ivar; Sanner, Helga

2017-06-01

To compare submaximal exercise capacity in patients with juvenile dermatomyositis (JDM) with controls, and analyze contributions of muscle, heart, and lung impairment in patients. Fifty-nine patients with JDM, with a mean 16.9 years after symptom onset, and 59 sex- and age-matched controls completed a 6-min walk test (6MWT) and a timed up and go (TUG) test. Muscle function, disease activity/damage, and health-related quality of life (HRQOL) were assessed by validated tools; heart function by echocardiography and electrocardiography; and lung function by spirometry, DLCO, and body plethysmography. A thoracic high-resolution computed tomography (HRCT) scan and magnetic resonance imaging of the thighs were completed in patients. The 6MWT distance (6MWD) was 592 ± 81 m in patients versus 649 ± 79 m in controls (p < 0.001), and 563 ± 75 m in active versus 622 ± 76 m in inactive JDM (p = 0.004). The TUG time was 13.1 ± 2.1 s in patients versus 12.3 ± 2.0 s in controls (p = 0.034), and 13.7 ± 2.2 s in active versus 12.5 ± 1.8 s in inactive JDM (p = 0.028). No statistically significant difference was found between inactive JDM and controls in either test. In patients, the Childhood Myositis Assessment Score influenced the 6MWD and TUG time the most, followed by a low DLCO and HRCT pathology in the 6MWT and forced vital capacity in the TUG test. Medical Outcomes Study Short Form-36 physical component summary correlated strongly with both tests. Submaximal exercise capacity was reduced in patients with JDM, particularly those with active disease. This reduction was associated with muscle and lung dysfunction and poorer HRQOL.

Reference Values for the 6-min Walk Distance in Healthy Children Age 7 to 12 Years in Brazil: Main Results of the TC6minBrasil Multi-Center Study.

PubMed

de Assis Pereira Cacau, Lucas; Carvalho, Vitor Oliveira; Dos Santos Pin, Alessandro; Araujo Daniel, Carlos Raphael; Ykeda, Daisy Satomi; de Carvalho, Eliane Maria; Francica, Juliana Valente; Faria, Luíza Martins; Gomes-Neto, Mansueto; Fernandes, Marcelo; Velloso, Marcelo; Karsten, Marlus; de Sá Barros, Patrícia; de Santana-Filho, Valter Joviniano

2018-03-01

Brazil is a country with great climatic, socioeconomic, and cultural differences that does not yet have a reference value for the 6-min walk test (6MWT) in healthy children. To avoid misinterpretation, the use of equations to predict the maximum walk distance should be established in each country. We sought to establish reference values and to develop an equation to predict the 6-min walk distance for healthy children in Brazil. This is a cross-sectional multi-center study that included 1,496 healthy children, aged 7 to 12 y, assessed across 11 research sites in all regions of Brazil, and recruited from public and private schools in their respective regions. Each child was assessed for weight and height. Walk distance was our main outcome. An open-source software environment for statistical computing was used for statistical analysis. We observed a higher average distance walked by boys (531.1 m) than by girls (506.2 m), with a difference of 24.9 m ( P < .001). We established 6MWT reference values for boys with the following equation: Distance = (16.86 × age) + (1.89 × Δ heart rate) - (0.80 × weight) + (336.91 × R1) + (360.91 × R2). For girls the equation is as follows: Distance = (13.54 × age) + (1.62 × Δ heart rate) - (1.28 × weight) + (352.33 × R1) + (394.81 × R2). Reference values were established for the 6MWT in healthy children aged 7-12 y in Brazil. Copyright © 2018 by Daedalus Enterprises.

The six-minute walk test predicts cardiorespiratory fitness in individuals with aneurysmal subarachnoid hemorrhage.

PubMed

Harmsen, Wouter J; Ribbers, Gerard M; Slaman, Jorrit; Heijenbrok-Kal, Majanka H; Khajeh, Ladbon; van Kooten, Fop; Neggers, Sebastiaan J C M M; van den Berg-Emons, Rita J

2017-05-01

Peak oxygen uptake (VO 2peak ) established during progressive cardiopulmonary exercise testing (CPET) is the "gold-standard" for cardiorespiratory fitness. However, CPET measurements may be limited in patients with aneurysmal subarachnoid hemorrhage (a-SAH) by disease-related complaints, such as cardiovascular health-risks or anxiety. Furthermore, CPET with gas-exchange analyses require specialized knowledge and infrastructure with limited availability in most rehabilitation facilities. To determine whether an easy-to-administer six-minute walk test (6MWT) is a valid clinical alternative to progressive CPET in order to predict VO 2peak in individuals with a-SAH. Twenty-seven patients performed the 6MWT and CPET with gas-exchange analyses on a cycle ergometer. Univariate and multivariate regression models were made to investigate the predictability of VO 2peak from the six-minute walk distance (6MWD). Univariate regression showed that the 6MWD was strongly related to VO 2peak (r = 0.75, p < 0.001), with an explained variance of 56% and a prediction error of 4.12 ml/kg/min, representing 18% of mean VO 2peak . Adding age and sex to an extended multivariate regression model improved this relationship (r = 0.82, p < 0.001), with an explained variance of 67% and a prediction error of 3.67 ml/kg/min corresponding to 16% of mean VO 2peak . The 6MWT is an easy-to-administer submaximal exercise test that can be selected to estimate cardiorespiratory fitness at an aggregated level, in groups of patients with a-SAH, which may help to evaluate interventions in a clinical or research setting. However, the relatively large prediction error does not allow for an accurate prediction in individual patients.

Changes in pulmonary function and functional capacity in adolescents with mild idiopathic scoliosis: observational cohort study

PubMed Central

Abdelaal, Ashraf Abdelaal Mohamed; Abd El Kafy, Ehab Mohamed Abo El Soad; Elayat, Mohamed Salah Eldien Mohamed; Sabbahi, Mohamed; Badghish, Mohamed Salem Saed

2017-01-01

Objective This observational cohort study aimed to evaluate ventilatory function (VF) and functional exercise capacity (FEC) in mild adolescent idiopathic scoliosis (AIS). Methods Seventy-three adolescents with idiopathic scoliosis, aged approximately 10 to 17 years (mean age: 13.43 ± 1.27 years), with a Cobb angle less than 20° (mean: 16.44° ± 1.59°), met the inclusion criteria and were assigned to group A. Another 34 healthy adolescents with normal VF and FEC served as controls (group B). Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), maximum voluntary ventilation (MVV), and FEC (by the 6-minute walk test [6MWT]) were the main outcome measures. Results Post-study mean values of FVC, FEV1, FEV1/FVC, MVV, and the 6MWT were 2.42 ± 0.36 L and 3.26 ± 0.59 L, 2.14 ± 0.31 L and 3.03 ± 0.43 L, 88.13% ± 3.89% and 91.14% ± 4.67%, 76.96 ± 6.85 L/m and 107.61 ± 11.44 L/m, and 581.12 ± 12.25 m and 627.74 ± 15.27 m in groups A and B, respectively. Between-group comparisons showed significant differences in FVC, FEV1, FEV1/FVC, MVV, and the 6MWT. Conclusion Mild pulmonary and functional restrictions start early in mild AIS. This issue requires immediate intervention to prevent further deterioration. PMID:28661261

Comparison of Predictors of Heart Failure-related Hospitalization or Death in Patients with versus without Preserved Left Ventricular Ejection Fraction

PubMed Central

Mangla, Ashvarya; Kane, John; Beaty, Elijah; Richardson, DeJuran; Powell, Lynda H.; Calvin, James E.

2013-01-01

Heart failure with preserved ejection fraction (HFpEF) is recognized as a major cause of cardiovascular morbidity and mortality. An ability to identify patients with HFpEF who are at increased risk for adverse outcome can facilitate their more careful management. We studied the patients having heart failure (HF) using data from the Heart Failure Adherence and Retention Trial (HART). HART enrolled 902 NYHA Class II or III patients who had been recently hospitalized for HF to study the impact of self-management counseling on the primary outcome of death or HF hospitalization. In HART 208 patients had HFpEF and 692 had HFrEF (heart failure with reduced ejection fraction), and were followed for median of 1080 days. Two final multivariate models were developed. In patients having HFpEF, predictors of primary outcome were: male sex (OR 3.45, p=0.004), NYHA class III (OR 3.05, p=0.008), distance covered on 6-minute walk test (6-MWT) of< 620 feet (OR 2.81, p=0.013), and <80% adherence to prescribed medications (OR 2.61, p=0.018). In patients having HFrEF, the predictors were: being on diuretics (OR 3.06, p=0.001), having ≥ 3 comorbidities (OR 2.11, p=0.0001), distance covered on 6-MWT of < 620 feet (OR 1.94, p=0.001), NYHA class III (OR 1.90, p=0.001) and age > 65 years (OR 1.63, p=0.01). In conclusion, indicators of functional status(6-MWT and NYHA class) were common to both HFpEF and HFrEF patients while gender and adherence to prescribed therapy were unique to patients having HFpEF in predicting death or HF hospitalization. PMID:24063842

No effect of group-based aerobic interval training on N-terminal pro- B-type natriuretic peptide levels in patients with chronic heart failure.

PubMed

Nilsson, Birgitta Blakstad; Westheim, Arne; Risberg, May Arna; Arnesen, Harald; Seljeflot, Ingebjørg

2010-08-01

Exercise training might improve cardiac function as well as functional capacity in patients with chronic heart failure (CHF). N-terminal pro-B-type natriuretic peptide (NT pro-BNP), is associated with the severity of the disease, and has been reported to be an independent predictor of outcome in CHF. We evaluated the effect of a four months group-based aerobic interval training program on circulating levels of NT pro-BNP in patients with CHF. We have previously reported improved functional capacity in 80 patients after exercise in this exercise program. Seventy-eight patients with stable CHF (21% women; 70+/-8 years; left ventricular ejection fraction 30+/-8.6%) on optimal medical treatment were randomized either to interval training (n=39), or to a control group (n=39). Circulating levels of NT pro-BNP, a six minute walk test (6MWT) and cycle ergometer test were evaluated at baseline, post exercise, and further after 12 months. There were no significant differences in NT pro-BNP levels from baseline to either post exercise or long-term follow-up between or within the groups. Inverse correlations were observed between NT pro-BNP and 6MWT (r=-0.24, p=0.035) and cycle exercise time (r=-0.48, p<0.001) at baseline. But no significant correlations were observed between change in NT pro-BNP and change in functional capacity (6MWT; r=0.12, p=0.33, cycle exercise time; r=0.04, p=0.72). No significant changes in NT pro-BNP levels were observed after interval training, despite significant improvement of functional capacity.

Relevance of physical fitness levels and exercise-related beliefs for self-reported and experimental pain in fibromyalgia: an explorative study.

PubMed

de Bruijn, Saskia T; van Wijck, Albert J M; Geenen, Rinie; Snijders, Tom J; van der Meulen, Wout J T M; Jacobs, Johannes W G; Veldhuijzen, Dieuwke Swaantje

2011-09-01

It has been suggested that low physical fitness is a contributor to pain in fibromyalgia and that exercise-related beliefs play a role in the persistence of this association. Yet the association between physical fitness and pain is hardly explored in detail. The aim of this exploratory study in patients with fibromyalgia was to investigate the association of physical fitness levels with self-reported and experimental pain as well as with pain catastrophizing and activity-avoidance beliefs. Physical fitness of 18 patients with fibromyalgia was examined using maximal ergocycling and the 6-minute walking test (6MWT). Pain intensity was assessed using self-report scales and quantitative sensory testing. A reduced walking distance on the 6MWT was correlated with more severe self-reported pain on the Fibromyalgia Impact Questionnaire (r = -0.52, P < 0.05). Recovery of heart rate after ergocycling was correlated with cold pain thresholds (r = 0.70, P < 0.01), pressure pain thresholds (r = -0.70, P < 0.01), and heat wind-up (r = 0.66, P < 0.05). Activity-avoidance beliefs correlated with a lower peak VO2 on the cycle test (r = -0.52, P < 0.05), a shorter distance on the 6MWT (r = -0.56, P < 0.05), and more severe self-reported pain (r = 0.61, P < 0.05), reflecting that patients with activity-avoidance beliefs were less physically fit and experienced more severe pain. The results demonstrate some associations between physical fitness and pain in fibromyalgia and point to the importance of activity avoidance. Although the causal directionality of the associations needs substantiation in clinical research, the findings support the notion that low fitness and activity-avoidance beliefs should be targeted while treating pain in fibromyalgia.

Responsiveness and Minimally Important Difference of the 6-Minute Stepper Test in Patients with Chronic Obstructive Pulmonary Disease.

PubMed

Pichon, Romain; Couturaud, Francis; Mialon, Philippe; Le Ber-Moy, Catherine; Péran, Loïc; Lochon, Chantal; Nowak, Emmanuel; Beaumont, Marc

2016-01-01

The validity and reproducibility of the 6-minute stepper test (6MST) have already been demonstrated in patients with chronic obstructive pulmonary disease (COPD). The aim of this study was to evaluate the responsiveness of the 6MST to pulmonary rehabilitation (PR) in patients with COPD, to determine a minimal important difference (MID) for the 6MST, and to compare the 6MST and the 6-minute walk test (6MWT). Sixty-two patients with COPD were included in a prospective experimental study. Participants underwent a 3-week inpatient PR program. The primary outcome was the change in the number of steps during the 6MST measured before and after PR. The secondary outcome included the change in the 6-minute walking distance (6MWD) pulse oximetry, heart rate, dyspnea, and leg discomfort during the tests measured before and after PR. MID was determined by anchor-based and distribution approaches. After PR, we observed a significant increase in the number of steps during the 6MST (22.5 steps; 95% CI 13.8-31.3; p < 0.0001) and in the 6MWD (26.6 m; 95% CI 17.6-35.5; p < 0.0001). The 6MST and 6MWT were improved by 10.1 and 6.5%, respectively. The number of steps during the 6MST was significantly correlated with the 6MWD before (r = 0.72; p < 0.0001) and after PR (r = 0.66; p < 0.0001). MID was estimated to be around 20 steps. The 6MST appears to be as responsive as the 6MWT in assessing functional improvement during PR in patients with COPD. The 6MST is a low-cost assessment and requires limited space. © 2016 S. Karger AG, Basel.

Two 6-minute Walk Tests Are Required During Hospitalisation for Acute Exacerbation of COPD.

PubMed

Osadnik, Christian R; Borges, Rodrigo C; McDonald, Christine F; Carvalho, Celso R F; Holland, Anne E

2016-06-01

The 6-minute walk test (6MWT) is recommended to be performed twice to accurately assess exercise performance in stable chronic obstructive pulmonary disease (COPD) due to the presence of a learning effect. It is unknown whether a learning effect exists when the 6MWT is performed during hospitalisation for acute exacerbation of COPD (AECOPD). This study investigated whether repeat 6MWTs are necessary when conducted in inpatients with AECOPD. Pooled analysis was undertaken of data from two studies (Australia and Brazil) involving 46 participants (25 males, mean age 67.2 years, FEV1 43% predicted) admitted with AECOPD. Two 6MWTs, separated by ≥20 minutes, were performed on the day of discharge. Six-minute walk distance (6MWD; primary outcome), perceived dyspnoea (Borg scale), heart rate and oxyhaemoglobin saturation were recorded. 6MWD data from tests one (T1) and two (T2) were analysed via visual inspection of Bland-Altman plots. Factors associated with test improvement or decline were explored. Mean 6MWD difference between T1 and T2 was 6.2 m, however limits of agreement were wide (-92.2 m to 104.5 m). 32 (70%) participants improved (by any distance) from T1 to T2 by a mean (± standard deviation) of 32 m ± 28 m. Of these, 14 (30%) improved by a distance > 30 m. Fourteen (30%) participants recorded poorer 6MWD at T2 by a mean of 52 m ± 36 m. No factors were able to identify participants who improved or declined upon repeat testing. When performed in patients admitted to hospital with AECOPD, the 6MWT needs to be conducted twice in order to better estimate 6MWD.

Long-term effects of oxygen-enriched high-flow nasal cannula treatment in COPD patients with chronic hypoxemic respiratory failure.

PubMed

Storgaard, Line Hust; Hockey, Hans-Ulrich; Laursen, Birgitte Schantz; Weinreich, Ulla Møller

This study investigated the long-term effects of humidified high-flow nasal cannula (HFNC) in COPD patients with chronic hypoxemic respiratory failure treated with long-term oxygen therapy (LTOT). A total of 200 patients were randomized into usual care ± HFNC. At inclusion, acute exacerbation of COPD (AECOPD) and hospital admissions 1 year before inclusion, modified Medical Research Council (mMRC) score, St George's Respiratory Questionnaire (SGRQ), forced expiratory volume in 1 second (FEV 1 ), 6-minute walk test (6MWT) and arterial carbon dioxide (PaCO 2 ) were recorded. Patients completed phone interviews at 1, 3 and 9 months assessing mMRC score and AECOPD since the last contact. At on-site visits (6 and 12 months), mMRC, number of AECOPD since last contact and SGRQ were registered and FEV 1 , FEV 1 %, PaCO 2 and, at 12 months, 6MWT were reassessed. Hospital admissions during the study period were obtained from hospital records. Hours of the use of HFNC were retrieved from the high-flow device. The average daily use of HFNC was 6 hours/day. The HFNC group had a lower AECOPD rate (3.12 versus 4.95/patient/year, p <0.001). Modeled hospital admission rates were 0.79 versus 1.39/patient/year for 12- versus 1-month use of HFNC, respectively ( p <0.001). The HFNC group had improved mMRC scores from 3 months onward ( p <0.001) and improved SGRQ at 6 and 12 months ( p =0.002, p =0.033) and PaCO 2 ( p =0.005) and 6MWT ( p =0.005) at 12 months. There was no difference in all-cause mortality. HFNC treatment reduced AECOPD, hospital admissions and symptoms in COPD patients with hypoxic failure.

Endothelin-1–Rho kinase interactions impair lung structure and cause pulmonary hypertension after bleomycin exposure in neonatal rat pups

PubMed Central

Tseng, Nancy; Seedorf, Gregory; Kuhn, Katherine; Abman, Steven H.

2016-01-01

Bronchopulmonary dysplasia (BPD) is the chronic lung disease associated with premature birth, characterized by impaired vascular and alveolar growth. In neonatal rats bleomycin decreases lung growth and causes pulmonary hypertension (PH), which is poorly responsive to nitric oxide. In the developing lung, through Rho kinase (ROCK) activation, ET-1 impairs endothelial cell function; however, whether ET-1–ROCK interactions contribute to impaired vascular and alveolar growth in experimental BPD is unknown. Neonatal rats were treated daily with intraperitoneal bleomycin with and without selective ETA (BQ123/BQ610) and ETB (BQ788) receptor blockers, nonselective ET receptor blocker (ETRB) (bosentan), or fasudil (ROCK inhibitor). At day 14, lungs were harvested for morphometrics, and measurements of Fulton's index (RV/LV+S), medial wall thickness (MWT), and vessel density. Lung ET-1 protein and ROCK activity (phospho-MYPT-1:total MYPT-1 ratio) were also measured by Western blot analysis. Bleomycin increased lung ET-1 protein expression by 65%, RV/LV+S by 60%, mean linear intercept (MLI) by 212%, and MWT by 140% and decreased radial alveolar count (RAC) and vessel density by 40 and 44%, respectively (P < 0.01 for each comparison). After bleomycin treatment, fasudil and bosentan partially restored RAC and vessel density and decreased MLI, RV/LV+S, and MWT to normal values. Bleomycin increased ROCK activity by 120%, which was restored to normal values by bosentan but not selective ETRB. We conclude that ET-1–ROCK interactions contribute to decreased alveolar and vascular growth and PH in experimental BPD. We speculate that nonselective ETRB and ROCK inhibitors may be effective in the treatment of infants with BPD and PH. PMID:27760762

Endothelin-1-Rho kinase interactions impair lung structure and cause pulmonary hypertension after bleomycin exposure in neonatal rat pups.

PubMed

Gien, Jason; Tseng, Nancy; Seedorf, Gregory; Kuhn, Katherine; Abman, Steven H

2016-12-01

Bronchopulmonary dysplasia (BPD) is the chronic lung disease associated with premature birth, characterized by impaired vascular and alveolar growth. In neonatal rats bleomycin decreases lung growth and causes pulmonary hypertension (PH), which is poorly responsive to nitric oxide. In the developing lung, through Rho kinase (ROCK) activation, ET-1 impairs endothelial cell function; however, whether ET-1-ROCK interactions contribute to impaired vascular and alveolar growth in experimental BPD is unknown. Neonatal rats were treated daily with intraperitoneal bleomycin with and without selective ET A (BQ123/BQ610) and ET B (BQ788) receptor blockers, nonselective ET receptor blocker (ETRB) (bosentan), or fasudil (ROCK inhibitor). At day 14, lungs were harvested for morphometrics, and measurements of Fulton's index (RV/LV+S), medial wall thickness (MWT), and vessel density. Lung ET-1 protein and ROCK activity (phospho-MYPT-1:total MYPT-1 ratio) were also measured by Western blot analysis. Bleomycin increased lung ET-1 protein expression by 65%, RV/LV+S by 60%, mean linear intercept (MLI) by 212%, and MWT by 140% and decreased radial alveolar count (RAC) and vessel density by 40 and 44%, respectively (P < 0.01 for each comparison). After bleomycin treatment, fasudil and bosentan partially restored RAC and vessel density and decreased MLI, RV/LV+S, and MWT to normal values. Bleomycin increased ROCK activity by 120%, which was restored to normal values by bosentan but not selective ETRB. We conclude that ET-1-ROCK interactions contribute to decreased alveolar and vascular growth and PH in experimental BPD. We speculate that nonselective ETRB and ROCK inhibitors may be effective in the treatment of infants with BPD and PH. Copyright © 2016 the American Physiological Society.

Respiratory muscle impairment in dialysis patients: can minimal dose of exercise limit the damage? A Preliminary study in a sample of patients enrolled in the EXCITE trial.

PubMed

Pomidori, Luca; Lamberti, Nicola; Malagoni, Anna Maria; Manfredini, Fabio; Pozzato, Enrico; Felisatti, Michele; Catizone, Luigi; Barillà, Antonio; Zuccalà, Alessandro; Tripepi, Giovanni; Mallamaci, Francesca; Zoccali, Carmine; Cogo, Annalisa

2016-12-01

Skeletal muscle atrophy and dysfunction with associated weakness may involve the respiratory muscles of dialysis patients. We evaluated the effect of moderate-intensity exercise on lung function and respiratory muscle strength. Fifty-nine patients (25 F, aged 65 ± 13 years) from two centers participating in the multicenter randomized clinical trial EXerCise Introduction To Enhance Performance in Dialysis (EXCITE) were studied. Subjects were randomized into a prescribed exercise group (E), wherein subjects performed two 10-min walking sessions every second day at an intensity below the self-selected speed, or a control group (C) with usual care. Physical performance was assessed by the 6-min walk test (6MWT). Patient lung function and respiratory muscle strength were evaluated by spirometry and maximal inspiratory pressure (MIP), respectively. Forty-two patients (14 F) completed the study. At baseline, the groups did not differ in any parameters. In total, 7 patients (4 in E; 3 in C) showed an obstructive pattern. The pulmonary function parameters were significantly correlated with 6MWT but not with any biochemical measurements. Group E safely performed the exercise program. At follow-up, the spirometry parameters did not change in either group. A deterioration of MIP (-7 %; p = 0.008) was observed in group C, but not in group E (+3.3 %, p = ns). In E, an increase of 6MWT was also found (+12 vs. 0 % in C; p = 0.038). In dialysis patients, a minimal dose of structured exercise improved physical capacity and maintained a stable respiratory muscle function, in contrast to the control group where it worsened.

Socializing by Day May Affect Performance by Night: Vulnerability to Sleep Deprivation is Differentially Mediated by Social Exposure in Extraverts vs Introverts.

PubMed

Rupp, Tracy L; Killgore, William D S; Balkin, Thomas J

2010-11-01

to examine the effects of socially enriched versus socially impoverished environments on performance and alertness decline during sleep deprivation in extraverts versus introverts. participants (n = 29 men, n = 19 women) were assigned to socially enriched (n = 24; 13 introverts, 11 extraverts) or socially impoverished (n = 24; 12 introverts, 12 extraverts) conditions (activities matched) for 12 hours (1000-2200) on Day 1 followed by 22 hours of sleep deprivation (2200-2000; 36 h awake total), monitored by actigraphy. The median split of volunteers' Eysenck Extraversion scores was used for extravert/introvert categorization. The Psychomotor Vigilance Task (PVT), modified Maintenance of Wakefulness Test (MWT), and Stanford Sleepiness Scale (SSS) were administered every 2 hours throughout. PVT speed, transformed lapses, modified MWT sleep-onset latency, and SSS were analyzed using mixed-model analyses of variance, with covariates of age and total actigraphic activity during enrichment or impoverishment. residential sleep/performance testing facility. forty-eight healthy adults (aged 18-39). Twelve hours of socially enriched or isolated environments in extraverts and introverts prior to sleep deprivation. Social experience interacted with personality type to affect alertness and vigilance. Social enrichment, as compared with social impoverishment, was associated with more PVT lapses at 04:00 overall. Similarly, following social enrichment, PVT speed was significantly slower among extraverts than among introverts during sleep deprivation, but no personality-group differences emerged following social impoverishment. MWT sleep latency and SSS subjective sleepiness did not show significant personality or social-condition effects during sleep deprivation. the effect of social exposure on vulnerability or resiliency to sleep deprivation was modulated by introversion and extraversion. Extraverts exposed to social environments were more vulnerable to subsequent sleep deprivation than were introverts.

The immediate and long-term effects of a walking-skill program compared to usual physiotherapy care in patients who have undergone total knee arthroplasty (TKA): a randomized controlled trial.

PubMed

Bruun-Olsen, Vigdis; Heiberg, Kristi Elisabeth; Wahl, Astrid Klopstad; Mengshoel, Anne Marit

2013-01-01

To examine the immediate and long-term effects of a walking-skill program compared with usual physiotherapy on physical function, pain and perceived self-efficacy in patients after total knee arthroplasty (TKA). A single blind randomized controlled trial design was applied. Fifty-seven patients with primary TKA, mean age of 69 years (SD ± 9), were randomly assigned to a walking-skill program emphasizing weight-bearing exercises or usual physiotherapy. Outcomes were assessed before the interventions started at 6 weeks postoperatively (T1), directly after the interventions at 12-14 weeks (T2) and 9 months after the interventions (T3). Walking was the primary outcome, assessed by the 6 min walk test (6MWT). The secondary outcomes were timed stair climbing, timed stands, Figure-of-eight test, Index of muscle function, active knee range of motion, Knee Injury and Osteoarthritis Outcome Score and self-efficacy score. From T1 to T2, a better 6MWT score was found in favor of the walking-skill program of 39 m (2-76), p = 0.04. The difference between the groups in 6MWT persisted at T3, 44 m (8-80), p = 0.02. No differences in other outcome measures were found. The walking-skill program had better effect on walking than usual physiotherapy. Weight bearing was tolerated. Implications for Rehabilitation Weight-bearing exercises are tolerated by the patients in the early stage after TKA. Physiotherapy that focuses on learning different ways of walking through practice may be a plausible way to train patients after TKA.

Comparison of mobility and user satisfaction between a microprocessor knee and a standard prosthetic knee: a summary of seven single-subject trials.

PubMed

Howard, Charla L; Wallace, Chris; Perry, Bonnie; Stokic, Dobrivoje S

2018-03-01

Insufficient evidence of the benefits provided by costlier microprocessor knees (MPKs) over nonmicroprocessor knees (NMPKs) often causes concern when considering MPK prescription. Thus, more studies are needed to demonstrate differences between MPKs and NMPKs and define sensitive outcomes to guide MPK prescription. The aim of this study was to evaluate the impact of switching from NMPK to MPK on measures of mobility and preference. Seven long-term NMPK users (all men, ages 50-84, 3-64 years postamputation) participated in this study, which use a single-subject design (ABA or BAB; A=NMPK, B=MPK). Mobility was assessed with the Amputee Mobility Predictor, Berg Balance Scale (BBS), L-Test, 6-Min Walk Test (6MWT) with Physiological Cost Index, and self-selected normal and very fast gait speeds. The preference between NMPK and MPK was evaluated by the Prosthesis Evaluation Questionnaire (PEQ) and the visual analog scale. Mobility improved with the MPK in six of seven participants, which was most often captured with BBS (median: +6 points) and 6MWT (median: +63 m). These improvements typically exceeded minimal clinically important difference or minimal detectable change thresholds. Most participants scored the MPK higher on the PEQ (median: +20 points) and six of seven expressed a global preference toward MPK. In the BAB group, the Amputee Mobility Predictor and BBS correlated with perception of change on several PEQ domains (Ρ≥0.59). In conclusion, MPKs may provide better outcomes and user satisfaction, particularly in those with lower mobility function. BBS and 6MWT were found to be the most sensitive measures to capture changes in mobility while using MPK for several weeks.

Effects of Virtual Reality Training using Xbox Kinect on Motor Function in Stroke Survivors: A Preliminary Study.

PubMed

Park, Dae-Sung; Lee, Do-Gyun; Lee, Kyeongbong; Lee, GyuChang

2017-10-01

Although the Kinect gaming system (Microsoft Corp, Redmond, WA) has been shown to be of therapeutic benefit in rehabilitation, the applicability of Kinect-based virtual reality (VR) training to improve motor function following a stroke has not been investigated. This study aimed to investigate the effects of VR training, using the Xbox Kinect-based game system, on the motor recovery of patients with chronic hemiplegic stroke. This was a randomized controlled trial. Twenty patients with hemiplegic stroke were randomly assigned to either the intervention group or the control group. Participants in the intervention group (n = 10) received 30 minutes of conventional physical therapy plus 30 minutes of VR training using Xbox Kinect-based games, and those in the control group (n = 10) received 30 minutes of conventional physical therapy only. All interventions consisted of daily sessions for a 6-week period. All measurements using Fugl-Meyer Assessment (FMA-LE), the Berg Balance Scale (BBS), the Timed Up and Go test (TUG), and the 10-meter Walk Test (10mWT) were performed at baseline and at the end of the 6 weeks. The scores on the FMA-LE, BBS, TUG, and 10mWT improved significantly from baseline to post intervention in both the intervention and the control groups after training. The pre-to-post difference scores on BBS, TUG, and 10mWT for the intervention group were significantly more improved than those for the control group (P <.05). Evidence from the present study supports the use of additional VR training with the Xbox Kinect gaming system as an effective therapeutic approach for improving motor function during stroke rehabilitation. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Acute effects of low-level laser therapy irradiation on blood lactate and muscle fatigue perception in hospitalized patients with heart failure-a pilot study.

PubMed

Bublitz, Caroline; Renno, Ana Claudia Muniz; Ramos, Rodrigo Santin; Assis, Livia; Sellera, Carlos Alberto Cyrillo; Trimer, Renata; Borghi-Silva, Audrey; Arena, Ross; Guizilini, Solange

2016-08-01

The objective of the present study is to evaluate the acute effects of low-level laser therapy (LLLT) on functional capacity, perceived exertion, and blood lactate in hospitalized patients with heart failure (HF). Patients diagnosed with systolic HF (left ventricular ejection fraction <45 %) were randomized and allocated prospectively into two groups: placebo LLLT group (n = 10)-subjects who were submitted to placebo laser and active LLLT group (n = 10)-subjects who were submitted to active laser. The 6-min walk test (6MWT) was performed, and blood lactate was determined at rest (before LLLT application and 6MWT), immediately after the exercise test (time 0) and recovery (3, 6, and 30 min). A multi-diode LLLT cluster probe (DMC, São Carlos, Brazil) was used. Both groups increased 6MWT distance after active or placebo LLLT application compared to baseline values (p = 0.03 and p = 0.01, respectively); however, no difference was observed during intergroup comparison. The active LLLT group showed a significant reduction in the perceived exertion Borg (PEB) scale compared to the placebo LLLT group (p = 0.006). In addition, the group that received active LLLT showed no statistically significant difference for the blood lactate level through the times analyzed. The placebo LLLT group demonstrated a significant increase in blood lactate between the rest and recovery phase (p < 0.05). Acute effects of LLLT irradiation on skeletal musculature were not able to improve the functional capacity of hospitalized patients with HF, although it may favorably modulate blood lactate metabolism and reduce perceived muscle fatigue.

Prediction of Maximal Oxygen Uptake by Six-Minute Walk Test and Body Mass Index in Healthy Boys.

PubMed

Jalili, Majid; Nazem, Farzad; Sazvar, Akbar; Ranjbar, Kamal

2018-05-14

To develop an equation to predict maximal oxygen uptake (VO2max) based on the 6-minute walk test (6MWT) and body composition in healthy boys. Direct VO2max, 6-minute walk distance, and anthropometric characteristics were measured in 349 healthy boys (12.49 ± 2.72 years). Multiple regression analysis was used to generate VO2max prediction equations. Cross-validation of the VO2max prediction equations was assessed with predicted residual sum of squares statistics. Pearson correlation was used to assess the correlation between measured and predicted VO2max. Objectively measured VO2max had a significant correlation with demographic and 6MWT characteristics (R = 0.11-0.723, P < .01). Multiple regression analysis revealed the following VO2max prediction equation: VO2max (mL/kg/min) = 12.701 + (0.06 × 6-minute walk distance m ) - (0.732 × body mass index kg/m2 ) (R 2 = 0.79, standard error of the estimate [SEE] = 2.91 mL/kg/min, %SEE = 6.9%). There was strong correlation between measured and predicted VO2max (r = 0.875, P < .001). Cross-validation revealed minimal shrinkage (R 2 p = 0.78 and predicted residual sum of squares SEE = 2.99 mL/kg/min). This study provides a relatively accurate and convenient VO2max prediction equation based on the 6MWT and body mass index in healthy boys. This model can be used for evaluation of cardiorespiratory fitness of boys in different settings. Copyright © 2018 Elsevier Inc. All rights reserved.

The use of the multiwavelet transform for the estimation of surface wave group and phase velocities and their associated uncertainties

NASA Astrophysics Data System (ADS)

Poppeliers, C.; Preston, L. A.

2017-12-01

Measurements of seismic surface wave dispersion can be used to infer the structure of the Earth's subsurface. Typically, to identify group- and phase-velocity, a series of narrow-band filters are applied to surface wave seismograms. Frequency dependent arrival times of surface waves can then be identified from the resulting suite of narrow band seismograms. The frequency-dependent velocity estimates are then inverted for subsurface velocity structure. However, this technique has no method to estimate the uncertainty of the measured surface wave velocities, and subsequently there is no estimate of uncertainty on, for example, tomographic results. For the work here, we explore using the multiwavelet transform (MWT) as an alternate method to estimate surface wave speeds. The MWT decomposes a signal similarly to the conventional filter bank technique, but with two primary advantages: 1) the time-frequency localization is optimized in regard to the time-frequency tradeoff, and 2) we can use the MWT to estimate the uncertainty of the resulting surface wave group- and phase-velocities. The uncertainties of the surface wave speed measurements can then be propagated into tomographic inversions to provide uncertainties of resolved Earth structure. As proof-of-concept, we apply our technique to four seismic ambient noise correlograms that were collected from the University of Nevada Reno seismic network near the Nevada National Security Site. We invert the estimated group- and phase-velocities, as well the uncertainties, for 1-D Earth structure for each station pair. These preliminary results generally agree with 1-D velocities that are obtained from inverting dispersion curves estimated from a conventional Gaussian filter bank.

Barriers associated with reduced physical activity in COPD patients*

PubMed Central

Amorim, Priscila Batista; Stelmach, Rafael; Carvalho, Celso Ricardo Fernandes; Fernandes, Frederico Leon Arrabal; Carvalho-Pinto, Regina Maria; Cukier, Alberto

2014-01-01

OBJECTIVE: To evaluate the ability of COPD patients to perform activities of daily living (ADL); to identify barriers that prevent these individuals from performing ADL; and to correlate those barriers with dyspnea severity, six-minute walk test (6MWT), and an ADL limitation score. METHODS: In COPD patients and healthy, age-matched controls, the number of steps, the distance walked, and walking time were recorded with a triaxial accelerometer, for seven consecutive days. A questionnaire regarding perceived barriers and the London Chest Activity of Daily Living (LCADL) scale were used in order to identify the factors that prevent the performance of ADL. The severity of dyspnea was assessed with two scales, whereas submaximal exercise capacity was determined on the basis of the 6MWT. RESULTS: We evaluated 40 COPD patients and 40 controls. In comparison with the control values, the mean walk time was significantly shorter for COPD patients (68.5 ± 25.8 min/day vs. 105.2 ± 49.4 min/day; p < 0.001), as was the distance walked (3.9 ± 1.9 km/day vs. 6.4 ± 3.2 km/day; p < 0.001). The COPD patients also walked fewer steps/day. The most common self-reported barriers to performing ADL were lack of infrastructure, social influences, and lack of willpower. The 6MWT distance correlated with the results obtained with the accelerometer but not with the LCADL scale results. CONCLUSIONS: Patients with COPD are less active than are healthy adults of a comparable age. Physical inactivity and the barriers to performing ADL have immediate implications for clinical practice, calling for early intervention measures. PMID:25410838

Responsiveness of physical function outcomes following physiotherapy intervention for osteoarthritis of the knee: an outcome comparison study.

PubMed

French, Helen P; Fitzpatrick, Martina; FitzGerald, Oliver

2011-12-01

To compare the responsiveness of two self-report measures and three physical performance measures of function following physiotherapy for osteoarthritis of the knee. Single centre study in acute hospital setting. Patients referred for physiotherapy with osteoarthritis of the knee were recruited. The Western Ontario and McMaster Universities (WOMAC), Lequesne Algofunctional Index (LAI), timed-up-and-go test (TUGT), timed-stand test (TST) and six-minute walk test (6MWT) were administered at first and final physiotherapy visits. Wilcoxon Signed Rank tests were used to determine the effect of physiotherapy on each outcome. Responsiveness was calculated using effect size, standardised response mean and a median-based measure of responsiveness due to some outlying data. Thirty-nine patients with a mean age of 65.3 (standard deviation 6.9) years were investigated before and after a course of exercise-based physiotherapy. There was a significant improvement in all outcomes except the WOMAC scores. All measures demonstrated small effect sizes for all statistics (<0.50), except the 6MWT which was in the moderate range for one of the indices (standardised response mean 0.54). The LAI was more responsive than the WOMAC total score and the WOMAC physical function subscale for all responsiveness statistics, whilst the 6MWT was more responsive than the TST and the TUGT. The median-based effect size index produced the smallest effect sizes for all measures (0.1 to 0.43). These results can be used to guide decision making about which physical function outcome measures should be used to evaluate effectiveness of rehabilitation of people with osteoarthritis of the knee at group level in a clinical setting. Copyright © 2010 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

[Impact of a Senso-Motoric Intervention in COPD-Patients Participating in an Outpatient Pulmonary Rehabilitation Program: A Randomized Controlled Trial].

PubMed

Spielmanns, M; Müller, K; Schott, N; Winkler, A; Polanski, H; Nell, C; Boeselt, T; Koczulla, A R; Storre, J H; Windisch, W; Magnet, F S; Baum, K

2017-06-01

Objective Exercise training provides a cornerstone of pulmonary rehabilitation (PR) in COPD-patients. However, the components of the training are not yet fully investigated. We conducted a randomized controlled trial to investigate the effectiveness of a sensory-motoric training (SMT) in comparison to a conventional strength training (KT) according to the physical performance. Patients and Methods: 43 COPD patients were randomized and participated either in the intervention group (SMT = 30 minutes SMT per day) or in the control group (KT = 30 minutes KT per day). The SMT was performed as circuit training with five stations. The primary endpoint was the difference between T1 (start of the PR) and T2 (end of the PR) in 5-Times Sit-to-stand test (5-STST) in the intergroup comparison. Secondary endpoints were the intra- and intergroup comparisons of T1 and T2 in the 6-Minute Walk Test (6-MWT), COPD Assessment Test (CAT), St. George Respiratory Questionnaire (SGRQ), Hospital Anxiety- and Depression Scale (HADS) and in lung function. Results No significant differences were seen in the results of the 5-STST between the groups. Likewise, in the 6-MWT, SGRQ, CAT, HADS and lung function. The intragroup comparison between T1 and T2 showed significant differences in 5-STST, 6-MWT, SGRQ, CAT and HADS in both groups. The differences in lung function were not significantly, neither in the inter- nor in the intragroup comparison. Conclusion Similarly to a conventional strength training improvements in exercise capacity could be achieved with a SMT during PR in COPD patients. Further studies are necessary to define the role of the SMT in regards to postural control. © Georg Thieme Verlag KG Stuttgart · New York.

Improvement in Quality of Life and Hemodynamics in Chronic Thromboembolic Pulmonary Hypertension Treated With Balloon Pulmonary Angioplasty.

PubMed

Darocha, Szymon; Pietura, Radosław; Pietrasik, Arkadiusz; Norwa, Justyna; Dobosiewicz, Anna; Piłka, Michał; Florczyk, Michał; Biederman, Andrzej; Torbicki, Adam; Kurzyna, Marcin

2017-03-24

The effect of balloon pulmonary angioplasty (BPA) on improvement in functional and hemodynamic parameters in chronic thromboembolic pulmonary hypertension (CTEPH) is known, but the quality of life (QoL) of patients treated with BPA has never been studied before.Methods and Results:Twenty-five patients with inoperable or persistent CTEPH were enrolled in the study and filled out the 36-item Short Form (SF-36v2) questionnaire twice: prior to commencement of BPA treatment and after ≥3 BPA sessions. In addition WHO functional class, distance on the 6-min walk test (6MWT) and hemodynamic parameters such as right atrial pressure (RAP), mean pulmonary artery pressure (mPAP), cardiac index (CI) and pulmonary vascular resistance (PVR) were assessed. QoL improved significantly in all domains, except for physical pain. Improvement in RAP (10.5±3.4 vs. 6.2±2.2 mmHg; P<0.05), mPAP (51.7±10.6 vs. 35.0±9.1 mmHg; P<0.05), CI (2.2±0.5 vs. 2.5±0.4 L/min·m 2 ; P=0.04), PVR (10.4±3.9 vs. 5.5±2.2 Wood units; P<0.05), functional class (96% vs. 20% in WHO class III and IV, P<0.05) and improvement in 6MWT distance (323±135 vs. 410±109 m; P<0.05) was observed. The only significant correlation was between the mental component summary score of QoL after completion of treatment and percentage improvement in the 6MWT (-0.404, P<0.05). Alongside improvement in functional and hemodynamic parameters, BPA also provides significant improvement in QoL.

The self-perception of dyspnoea threshold during the 6-min walk test: a good alternative to estimate the ventilatory threshold in chronic obstructive pulmonary disease.

PubMed

Couillard, Annabelle; Tremey, Emilie; Prefaut, Christian; Varray, Alain; Heraud, Nelly

2016-12-01

To determine and/or adjust exercise training intensity for patients when the cardiopulmonary exercise test is not accessible, the determination of dyspnoea threshold (defined as the onset of self-perceived breathing discomfort) during the 6-min walk test (6MWT) could be a good alternative. The aim of this study was to evaluate the feasibility and reproducibility of self-perceived dyspnoea threshold and to determine whether a useful equation to estimate ventilatory threshold from self-perceived dyspnoea threshold could be derived. A total of 82 patients were included and performed two 6MWTs, during which they raised a hand to signal self-perceived dyspnoea threshold. The reproducibility in terms of heart rate (HR) was analysed. On a subsample of patients (n=27), a stepwise regression analysis was carried out to obtain a predictive equation of HR at ventilatory threshold measured during a cardiopulmonary exercise test estimated from HR at self-perceived dyspnoea threshold, age and forced expiratory volume in 1 s. Overall, 80% of patients could identify self-perceived dyspnoea threshold during the 6MWT. Self-perceived dyspnoea threshold was reproducibly expressed in HR (coefficient of variation=2.8%). A stepwise regression analysis enabled estimation of HR at ventilatory threshold from HR at self-perceived dyspnoea threshold, age and forced expiratory volume in 1 s (adjusted r=0.79, r=0.63, and relative standard deviation=9.8 bpm). This study shows that a majority of patients with chronic obstructive pulmonary disease can identify a self-perceived dyspnoea threshold during the 6MWT. This HR at the dyspnoea threshold is highly reproducible and enable estimation of the HR at the ventilatory threshold.

The Shock and Vibration Digest, Volume 14, Number 4

DTIC Science & Technology

1982-04-01

temperature, humidity, shock, and vibration -- can influence this capability; as a result an almost continuous program of research and development has...pro- ducing reliability tests. For some time there has been interest in the Army Test Methodology program for developing a vibration system capable...geology of the Livermore Valley is obtained. 82-768 Transient Stress Wave Propagation in HTGR Fuel Element Impacts I.T. Almajan and P.D. Smith

Coupling a Supercritical Carbon Dioxide Brayton Cycle to a Helium-Cooled Reactor.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Middleton, Bobby; Pasch, James Jay; Kruizenga, Alan Michael

2016-01-01

This report outlines the thermodynamics of a supercritical carbon dioxide (sCO 2) recompression closed Brayton cycle (RCBC) coupled to a Helium-cooled nuclear reactor. The baseline reactor design for the study is the AREVA High Temperature Gas-Cooled Reactor (HTGR). Using the AREVA HTGR nominal operating parameters, an initial thermodynamic study was performed using Sandia's deterministic RCBC analysis program. Utilizing the output of the RCBC thermodynamic analysis, preliminary values of reactor power and of Helium flow rate through the reactor were calculated in Sandia's HelCO 2 code. Some research regarding materials requirements was then conducted to determine aspects of corrosion related tomore » both Helium and to sCO 2 , as well as some mechanical considerations for pressures and temperatures that will be seen by the piping and other components. This analysis resulted in a list of materials-related research items that need to be conducted in the future. A short assessment of dry heat rejection advantages of sCO 2> Brayton cycles was also included. This assessment lists some items that should be investigated in the future to better understand how sCO 2 Brayton cycles and nuclear can maximally contribute to optimizing the water efficiency of carbon free power generation« less

Theory for the Emergence of Modularity in Complex Systems

NASA Astrophysics Data System (ADS)

Deem, Michael; Park, Jeong-Man

2013-03-01

Biological systems are modular, and this modularity evolves over time and in different environments. A number of observations have been made of increased modularity in biological systems under increased environmental pressure. We here develop a theory for the dynamics of modularity in these systems. We find a principle of least action for the evolved modularity at long times. In addition, we find a fluctuation dissipation relation for the rate of change of modularity at short times. We discuss a number of biological and social systems that can be understood with this framework. The modularity of the protein-protein interaction network increases when yeast are exposed to heat shock, and the modularity of the protein-protein networks in both yeast and E. coli appears to have increased over evolutionary time. Food webs in low-energy, stressful environments are more modular than those in plentiful environments, arid ecologies are more modular during droughts, and foraging of sea otters is more modular when food is limiting. The modularity of social networks changes over time: stock brokers instant messaging networks are more modular under stressful market conditions, criminal networks are more modular under increased police pressure, and world trade network modularity has decreased

Effect of bilateral lower limb strengthening exercise on balance and walking in hemiparetic patients after stroke: a randomized controlled trial.

PubMed

Jeon, Hye Joo; Hwang, Byong Yong

2018-02-01

[Purpose] To evaluate the effect of bilateral lower limb strengthening designed to improve balance and walking in stroke patients. [Subjects and Methods] Twenty hemiparetic stroke patients were divided into two groups: a unilateral therapy group (UTG) (n=10) and a bilateral therapy group (BTG) (n=10). The UTG completed strength training only in the paretic lower limb. The BTG completed strength training in the paretic and non-paretic lower limbs. Assessment tools included the functional reach test (FRT), the Berg balance scale (BBS), the timed up and go (TUG) test, and a 10-meter walk test (10MWT). [Results] In both groups, the lower limb strengthening exercise for balance and walking significantly improved the FRT, BBS, TUG, and 10MWT scores. Compared with UTG, the BTG attained significantly improved FRT and BBS scores. [Conclusion] Bilateral therapy using this lower limb strengthening exercise effectively promotes balance in hemiparetic stroke patients.

Quantifying prosthetic gait deviation using simple outcome measures

PubMed Central

Kark, Lauren; Odell, Ross; McIntosh, Andrew S; Simmons, Anne

2016-01-01

AIM: To develop a subset of simple outcome measures to quantify prosthetic gait deviation without needing three-dimensional gait analysis (3DGA). METHODS: Eight unilateral, transfemoral amputees and 12 unilateral, transtibial amputees were recruited. Twenty-eight able-bodied controls were recruited. All participants underwent 3DGA, the timed-up-and-go test and the six-minute walk test (6MWT). The lower-limb amputees also completed the Prosthesis Evaluation Questionnaire. Results from 3DGA were summarised using the gait deviation index (GDI), which was subsequently regressed, using stepwise regression, against the other measures. RESULTS: Step-length (SL), self-selected walking speed (SSWS) and the distance walked during the 6MWT (6MWD) were significantly correlated with GDI. The 6MWD was the strongest, single predictor of the GDI, followed by SL and SSWS. The predictive ability of the regression equations were improved following inclusion of self-report data related to mobility and prosthetic utility. CONCLUSION: This study offers a practicable alternative to quantifying kinematic deviation without the need to conduct complete 3DGA. PMID:27335814

Contributions of sex, testosterone, and androgen receptor CAG repeat number to virtual Morris water maze performance.

PubMed

Nowak, Nicole T; Diamond, Michael P; Land, Susan J; Moffat, Scott D

2014-03-01

The possibility that androgens contribute to the male advantage typically found on measures of spatial cognition has been investigated using a variety of approaches. To date, evidence to support the notion that androgens affect spatial cognition in healthy young adults is somewhat equivocal. The present study sought to clarify the association between testosterone (T) and spatial performance by extending measurements of androgenicity to include both measures of circulating T as well as an androgen receptor-specific genetic marker. The aims of this study were to assess the contributions of sex, T, and androgen receptor CAG repeat number (CAGr) on virtual Morris water task (vMWT) performance in a group of healthy young men and women. The hypothesis that men would outperform women on vMWT outcomes was supported. Results indicate that CAGr may interact with T to impact navigation performance and suggest that consideration of androgen receptor sensitivity is an important consideration in evaluating hormone-behavior relationships. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of bilateral lower limb strengthening exercise on balance and walking in hemiparetic patients after stroke: a randomized controlled trial

PubMed Central

Jeon, Hye Joo; Hwang, Byong Yong

2018-01-01

[Purpose] To evaluate the effect of bilateral lower limb strengthening designed to improve balance and walking in stroke patients. [Subjects and Methods] Twenty hemiparetic stroke patients were divided into two groups: a unilateral therapy group (UTG) (n=10) and a bilateral therapy group (BTG) (n=10). The UTG completed strength training only in the paretic lower limb. The BTG completed strength training in the paretic and non-paretic lower limbs. Assessment tools included the functional reach test (FRT), the Berg balance scale (BBS), the timed up and go (TUG) test, and a 10-meter walk test (10MWT). [Results] In both groups, the lower limb strengthening exercise for balance and walking significantly improved the FRT, BBS, TUG, and 10MWT scores. Compared with UTG, the BTG attained significantly improved FRT and BBS scores. [Conclusion] Bilateral therapy using this lower limb strengthening exercise effectively promotes balance in hemiparetic stroke patients. PMID:29545693

Reference equations for the six-minute walk distance in the healthy Chinese population aged 18–59 years

PubMed Central

Zou, He; Zhu, Xiuruo; Zhang, Jia; Wang, Yi; Wu, Xiaozhen; Liu, Fang; Xie, Xiaofeng

2017-01-01

Background The six-minute walk test (6MWT) is a safe, simple, inexpensive tool for evaluating the functional exercise capacity of patients with chronic respiratory disease. However, there is a lack of standard reference equations for the six-minute walk distance (6MWD) in the healthy Chinese population aged 18–59 years. Aims The purposes of the present study were as follows: 1) to measure the anthropometric data and walking distance of a sample of healthy Chinese Han people aged 18–59 years; 2) to construct reference equations for the 6MWD; 3) to compare the measured 6MWD with previously published equations. Method The anthropometric data, demographic information, lung function, and walking distance of Chinese adults aged 18–59 years were prospectively measured using a standardized protocol. We obtained verbal consent from all the subjects before the test, and the study design was approved by the ethics committee of Wenzhou People's Hospital. The 6MWT was performed twice, and the longer distance was used for further analysis. Results A total of 643 subjects (319 females and 324 males) completed the 6MWT, and average walking distance was 601.6±55.51 m. The walking distance was compared between females and males (578±49.85 m vs. 623±52.53 m; p < 0.0001) and between physically active subjects and sedentary subjects (609.3±56.17 m vs. 592±53.23 m; p < 0.0001). Pearson’s correlation indicated that the 6MWD was significantly correlated with various demographic and the 6MWT variables, such as age, height, weight, body mass index (BMI), heart rate after the test and the difference in the heart rate before and after the test. Stepwise multiple regression analysis showed that age and height were independent predictors associated with the 6MWD. The reference equations from white, Canadian and Chilean populations tended to overestimate the walking distance in our subjects, while Brazilian and Arabian equations tended to underestimate the walking distance. There was no significant difference in the walking distance between Korean reference equations and the results of the current study. Conclusion In summary, age and height were the most significant predictors of the 6MWD, and regression equations could explain approximately 34% and 28% of the distance variance in the female and male groups, respectively. PMID:28910353

HTGR fuels and core development program. Quarterly progress report for the period ending August 31, 1975

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1975-09-30

Studies of reactions between core materials and coolant impurities, basic fission product transport mechanisms, core graphite development and testing, the development and testing of recyclable fuel systems, and physics and fuel management studies are described. Materials studies include irradiation capsule tests of both fuel and graphite. Experimental procedures and results are discussed and, where appropriate, the data are presented in tables, graphs, and photographs. (auth)

Survey of Modular Military Vehicles: Benefits and Burdens

DTIC Science & Technology

2016-01-01

Survey of Modular Military Vehicles: BENEFITS and BURDENS Jean M. Dasch and David J. Gorsich Modularity in military vehicle design is generally...considered a positive attribute that promotes adaptability, resilience, and cost savings. The benefits and burdens of modularity are considered by...Engineering Center, vehicles were considered based on horizontal modularity , vertical modularity , and distributed modularity . Examples were given for each

PILOT SCALE PROCESS EVALUATION OF REBURNING FOR IN-FURNACE NOX REDUCTION

EPA Science Inventory

The report gives results of coal and natural gas reburning application tests to a pilot scale 3.0 MWt furnace to provide the scaling information required for commercial application of reburning to pulverized-coal-fired boilers. Initial parametric studies had been conducted in a 2...

The relative efficiency of modular and non-modular networks of different size

PubMed Central

Tosh, Colin R.; McNally, Luke

2015-01-01

Most biological networks are modular but previous work with small model networks has indicated that modularity does not necessarily lead to increased functional efficiency. Most biological networks are large, however, and here we examine the relative functional efficiency of modular and non-modular neural networks at a range of sizes. We conduct a detailed analysis of efficiency in networks of two size classes: ‘small’ and ‘large’, and a less detailed analysis across a range of network sizes. The former analysis reveals that while the modular network is less efficient than one of the two non-modular networks considered when networks are small, it is usually equally or more efficient than both non-modular networks when networks are large. The latter analysis shows that in networks of small to intermediate size, modular networks are much more efficient that non-modular networks of the same (low) connective density. If connective density must be kept low to reduce energy needs for example, this could promote modularity. We have shown how relative functionality/performance scales with network size, but the precise nature of evolutionary relationship between network size and prevalence of modularity will depend on the costs of connectivity. PMID:25631996

Adaptive multi-resolution Modularity for detecting communities in networks

NASA Astrophysics Data System (ADS)

Chen, Shi; Wang, Zhi-Zhong; Bao, Mei-Hua; Tang, Liang; Zhou, Ji; Xiang, Ju; Li, Jian-Ming; Yi, Chen-He

2018-02-01

Community structure is a common topological property of complex networks, which attracted much attention from various fields. Optimizing quality functions for community structures is a kind of popular strategy for community detection, such as Modularity optimization. Here, we introduce a general definition of Modularity, by which several classical (multi-resolution) Modularity can be derived, and then propose a kind of adaptive (multi-resolution) Modularity that can combine the advantages of different Modularity. By applying the Modularity to various synthetic and real-world networks, we study the behaviors of the methods, showing the validity and advantages of the multi-resolution Modularity in community detection. The adaptive Modularity, as a kind of multi-resolution method, can naturally solve the first-type limit of Modularity and detect communities at different scales; it can quicken the disconnecting of communities and delay the breakup of communities in heterogeneous networks; and thus it is expected to generate the stable community structures in networks more effectively and have stronger tolerance against the second-type limit of Modularity.

Product modular design incorporating preventive maintenance issues

NASA Astrophysics Data System (ADS)

Gao, Yicong; Feng, Yixiong; Tan, Jianrong

2016-03-01

Traditional modular design methods lead to product maintenance problems, because the module form of a system is created according to either the function requirements or the manufacturing considerations. For solving these problems, a new modular design method is proposed with the considerations of not only the traditional function related attributes, but also the maintenance related ones. First, modularity parameters and modularity scenarios for product modularity are defined. Then the reliability and economic assessment models of product modularity strategies are formulated with the introduction of the effective working age of modules. A mathematical model used to evaluate the difference among the modules of the product so that the optimal module of the product can be established. After that, a multi-objective optimization problem based on metrics for preventive maintenance interval different degrees and preventive maintenance economics is formulated for modular optimization. Multi-objective GA is utilized to rapidly approximate the Pareto set of optimal modularity strategy trade-offs between preventive maintenance cost and preventive maintenance interval difference degree. Finally, a coordinate CNC boring machine is adopted to depict the process of product modularity. In addition, two factorial design experiments based on the modularity parameters are constructed and analyzed. These experiments investigate the impacts of these parameters on the optimal modularity strategies and the structure of module. The research proposes a new modular design method, which may help to improve the maintainability of product in modular design.

Detection and Monitoring of Airborne Nuclear Waste Materials. Annual Report to Department of Energy.

DTIC Science & Technology

1979-12-04

an active core , its detection by counting techniques is often slow and impractical. For these reasons NRL under contract with DoE undertook develop ...Protection and Measurements, Tritium Measurement Techniques NCRP Report No. 47 (1976). 2. " Development of a Continuous Tritium Monitor for Fuel Reprocessing...Trans. Am. Nucl. Soc. 21, 91 (1975). 146. "Process Behavior of and Environmental Assessments of C Releases from an HTGR Fuel Reprocessing Facility" J. W

The Shock and Vibration Digest. Volume 13, Number 4

DTIC Science & Technology

1981-04-01

Brazil to find and develop their offshore oil resources. Much detailed planning and organization have gone into this program . Given as background in...summer program is a specially developed course of study which is based on two regular MIT subjects (one graduate level and one undergraduate level...Seal on an HTGR Core Subjected to Seianic Support Motions A. Chuang General Atomic Co., San Diego, CA, ASME Paper No. 80-C2/PVP-21 Key Words

Kinetics of Chronic Oxidation of NBG-17 Nuclear Graphite by Water Vapor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Contescu, Cristian I; Burchell, Timothy D; Mee, Robert

2015-05-01

This report presents the results of kinetic measurements during accelerated oxidation tests of NBG-17 nuclear graphite by low concentration of water vapor and hydrogen in ultra-high purity helium. The objective is to determine the parameters in the Langmuir-Hinshelwood (L-H) equation describing the oxidation kinetics of nuclear graphite in the helium coolant of high temperature gas-cooled reactors (HTGR). Although the helium coolant chemistry is strictly controlled during normal operating conditions, trace amounts of moisture (predictably < 0.2 ppm) cannot be avoided. Prolonged exposure of graphite components to water vapor at high temperature will cause very slow (chronic) oxidation over the lifetimemore » of graphite components. This behavior must be understood and predicted for the design and safe operation of gas-cooled nuclear reactors. The results reported here show that, in general, oxidation by water of graphite NBG-17 obeys the L-H mechanism, previously documented for other graphite grades. However, the characteristic kinetic parameters that best describe oxidation rates measured for graphite NBG-17 are different than those reported previously for grades H-451 (General Atomics, 1978) and PCEA (ORNL, 2013). In some specific conditions, certain deviations from the generally accepted L-H model were observed for graphite NBG-17. This graphite is manufactured in Germany by SGL Carbon Group and is a possible candidate for the fuel elements and reflector blocks of HTGR.« less

Development of modularity in the neural activity of childrenʼs brains

NASA Astrophysics Data System (ADS)

Chen, Man; Deem, Michael W.

2015-02-01

We study how modularity of the human brain changes as children develop into adults. Theory suggests that modularity can enhance the response function of a networked system subject to changing external stimuli. Thus, greater cognitive performance might be achieved for more modular neural activity, and modularity might likely increase as children develop. The value of modularity calculated from functional magnetic resonance imaging (fMRI) data is observed to increase during childhood development and peak in young adulthood. Head motion is deconvolved from the fMRI data, and it is shown that the dependence of modularity on age is independent of the magnitude of head motion. A model is presented to illustrate how modularity can provide greater cognitive performance at short times, i.e. task switching. A fitness function is extracted from the model. Quasispecies theory is used to predict how the average modularity evolves with age, illustrating the increase of modularity during development from children to adults that arises from selection for rapid cognitive function in young adults. Experiments exploring the effect of modularity on cognitive performance are suggested. Modularity may be a potential biomarker for injury, rehabilitation, or disease.

Lower-extremity function in cognitively healthy aging, mild cognitive impairment, and Alzheimer's disease.

PubMed

Eggermont, Laura H; Gavett, Brandon E; Volkers, Karin M; Blankevoort, Christiaan G; Scherder, Erik J; Jefferson, Angela L; Steinberg, Eric; Nair, Anil; Green, Robert C; Stern, Robert A

2010-04-01

To examine differences in lower-extremity function in cognitive healthy older persons, older persons with mild cognitive impairment (MCI), and older persons with Alzheimer's disease (AD). Descriptive study. University Alzheimer's disease clinical and research program. Older persons (N=66) were studied (mean age, 76.7y); 22 were cognitively normal, 22 were diagnosed with probable MCI, 22 were diagnosed with probable AD. Not applicable. Lower-extremity function was assessed by the four-meter walk test (4MWT), Timed Up & Go (TUG) test, and sit-to-stand (STS) test. Analysis of variance, adjusting for covariates, revealed that performance on the 4MWT was significantly lower in the MCI and AD groups as compared with controls. TUG test performance was worse in the AD group compared with controls. No significant group differences were found for STS performance. These results suggest an association between cognitive impairment and lower-limb function in older persons. Walking speed could be evaluated for its possible utility in screening older persons at risk for cognitive impairment and falls. Copyright 2010 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

THE 6-MINUTE WALK TEST AND OTHER CLINICAL ENDPOINTS IN DUCHENNE MUSCULAR DYSTROPHY: RELIABILITY, CONCURRENT VALIDITY, AND MINIMAL CLINICALLY IMPORTANT DIFFERENCES FROM A MULTICENTER STUDY

PubMed Central

McDonald, Craig M; Henricson, Erik K; Abresch, R Ted; Florence, Julaine; Eagle, Michelle; Gappmaier, Eduard; Glanzman, Allan M; Spiegel, Robert; Barth, Jay; Elfring, Gary; Reha, Allen; Peltz, Stuart W

2013-01-01

Introduction: An international clinical trial enrolled 174 ambulatory males ≥5 years old with nonsense mutation Duchenne muscular dystrophy (nmDMD). Pretreatment data provide insight into reliability, concurrent validity, and minimal clinically important differences (MCIDs) of the 6-minute walk test (6MWT) and other endpoints. Methods: Screening and baseline evaluations included the 6-minute walk distance (6MWD), timed function tests (TFTs), quantitative strength by myometry, the PedsQL, heart rate–determined energy expenditure index, and other exploratory endpoints. Results: The 6MWT proved feasible and reliable in a multicenter context. Concurrent validity with other endpoints was excellent. The MCID for 6MWD was 28.5 and 31.7 meters based on 2 statistical distribution methods. Conclusions: The ratio of MCID to baseline mean is lower for 6MWD than for other endpoints. The 6MWD is an optimal primary endpoint for Duchenne muscular dystrophy (DMD) clinical trials that are focused therapeutically on preservation of ambulation and slowing of disease progression. Muscle Nerve 48: 357–368, 2013 PMID:23674289

District heating systems in Oradea, Romania

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lund, J.W.

1997-08-01

Oradea is located on the Crisul Repede River, in the northwestern corner of Romania almost due west of Budapest, Hungary. The city has a population around half a million people and can trace its origins back to the Neolithic Age. It was an urban settlement beginning in the 13th century and has been an economic and cultural center for the region. It is a geothermal city with 12 wells drilled within the city limits, six in the nearby Felix Spa and five in the Bors geothermal area to the west, with one doublet set at Nufarul. Currently, there are amore » variety of geothermal uses in the area, including space and greenhouse heating, domestic hot water supply, process heat, balneology and swimming pools. Wellhead temperatures range from 70 to 105{degrees}C with artesian flows of from 5 to 25 L/s. The present installed capacity is 25 MWt and the heat supply is estimated at 60,000 MWh per year (216,000 GJ/yr). With pumping, the production would double and adding four more doublets, the installed capacity be increased to 65 MWt.« less

Impact of sleep deprivation and obstructive sleep apnea syndrome on daytime vigilance and driving performance: a laboratory perspective.

PubMed

Pizza, F; Contardi, S; Mondini, S; Cirignotta, F

2012-01-01

To study the impact of sleepiness, a well-established cause of car accidents, on driving ability, we designed a 30-min monotonous simulated driving task. Our simulated driving task encompasses both primary vehicle control (standard deviation of lane position, crash occurrence) and secondary tasks (type and reaction times to divided attention tasks). Driving simulator data were correlated to subjective (state/trait) and objective (MSLT/MWT) sleepiness measures in healthy subjects undergoing sleep deprivation (SD) and in obstructive sleep apnea (OSAS) patients. SD induced severe sleepiness during nighttime, when state sleepiness increased while primary vehicle control ability worsened. After SD, driving ability decreased and was inversely correlated to subjective and objective sleepiness at MSLT. OSAS patients driving ability was well correlated to objective sleepiness, with inverse correlation to sleep propensity at the MSLT and even more strict relation with the ability to maintain wakefulness at the MWT. Sleepiness worsens driving ability in healthy subjects after SD and in OSAS patients. Driving ability correlates with subjective and objective sleepiness measures, in particular to the ability to maintain wakefulness.

Assessment of physical fatigability and fatigue perception in myasthenia gravis.

PubMed

Jordan, Berit; Mehl, Theresa; Schweden, Tabea L K; Menge, Uwe; Zierz, Stephan

2017-05-01

Fatigue includes both performance fatigability and fatigue perception. In 32 stable patients with generalized myasthenia gravis (MG) and 17 controls, time-dependent physical performance was assessed by the arm movement test (AMT) and 6-minute walk test (6MWT). MG patients presented with low quantitative MG scores (mean 0.5, SD 0.5) and without pathologic decrement. Fatigability was based on calculation of linear trend (LT) reflecting dynamic performance within subsequent constant time intervals. Perception of physical fatigue was analyzed using fatigue questionnaires. MG patients showed a negative LT in both AMT and 6MWT, significantly differing from stable performance in controls. LT inversely correlated with elevation of acetylcholine receptor antibodies (r = -0.59, P < 0.005) but not with quantitative MG score and fatigue perception. LT allows quantification of fatigability as an objective measurement of decline in individual performance, even in patients without obvious neuromuscular deficits in routine testing. The missing correlation of experienced fatigue supports the multidimensional fatigue model. Muscle Nerve 55: 657-663, 2017. © 2016 Wiley Periodicals, Inc.

Void effect analysis of Pb-208 of fast reactors with modified CANDLE burn-up scheme

DOE Office of Scientific and Technical Information (OSTI.GOV)

Widiawati, Nina, E-mail: nina-widiawati28@yahoo.com; Su’ud, Zaki, E-mail: szaki@fi.itb.ac.id

Void effect analysis of Pb-208 as coolant of fast reactors with modified candle burn-up scheme has been conducted. Lead cooled fast reactor (LFR) is one of the fourth-generation reactor designs. The reactor is designed with a thermal power output of 500 MWt. Modified CANDLE burn-up scheme allows the reactor to have long life operation by supplying only natural uranium as fuel cycle input. This scheme introducing discrete region, the fuel is initially put in region 1, after one cycle of 10 years of burn up it is shifted to region 2 and region 1 is filled by fresh natural uraniummore » fuel. The reactor is designed for 100 years with 10 regions arranged axially. The results of neutronic calculation showed that the void coefficients ranged from −0.6695443 % at BOC to −0.5273626 % at EOC for 500 MWt reactor. The void coefficients of Pb-208 more negative than Pb-nat. The results showed that the reactors with Pb-208 coolant have better level of safety than Pb-nat.« less

Dynamics of modularity of neural activity in the brain during development

NASA Astrophysics Data System (ADS)

Deem, Michael; Chen, Man

2014-03-01

Theory suggests that more modular systems can have better response functions at short times. This theory suggests that greater cognitive performance may be achieved for more modular neural activity, and that modularity of neural activity may, therefore, likely increase with development in children. We study the relationship between age and modularity of brain neural activity in developing children. The value of modularity calculated from fMRI data is observed to increase during childhood development and peak in young adulthood. We interpret these results as evidence of selection for plasticity in the cognitive function of the human brain. We present a model to illustrate how modularity can provide greater cognitive performance at short times and enhance fast, low-level, automatic cognitive processes. Conversely, high-level, effortful, conscious cognitive processes may not benefit from modularity. We use quasispecies theory to predict how the average modularity evolves with age, given a fitness function extracted from the model. We suggest further experiments exploring the effect of modularity on cognitive performance and suggest that modularity may be a potential biomarker for injury, rehabilitation, or disease.

Efficacy of tolfenamic acid and meloxicam in the control of postoperative pain following ovariohysterectomy in the cat.

PubMed

Benito-de-la-Víbora, Javier; Lascelles, B Duncan X; García-Fernández, Paloma; Freire, Milagros; de Segura, Ignacio A Gómez

2008-11-01

The hypothesis was that Visual Analog Scale (VAS) scores would be lower, and mechanical wound thresholds (MWT) higher, in cats receiving tolfenamic acid compared to those receiving placebo in the postoperative period following elective ovariohysterectomy. Sixty-nine client-owned cats. A prospective, randomized, blinded and placebo-controlled study was performed in cats which underwent ovariohysterectomy following preoperative tolfenamic acid, meloxicam, or placebo. A second dose of the same analgesic was administered 24 hours postoperatively. Assessments were made 1-hour before induction and 1, 2, 4, 6, 22, and 25 hours postoperatively. Pain was assessed by a blinded observer using Numerical Rating (NRS) and VAS scales. The MWT were measured using a force-measuring device. Group comparison was performed by using one-way ANOVA and chi-squared test for qualitative and quantitative data, respectively, and a mixed model for repeated measurements (p < 0.05). Sixty-five cats were included in the study. There were no differences between groups at baseline. There was a treatment effect on the NRS scores at 6, 22 and 25 hours. The meloxicam group was less painful than controls at 6 and 22 hours; both treatment groups were less painful than controls at 25 hours. There were no differences between groups in VAS for pain or sedation. The number of animals receiving rescue analgesia did not differ between groups. There was a treatment effect on MWT; thresholds in both treatment groups were significantly higher than that observed in controls at all time points. Preoperative tolfenamic acid or meloxicam reduced wound sensitivity following ovariohysterectomy in the cat. Tolfenamic acid and meloxicam administered preoperatively provided a similar analgesic effect in the postoperative period lasting 24 hours. Mechanical thresholds may be a better way of evaluating postoperative analgesia provided by nonsteroidal anti-inflammatory drugs in cats.

Alfaxalone or ketamine-medetomidine in cats undergoing ovariohysterectomy: a comparison of intra-operative parameters and post-operative pain.

PubMed

Kalchofner Guerrero, Karin S; Reichler, Iris M; Schwarz, Andrea; Jud, Rahel S; Hässig, Michael; Bettschart-Wolfensberger, Regula

2014-11-01

To compare post-operative pain in cats after alfaxalone or ketamine- medetomidine anaesthesia for ovariohysterectomy (OHE) and physiologic parameters during and after surgery. Prospective 'blinded' randomized clinical study. Twenty-one healthy cats. Cats were assigned randomly into two groups: Group A, anaesthesia was induced and maintained with alfaxalone [5 mg kg(-1) intravenously (IV) followed by boli (2 mg kg(-1) IV); Group MK, induction with ketamine (5 mg kg(-1) IV) after medetomidine (30 μg kg(-1) intramuscularly (IM)], and maintenance with ketamine (2 mg kg(-1) IV). Meloxicam (0.2 mg kg(-1) IV) was administered after surgery. Basic physiological data were collected. At time T = -2, 0, 0.5, 1, 2, 4, 6, 8, 12, 16, 20, and 24 hours post-operatively pain was assessed by three methods, a composite pain scale (CPS; 0-24 points), a visual analogue scale (VAS 0-100 mm), and a mechanical wound threshold (MWT) device. Butorphanol (0.2 mg kg(-1) IM) was administered if CPS was scored ≥13. Data were analyzed using a general linear model, Kruskal-Wallis analyses, Bonferroni-Dunn test, unpaired t-test and Fisher's exact test as relevant. Significance was set at p < 0.05. VASs were significantly higher at 0.5, 1, 2, 4, and 20 hours in group A; MWT values were significantly higher at 8 and 12 hours in group MK. Post-operative MWT decreased significantly compared to baseline in both groups. There was no difference in CPS at any time point. Five cats required rescue analgesia (four in A; one in MK). Anaesthesia with ketamine-medetomidine was found to provide better post-surgical analgesia than alfaxalone in cats undergoing OHE; however, primary hyperalgesia developed in both groups. Alfaxalone is suitable for induction and maintenance of anaesthesia in cats undergoing OHE, but administration of additional sedative and analgesic drugs is highly recommended. © 2014 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.

Disability affects the 6-minute walking distance in obese subjects (BMI>40 kg/m(2)).

PubMed

Donini, Lorenzo Maria; Poggiogalle, Eleonora; Mosca, Veronica; Pinto, Alessandro; Brunani, Amelia; Capodaglio, Paolo

2013-01-01

In obese subjects, the relative reduction of the skeletal muscle strength, the reduced cardio-pulmonary capacity and tolerance to effort, the higher metabolic costs and, therefore, the increased inefficiency of gait together with the increased prevalence of co-morbid conditions might interfere with walking. Performance tests, such as the six-minute walking test (6MWT), can unveil the limitations in cardio-respiratory and motor functions underlying the obesity-related disability. Therefore the aims of the present study were: to explore the determinants of the 6-minute walking distance (6MWD) and to investigate the predictors of interruption of the walk test in obese subjects. Obese patients [body mass index (BMI)>40 kg/m(2)] were recruited from January 2009 to December 2011. Anthropometry, body composition, specific questionnaire for Obesity-related Disabilities (TSD-OC test), fitness status and 6MWT data were evaluated. The correlation between the 6MWD and the potential independent variables (anthropometric parameters, body composition, muscle strength, flexibility and disability) were analysed. The variables which were singularly correlated with the response variable were included in a multivariated regression model. Finally, the correlation between nutritional and functional parameters and test interruption was investigated. 354 subjects (87 males, mean age 48.5 ± 14 years, 267 females, mean age 49.8 ± 15 years) were enrolled in the study. Age, weight, height, BMI, fat mass and fat free mass indexes, handgrip strength and disability were significantly correlated with the 6MWD and considered in the multivariate analysis. The determination coefficient of the regression analysis ranged from 0.21 to 0.47 for the different models. Body weight, BMI, waist circumference, TSD-OC test score and flexibility were found to be predictors of the 6MWT interruption. The present study demonstrated the impact of disability in obese subjects, together with age, anthropometric data, body composition and strength, on the 6-minute walking distance.

Disability Affects the 6-Minute Walking Distance in Obese Subjects (BMI>40 kg/m2)

PubMed Central

Donini, Lorenzo Maria; Poggiogalle, Eleonora; Mosca, Veronica; Pinto, Alessandro; Brunani, Amelia; Capodaglio, Paolo

2013-01-01

Introduction In obese subjects, the relative reduction of the skeletal muscle strength, the reduced cardio-pulmonary capacity and tolerance to effort, the higher metabolic costs and, therefore, the increased inefficiency of gait together with the increased prevalence of co-morbid conditions might interfere with walking. Performance tests, such as the six-minute walking test (6MWT), can unveil the limitations in cardio-respiratory and motor functions underlying the obesity-related disability. Therefore the aims of the present study were: to explore the determinants of the 6-minute walking distance (6MWD) and to investigate the predictors of interruption of the walk test in obese subjects. Methods Obese patients [body mass index (BMI)>40 kg/m2] were recruited from January 2009 to December 2011. Anthropometry, body composition, specific questionnaire for Obesity-related Disabilities (TSD-OC test), fitness status and 6MWT data were evaluated. The correlation between the 6MWD and the potential independent variables (anthropometric parameters, body composition, muscle strength, flexibility and disability) were analysed. The variables which were singularly correlated with the response variable were included in a multivariated regression model. Finally, the correlation between nutritional and functional parameters and test interruption was investigated. Results 354 subjects (87 males, mean age 48.5±14 years, 267 females, mean age 49.8±15 years) were enrolled in the study. Age, weight, height, BMI, fat mass and fat free mass indexes, handgrip strength and disability were significantly correlated with the 6MWD and considered in the multivariate analysis. The determination coefficient of the regression analysis ranged from 0.21 to 0.47 for the different models. Body weight, BMI, waist circumference, TSD-OC test score and flexibility were found to be predictors of the 6MWT interruption. Discussion The present study demonstrated the impact of disability in obese subjects, together with age, anthropometric data, body composition and strength, on the 6-minute walking distance. PMID:24146756

Effect of a walking skill training program in patients who have undergone total hip arthroplasty: Followup one year after surgery.

PubMed

Heiberg, Kristi Elisabeth; Bruun-Olsen, Vigdis; Ekeland, Arne; Mengshoel, Anne Marit

2012-03-01

To investigate the effect of a 12-session walking skill training program of weight-bearing activities on physical functioning and self-efficacy initiated in patients 3 months after total hip arthroplasty (THA). Sixty-eight patients with THA, 35 women and 33 men, with a mean age of 66 years (95% confidence interval [95% CI] 64, 67 years), were randomized to a training group (n = 35) or a control group without physiotherapy (n = 33). Assessments were performed before the intervention at 3 months (pretest), at 5 months (posttest 1), and at 12 months (posttest 2) after surgery. The primary outcome was the 6-minute walk test (6MWT). The secondary outcomes were the stair climbing test (ST); figure-of-eight test; Index of Muscle Function (IMF); active hip range of motion (ROM) in flexion, extension, and abduction; Harris Hip Score (HHS); self-efficacy; and Hip Dysfunction and Osteoarthritis Outcome Score. The training group had larger improvements than the control group at posttest 1 on the 6MWT with an adjusted mean difference of 52 meters (95% CI 29, 74 meters; P < 0.001) and on the ST of -1 second (95% CI -2, 0 seconds; P = 0.01).There were also improvements on the figure-of-eight test (P = 0.02), IMF (P = 0.001), active hip ROM in extension (P = 0.02), HHS (P = 0.05), and self-efficacy (P = 0.04). The difference between the groups persisted at posttest 2 on the 6MWT of 52 meters (95% CI 24, 80 meters; P < 0.001) and on the ST of -1 second (95% CI -3, 0 seconds; P = 0.05). The walking skill training program was effective, especially in improving walking both immediately after the intervention and 1 year after THA surgery. Copyright © 2012 by the American College of Rheumatology.

Six-minute walk test predicts all-cause mortality and technique failure in ambulatory peritoneal dialysis patients.

PubMed

Shi, Yuanyuan; Zheng, Dongxia; Zhang, Lin; Yu, Zanzhe; Yan, Hao; Ni, Zhaohui; Qian, Jiaqi; Fang, Wei

2017-02-01

This study investigated the associated factors of 6-min walk test (6MWT) and its predictive value of outcome in patients undergoing peritoneal dialysis (PD). This is a single centre prospective observational cohort study. Stable ambulatory PD patients in our centre between 1 May 2010 and 30 April 2011 were enrolled in this study. All included subjects performed 6MWT, and 6-min walk distances (6MWDs) were recorded. Patients were divided into two groups according to 6MWD and prospectively followed up until death, cessation of PD or to the end of the study (30 September 2012). A total of 145 patients were enrolled, including 63 (43%) males. Multiple stepwise regression showed that age (β = -0.295, P = 0.001), diastolic blood pressure (DBP) (β = 0.292, P = 0.001), left ventricular ejection fraction (LVEF) (β = 0.198, P = 0.019) were independently associated with lower 6MWD. By the end of the study, six (8%) patients died in long 6MWD group while 15 (20%) died in the short 6MWD group, a significantly lower patient survival was observed in short 6MWD group (Log-rank = 4.983, P = 0.026). Patients with short 6MWD also showed inferior technique survival (Log-rank = 4.838, P = 0.028). There was no significant difference in peritonitis-free survival between the two groups (Log-rank = 0.801, P = 0.371). However, more patients in short 6MWD group had been transferred to hemodialysis due to peritonitis (25% vs 4.2%, P = 0.013). Age, diastolic blood pressure, LVEF are independent associated factors of 6MWD in patients undergoing PD. Having the advantages of easy applicability and safety, 6MWT may be proposed as an important predictor of outcome in ambulatory PD patients. © 2016 Asian Pacific Society of Nephrology.

Bacterial community changes in copper and PEX drinking water pipeline biofilms under extra disinfection and magnetic water treatment.

PubMed

Inkinen, J; Jayaprakash, B; Ahonen, M; Pitkänen, T; Mäkinen, R; Pursiainen, A; Santo Domingo, J W; Salonen, H; Elk, M; Keinänen-Toivola, M M

2018-02-01

To study the stability of biofilms and water quality in pilot scale drinking water copper and PEX pipes in changing conditions (extra disinfection, magnetic water treatment, MWT). Next-generation sequencing (NGS) of 16S ribosomal RNA genes (rDNA) to describe total bacterial community and ribosomal RNA (rRNA) to describe active bacterial members in addition to traditional microbiological methods were applied. Biofilms from control copper and PEX pipes shared same most abundant bacteria (Methylobacterium spp., Sphingomonas spp., Zymomonas spp.) and average species diversities (Shannon 3·8-4·2) in rDNA and rRNA libraries, whereas few of the taxa differed by their abundance such as lower total Mycobacterium spp. occurrence in copper (<0·02%) to PEX (<0·2%) pipes. Extra disinfection (total chlorine increase from c. 0·5 to 1 mg l -1 ) affected total and active population in biofilms seen as decrease in many bacterial species and diversity (Shannon 2·7, P < 0·01, rRNA) and increase in Sphingomonas spp. as compared to control samples. Furthermore, extra-disinfected copper and PEX samples formed separate clusters in unweighted non-metric multidimensional scaling plot (rRNA) similarly to MWT-treated biofilms of copper (but not PEX) pipes that instead showed higher species diversity (Shannon 4·8, P < 0·05 interaction). Minor chlorine dose addition increased selection pressure and many species were sensitive to chlorination. Pipe material seemed to affect mycobacteria occurrence, and bacterial communities with MWT in copper but not in PEX pipes. This study using rRNA showed that chlorination affects especially active fraction of bacterial communities. Copper and PEX differed by the occurrence of some bacterial members despite similar community profiles. © 2017 The Society for Applied Microbiology.

A randomized study of the effects of exercise training on patients with atrial fibrillation.

PubMed

Osbak, Philip Samuel; Mourier, Malene; Kjaer, Andreas; Henriksen, Jens Henrik; Kofoed, Klaus Fuglsang; Jensen, Gorm Boje

2011-12-01

Exercise training is beneficial in ischemic and congestive heart disease. However, the effect on atrial fibrillation (AF) is unknown. Forty-nine patients with permanent AF (age [mean ± SD], 70.2 ± 7.8 years; male-to-female ratio, 0.75; body mass index [mean ± SD], 29.7 ± 4.3 kg/m(2)) were randomized to 12-week aerobic exercise training or a control group. Exercise capacity, 6-minute walk test (6MWT), cardiac output, quality of life, and natriuretic peptides were measured. Cardiac output was measured at rest and during ergometer testing, and atrial natriuretic peptide and N-terminal pro-B-type natriuretic peptide were measured before and after the training period. Quality of life was evaluated using the Short-Form 36 and Minnesota Living With Heart Failure (MLHF-Q) questionnaires. Improved exercise capacity and 6MWT were observed in the active patients (P < .001), and at study end, there was a significant difference between the active patients and the controls (P = .002). Resting pulse decreased in the active patients (94.8 ± 22.4 to 86.3 ± 22.5 beats/min, P = .049) but remained unchanged in the controls. Cardiac output was unchanged from baseline to end-of-study period. The MLHF-Q score improved in the active group (21.1 ± 18.0 vs 15.4 ± 17.5, P = .03). Active patients showed progress in 3 of the 8 Short-Form 36 subscales: physical functioning (P = .02), general health perceptions (P = .001), and vitality (P = .02). Natriuretic peptides were unchanged. Twelve weeks of exercise training increased exercise capacity and 6MWT and decreased resting pulse rate significantly in patients with AF. Overall quality of life increased significantly as measured by the cardiology-related MLHF-Q. Cardiac output and natriuretic peptides were unchanged in both groups. Copyright © 2011 Mosby, Inc. All rights reserved.

Ankle voluntary movement enhancement following robotic-assisted locomotor training in spinal cord injury.

PubMed

Varoqui, Deborah; Niu, Xun; Mirbagheri, Mehdi M

2014-03-31

In incomplete spinal cord injury (iSCI), sensorimotor impairments result in severe limitations to ambulation. To improve walking capacity, physical therapies using robotic-assisted locomotor devices, such as the Lokomat, have been developed. Following locomotor training, an improvement in gait capabilities-characterized by increases in the over-ground walking speed and endurance-is generally observed in patients. To better understand the mechanisms underlying these improvements, we studied the effects of Lokomat training on impaired ankle voluntary movement, known to be an important limiting factor in gait for iSCI patients. Fifteen chronic iSCI subjects performed twelve 1-hour sessions of Lokomat training over the course of a month. The voluntary movement was qualified by measuring active range of motion, maximal velocity peak and trajectory smoothness for the spastic ankle during a movement from full plantar-flexion (PF) to full dorsi-flexion (DF) at the patient's maximum speed. Dorsi- and plantar-flexor muscle strength was quantified by isometric maximal voluntary contraction (MVC). Clinical assessments were also performed using the Timed Up and Go (TUG), the 10-meter walk (10MWT) and the 6-minute walk (6MWT) tests. All evaluations were performed both before and after the training and were compared to a control group of fifteen iSCI patients. After the Lokomat training, the active range of motion, the maximal velocity, and the movement smoothness were significantly improved in the voluntary movement. Patients also exhibited an improvement in the MVC for their ankle dorsi- and plantar-flexor muscles. In terms of functional activity, we observed an enhancement in the mobility (TUG) and the over-ground gait velocity (10MWT) with training. Correlation tests indicated a significant relationship between ankle voluntary movement performance and the walking clinical assessments. The improvements of the kinematic and kinetic parameters of the ankle voluntary movement, and their correlation with the functional assessments, support the therapeutic effect of robotic-assisted locomotor training on motor impairment in chronic iSCI.

The effect of dietary nitrate supplementation on the oxygen cost of cycling, walking performance and resting blood pressure in individuals with chronic obstructive pulmonary disease: A double blind placebo controlled, randomised control trial.

PubMed

Shepherd, Anthony I; Wilkerson, Daryl P; Dobson, Lee; Kelly, James; Winyard, Paul G; Jones, Andrew M; Benjamin, Nigel; Shore, Angela C; Gilchrist, Mark

2015-08-01

Chronic obstructive pulmonary disease (COPD) results in exercise intolerance. Dietary nitrate supplementation has been shown to lower blood pressure (BP), reduce the oxygen cost of exercise, and enhance exercise tolerance in healthy volunteers. This study assessed the effects of dietary nitrate on the oxygen cost of cycling, walking performance and BP in individuals with mild-moderate COPD. Thirteen patients with mild-moderate COPD were recruited. Participants consumed 70 ml of either nitrate-rich (6.77 mmol nitrate; beetroot juice) or nitrate-depleted beetroot juice (0.002 mmol nitrate; placebo) twice a day for 2.5 days, with the final supplement ~3 hours before testing. BP was measured before completing two bouts of moderate-intensity cycling, where pulmonary gas exchange was measured throughout. The six-minute walk test (6 MWT) was completed 30 minutes subsequent to the second cycling bout. Plasma nitrate concentration was significantly elevated following beetroot juice vs. placebo (placebo; 48 ± 86 vs. beetroot juice; 215 ± 84 µM, P = 0.002). No significant differences were observed between placebo vs. beetroot juice for oxygen cost of exercise (933 ± 323 vs. 939 ± 302 ml: min(-1); P = 0.88), distance covered in the 6 MWT (456 ± 86 vs. 449 ± 79 m; P = 0.37), systolic BP (123 ± 14 vs. 123 ± 14 mmHg; P = 0.91), or diastolic BP (77 ± 9 vs. 79 ± 9 mmHg; P = 0.27). Despite a large rise in plasma nitrate concentration, two days of nitrate supplementation did not reduce the oxygen cost of moderate intensity cycling, increase distance covered in the 6 MWT, or lower BP. Copyright © 2015 Elsevier Inc. All rights reserved.

[The evaluation of nutritional status of stable COPD patients and to investigate the effect of nutritional status on perception of dyspnea, exercise capacity, body composition, hospitalisation and life quality].

PubMed

Ayar Karakoç, Gamze; Ernam, Dilek; Aka Aktürk, Ülkü; Öztaş, Selahattin; Oğur, Erhan; Kabadayı, Feyyaz

2016-06-01

Malnutrition is a comorbidity oftenly seen in COPD patients who have progressive chronic inflammation and severity. In this prospective study, we aimed to determine the nutritional status of stable COPD patients and to investigate the impact of nutritional status on perception of dyspnoea, exercise capacity, body composition, hospitalisation and life quality. COPD patients were assessed using previous smoking story, physical examination and irreversible airway obstruction. This study was done with 50 COPD patients older than 65 years of age and 30 control subjects. Exclusion criteria were also the co-existance of malignancies, malabsorbtion, DM, neurological diseases, renal failure and unstable cardiac diseases known to influence the nutritional state. The obstruction degree was evaluated by spirometry, nutritional status was classified by the MNA questionnaire, perception of dyspnoea was assessed by the MMRC scale, exercise capacity was assessed by the 6MWT, life quality was assessed by the CAT scale. Body composition parameters FM, FFM and FMI were analyzed and hospitalisations during 6 months after discharge were recorded. The COPD patients were divided into three groups as without malnutrition (n= 25,%50), under risk of malnutrition (n= 19,%38) and malnourished (n= 6,%12). The COPD severity, MMRC dyspnoea score, CAT score and hospitalisations during 6 months following were higher among the malnourished patients. On the other hand, body mass index, 6MWT results, FM and FFM were lower in malnourished patients. A positive correlation between FFM and 6MWT and a negative correlation between FFM and hospitalisation were observed. MNA is a well-developed questionnaire which evaluates malnutrition in COPD patients. We determined that malnourished COPD patients have higher airway obstruction degree, perception of dyspnoea, CAT score and lower exercise capacity and FFM. FFM is an independent predictor of exercise capacity and rehospitalisation during 6 months.

Dark chocolate acutely improves walking autonomy in patients with peripheral artery disease.

PubMed

Loffredo, Lorenzo; Perri, Ludovica; Catasca, Elisa; Pignatelli, Pasquale; Brancorsini, Monica; Nocella, Cristina; De Falco, Elena; Bartimoccia, Simona; Frati, Giacomo; Carnevale, Roberto; Violi, Francesco

2014-07-02

NOX-2, the catalytic subunit of NADPH oxidase, has a key role in the formation of reactive oxidant species and is implicated in impairing flow-mediated dilation (FMD). Dark chocolate exerts artery dilatation via down-regulating NOX2-mediated oxidative stress. The aim of this study was to investigate whether dark chocolate improves walking autonomy in peripheral artery disease (PAD) patients via an oxidative stress-mediated mechanism. FMD, serum levels of isoprostanes, nitrite/nitrate (NOx) and sNOX2-dp, a marker of blood NOX2 activity, maximal walking distance (MWD) and maximal walking time (MWT) were studied in 20 PAD patients (14 males and 6 females, mean age: 69±9 years) randomly allocated to 40 g of dark chocolate (>85% cocoa) or 40 g of milk chocolate (≤35% cocoa) in a single blind, cross-over design. The above variables were assessed at baseline and 2 hours after chocolate ingestion. Dark chocolate intake significantly increased MWD (+11%; P<0.001), MWT (+15%; P<0.001), serum NOx (+57%; P<0.001) and decreased serum isoprostanes (-23%; P=0.01) and sNOX2-dp (-37%; P<0.001); no changes of the above variables were observed after milk chocolate intake. Serum epicatechin and its methylated metabolite significantly increased only after dark chocolate ingestion. Multiple linear regression analysis showed that Δ of MWD was independently associated with Δ of MWT (P<0.001) and Δ of NOx (P=0.018). In vitro study demonstrated that HUVEC incubated with a mixture of polyphenols significantly increased nitric oxide (P<0.001) and decreased E-selectin (P<0.001) and VCAM1 (P<0.001). In PAD patients dark but not milk chocolate acutely improves walking autonomy with a mechanism possibly related to an oxidative stress-mediated mechanism involving NOX2 regulation. http://www.clinicaltrials.gov. Unique identifier: NCT01947712. © 2014 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Dark Chocolate Acutely Improves Walking Autonomy in Patients With Peripheral Artery Disease

PubMed Central

Loffredo, Lorenzo; Perri, Ludovica; Catasca, Elisa; Pignatelli, Pasquale; Brancorsini, Monica; Nocella, Cristina; De Falco, Elena; Bartimoccia, Simona; Frati, Giacomo; Carnevale, Roberto; Violi, Francesco

2014-01-01

Background NOX‐2, the catalytic subunit of NADPH oxidase, has a key role in the formation of reactive oxidant species and is implicated in impairing flow‐mediated dilation (FMD). Dark chocolate exerts artery dilatation via down‐regulating NOX2‐mediated oxidative stress. The aim of this study was to investigate whether dark chocolate improves walking autonomy in peripheral artery disease (PAD) patients via an oxidative stress‐mediated mechanism. Methods and Results FMD, serum levels of isoprostanes, nitrite/nitrate (NOx) and sNOX2‐dp, a marker of blood NOX2 activity, maximal walking distance (MWD) and maximal walking time (MWT) were studied in 20 PAD patients (14 males and 6 females, mean age: 69±9 years) randomly allocated to 40 g of dark chocolate (>85% cocoa) or 40 g of milk chocolate (≤35% cocoa) in a single blind, cross‐over design. The above variables were assessed at baseline and 2 hours after chocolate ingestion. Dark chocolate intake significantly increased MWD (+11%; P<0.001), MWT (+15%; P<0.001), serum NOx (+57%; P<0.001) and decreased serum isoprostanes (−23%; P=0.01) and sNOX2‐dp (−37%; P<0.001); no changes of the above variables were observed after milk chocolate intake. Serum epicatechin and its methylated metabolite significantly increased only after dark chocolate ingestion. Multiple linear regression analysis showed that Δ of MWD was independently associated with Δ of MWT (P<0.001) and Δ of NOx (P=0.018). In vitro study demonstrated that HUVEC incubated with a mixture of polyphenols significantly increased nitric oxide (P<0.001) and decreased E‐selectin (P<0.001) and VCAM1 (P<0.001). Conclusion In PAD patients dark but not milk chocolate acutely improves walking autonomy with a mechanism possibly related to an oxidative stress‐mediated mechanism involving NOX2 regulation. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT01947712. PMID:24990275

Randomized Controlled Trial to Examine the Impact of Aquatic Exercise Training on Functional Capacity, Balance, and Perceptions of Fatigue in Female Patients With Multiple Sclerosis.

PubMed

Kargarfard, Mehdi; Shariat, Ardalan; Ingle, Lee; Cleland, Joshua A; Kargarfard, Mina

2018-02-01

To assess the effects of an 8-week aquatic exercise training program on functional capacity, balance, and perceptions of fatigue in women with multiple sclerosis (MS). Randomized controlled design. Referral center of an MS society. Women (N=32; mean age ± SD, 36.4±8.2y) with diagnosed relapsing-remitting MS. After undergoing baseline testing by a neurologist, participants were allocated to either an intervention (aquatic training program, n=17) or a control group (n=15). The intervention consisted of an 8-week aquatic training program (3 supervised training sessions per week; session duration, 45-60min; 50%-75% estimated maximum heart rate). Six-minute walk test (6-MWT), balance (Berg Balance Scale [BBS]), and perceptions of fatigue (Modified Fatigue Impact Scale; [MFIS]) at baseline and after the 8-week intervention. Differences over time between the experimental and control groups were assessed by a 2×2 (group by time) repeated-measures analysis of variance. Thirty-two women completed the 8-week aquatic training intervention (experimental group, n=17; control group, n=15). All outcome measures improved in the experimental group: 6-MWT performance (pretest mean ± SD, 451±58m; posttest mean ± SD, 503±57m; P<.001); BBS (pretest mean ± SD, 53.59±1.70; posttest mean ± SD, 55.18±1.18; P<.001), and MFIS (pretest mean ± SD, 43.1±14.6; posttest mean ± SD, 32.8±5.9; P<.01). A significant group-by-time interaction was evident between the experimental and control groups for 6-MWT (P<.001, partial eta 2 [η p 2 ]=.551), BBS (P<.001, η p 2 =.423), and MFIS (P<.001, η p 2 =.679). Aquatic exercise training improved functional capacity, balance, and perceptions of fatigue in women with MS. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

A comparison of muscle strength and endurance, exercise capacity, fatigue perception and quality of life in patients with chronic obstructive pulmonary disease and healthy subjects: a cross-sectional study.

PubMed

Calik-Kutukcu, Ebru; Savci, Sema; Saglam, Melda; Vardar-Yagli, Naciye; Inal-Ince, Deniz; Arikan, Hulya; Aribas, Zeynep; Ozer, Ozge; Bosnak-Guclu, Meral; Coplu, Lutfi

2014-01-27

Chronic obstructive pulmonary disease (COPD) has significant systemic effects that substantially impact quality of life and survival. The purpose of this study was to assess and compare peripheral muscle strength and endurance, exercise capacity, fatigue perception and quality of life between patients with COPD and healthy subjects. Twenty COPD patients (mean FEV1 49.3 ± 19.2%) and 20 healthy subjects were included in the study. Pulmonary function testing and six-minute walk test (6MWT) were performed. Peripheral muscle strength was measured with a hand-held dynamometer, peripheral muscle endurance was evaluated with sit-ups, squats and modified push-ups tests. Fatigue perception was assessed using the Fatigue Impact Scale (FIS) and Fatigue Severity Scale (FSS). General quality of life was determined with the Nottingham Health Profile (NHP), and cough-specific quality of life was evaluated with the Leicester Cough Questionnaire (LCQ). Pulmonary functions, strength of shoulder abductor and flexor muscles, numbers of sit-ups and squats, 6MWT distance and 6MWT% were significantly lower in COPD patients than in healthy subjects (p < 0.05). FIS psychosocial sub-dimension and total scores, NHP scores for all sub-dimensions except pain sub-dimension of the COPD group were significantly higher than those of healthy subjects (p < 0.05). The LCQ physical, psychological and social sub-dimensions and total scores were significantly lower in COPD patients than in healthy subjects (p < 0.05). Pulmonary functions, peripheral muscle strength and endurance, exercise capacity and quality of life were adversely affected in patients with COPD. There are greater effect of fatigue on psychosocial functioning and general daily life activities and effect of cough on the quality of life in patients with COPD. This study supports the idea that COPD patients must be evaluated in a comprehensive manner for planning pulmonary rehabilitation programs.

Impact of chronic kidney disease on quality of life, lung function, and functional capacity.

PubMed

Teixeira, Carolina Guimarães; Duarte, Maria do Carmo M B; Prado, Cecília Maciel; Albuquerque, Emídio Cavalcanti de; Andrade, Lívia B

2014-01-01

To evaluate the impact of the chronic kidney disease (CKD) on quality of life, from the children's and their parents' perspective, respiratory muscle strength, lung function, and functional capacity in children and adolescents. Cross-sectional study of children with CKD aged 8 to 17 years. Those incapable of taking the tests were excluded. After an interview, quality of life by Pediatric Quality of Life Inventory) (PedsQL(TM)), muscular strength, pulmonary function tests, and the 6-minute walking test (6MWT) were applied. Student's t-test, ANOVA (difference in means), and Pearson's coefficient of correlation were used. The level of significance was set at 5%. Of the 40 patients, the mean distance walked at the 6MWT was 396 meters, and the mean final score at the quality of life test as perceived by the children and parents was 50.9 and 51, respectively. From the children's perspective, the transplanted patients had a higher quality of life score when compared to those undergoing hemodialysis (p<0.001); those who practiced physical activity had better quality of life when compared to the sedentary children (p<0.001). From the children's and the parents' perspectives, the male gender had a higher quality of life score (p<0.05). There was a positive correlation between the distance walked at the 6MWT and age, height, final PedsQL(TM), forced vital capacity (FVC), and forced expiratory volume in the first second (FEV1), as well as a negative correlation between FEV1/FVC and the distance walked. A significant reduction in the quality of life and the functional capacity was observed in children with CKD, influenced by the type of treatment, gender, and sedentary life style. Copyright © 2014 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Detectable changes in physical performance measures in elderly African Americans.

PubMed

Mangione, Kathleen Kline; Craik, Rebecca L; McCormick, Alyson A; Blevins, Heather L; White, Meaghan B; Sullivan-Marx, Eileen M; Tomlinson, James D

2010-06-01

African American older adults have higher rates of self-reported disability and lower physical performance scores compared with white older adults. Measures of physical performance are used to predict future morbidity and to determine the effect of exercise. Characteristics of performance measures are not known for African American older adults. The purpose of this study was to estimate the standard error of measurement (SEM) and minimal detectable change (MDC) for the Short Physical Performance Battery (SPPB), Timed "Up & Go" Test (TUG) time, free gait speed, fast gait speed, and Six-Minute Walk Test (6MWT) distance in frail African American adults. This observational measurement study used a test-retest design. Individuals were tested 2 times over a 1-week period. Demographic data collected included height, weight, number of medications, assistive device use, and Mini-Mental Status Examination (MMSE) scores. Participants then completed the 5 physical performance tests. Fifty-two participants (mean age=78 years) completed the study. The average MMSE score was 25 points, and the average body mass index was 29.4 kg/m(2). On average, participants took 7 medications, and the majority used assistive devices. Intraclass correlation coefficients (ICC [2,1]) were greater than .90, except for the SPPB score (ICC=.81). The SEMs were 1.2 points for the SPPB, 1.7 seconds for the TUG, 0.08 m/s for free gait speed, 0.09 m/s for fast gait speed, and 28 m for 6MWT distance. The MDC values were 2.9 points for the SPPB, 4 seconds for the TUG, 0.19 m/s for free gait speed, 0.21 m/s for fast gait speed, and 65 m for 6MWT distance. The entire sample was from an urban area. The SEMs were similar to previously reported values and can be used when working with African American and white older adults. Estimates of MDC were calculated to assist in clinical interpretation.

Exoskeleton-assisted gait training to improve gait in individuals with spinal cord injury: a pilot randomized study.

PubMed

Chang, Shuo-Hsiu; Afzal, Taimoor; Berliner, Jeffrey; Francisco, Gerard E

2018-01-01

Robotic wearable exoskeletons have been utilized as a gait training device in persons with spinal cord injury. This pilot study investigated the feasibility of offering exoskeleton-assisted gait training (EGT) on gait in individuals with incomplete spinal cord injury (iSCI) in preparation for a phase III RCT. The objective was to assess treatment reliability and potential efficacy of EGT and conventional physical therapy (CPT). Forty-four individuals were screened, and 13 were eligible to participate in the study. Nine participants consented and were randomly assigned to receive either EGT or CPT with focus on gait. Subjects received EGT or CPT, five sessions a week (1 h/session daily) for 3 weeks. American Spinal Injury Association (ASIA) Lower Extremity Motor Score (LEMS), 10-Meter Walk Test (10MWT), 6-Minute Walk Test (6MWT), Timed Up and Go (TUG) test, and gait characteristics including stride and step length, cadence and stance, and swing phase durations were assessed at the pre- and immediate post- training. Mean difference estimates with 95% confidence intervals were used to analyze the differences. After training, improvement was observed in the 6MWT for the EGT group. The CPT group showed significant improvement in the TUG test. Both the EGT and the CPT groups showed significant increase in the right step length. EGT group also showed improvement in the stride length. EGT could be applied to individuals with iSCI to facilitate gait recovery. The subjects were able to tolerate the treatment; however, exoskeleton size range may be a limiting factor in recruiting larger cohort of patients. Future studies with larger sample size are needed to investigate the effectiveness and efficacy of exoskeleton-assisted gait training as single gait training and combined with other gait training strategies. Clinicaltrials.org, NCT03011099, retrospectively registered on January 3, 2017.

Circulating biomarkers of hypertrophy and fibrosis in patients with hypertrophic cardiomyopathy assessed by cardiac magnetic resonance.

PubMed

Gawor, Monika; Śpiewak, Mateusz; Kubik, Agata; Wróbel, Aleksandra; Lutyńska, Anna; Marczak, Magdalena; Grzybowski, Jacek

2018-05-23

Myocardial fibrosis in hypertrophic cardiomyopathy (HCM) is associated with worse clinical outcomes. The availability of circulating biomarkers of myocardial fibrosis and hypertrophy would be helpful in clinical practice. The aim of this study was to evaluate usefulness of various biomarkers of myocardial fibrosis and hypertrophy in HCM. Levels of biomarkers: soluble ST2 (sST2), galectin-3 (Gal-3), growth differentiation factor-15 (GDF-15), NT-proBNP and high-sensitivity cardiac troponin T (hs-cTnT) were measured in 60 patients with HCM. All patients underwent cardiac magnetic resonance imaging to calculate parameters of hypertrophy and fibrosis. We observed positive correlations among sST2 levels and left ventricular mass (LVM) (r = 0.32, p = 0.012), LV mass indexed for the body surface area (LVMI) (r = 0.27, p = 0.036) and maximal wall thickness (MWT) (r = 0.31, p = 0.015). No correlation was found between Gal-3 and GDF-15 levels and hypertrophy and fibrosis parameters. We observed positive correlations among hs-cTnT levels and LVM (r = 0.58, p < 0.0001), LVMI (r = 0.48, p = 0.0001), MWT (r = 0.31, p = 0.015) and late gadolinium enhancement (LGE) mass (r = 0.37, p = 0.003). There were positive correlations between NT-proBNP levels and LVM (r = 0.33, p = 0.01), LVMI (r = 0.41, p = 0.001), MWT (r = 0.42, p < 0.001) and LGE mass (r = 0.44, p < 0.001). Although no correlation between sST2 levels and myocardial fibrosis was found, sST2 may provide some additional information about hypertrophy extension. NT-proBNP and hs-cTnT are useful biomarkers in assessment of hypertrophy and fibrosis in HCM.

A comparison of muscle strength and endurance, exercise capacity, fatigue perception and quality of life in patients with chronic obstructive pulmonary disease and healthy subjects: a cross-sectional study

PubMed Central

2014-01-01

Background Chronic obstructive pulmonary disease (COPD) has significant systemic effects that substantially impact quality of life and survival. The purpose of this study was to assess and compare peripheral muscle strength and endurance, exercise capacity, fatigue perception and quality of life between patients with COPD and healthy subjects. Methods Twenty COPD patients (mean FEV1 49.3 ± 19.2%) and 20 healthy subjects were included in the study. Pulmonary function testing and six-minute walk test (6MWT) were performed. Peripheral muscle strength was measured with a hand-held dynamometer, peripheral muscle endurance was evaluated with sit-ups, squats and modified push-ups tests. Fatigue perception was assessed using the Fatigue Impact Scale (FIS) and Fatigue Severity Scale (FSS). General quality of life was determined with the Nottingham Health Profile (NHP), and cough-specific quality of life was evaluated with the Leicester Cough Questionnaire (LCQ). Results Pulmonary functions, strength of shoulder abductor and flexor muscles, numbers of sit-ups and squats, 6MWT distance and 6MWT% were significantly lower in COPD patients than in healthy subjects (p < 0.05). FIS psychosocial sub-dimension and total scores, NHP scores for all sub-dimensions except pain sub-dimension of the COPD group were significantly higher than those of healthy subjects (p < 0.05). The LCQ physical, psychological and social sub-dimensions and total scores were significantly lower in COPD patients than in healthy subjects (p < 0.05). Conclusions Pulmonary functions, peripheral muscle strength and endurance, exercise capacity and quality of life were adversely affected in patients with COPD. There are greater effect of fatigue on psychosocial functioning and general daily life activities and effect of cough on the quality of life in patients with COPD. This study supports the idea that COPD patients must be evaluated in a comprehensive manner for planning pulmonary rehabilitation programs. PMID:24468029

Decline in measured glomerular filtration rate is associated with a decrease in endurance, strength, balance and fine motor skills.

PubMed

Hellberg, Matthias; Höglund, Peter; Svensson, Philippa; Abdulahi, Huda; Clyne, Naomi

2017-07-01

Physical performance in chronic kidney disease affects morbidity and mortality. The aim was to find out which measures of physical performance are important in chronic kidney disease (CKD) and if there are associations with declining measured glomerular filtration rate (GFR). Endurance was assessed by 6 min walk test (6-MWT) and stair climbing, muscular endurance by 30 s sit to stand, heel rises and toe lifts, strength by quadriceps- and handgrip-strength, balance by functional reach and Berg's balance scale, and fine motor skills by Moberg's picking-up test. GFR was measured by Iohexol clearance. The study comprised 101 patients with CKD 3b-5 not started dialysis, 40 women and 61 men, with a mean age of 67 ± 13 (range: 22 - 87) years. All measures of physical performance were impaired. A decrease in GFR of 10 mL/min per 1.73 m 2 corresponded to a 35 metre shorter walking distance in the 6-MWT. Multivariable linear regression analysis showed significant relationships between decline in GFR and the 6-MWT (P = 0.04), isometric quadriceps strength left (P = 0.04), balance measured as functional reach (P = 0.02) and fine motor skills in the left hand as measured by Moberg's picking-up test (P = 0.01), respectively, after sex, age, comorbidity and the interaction between sex and age had been taken into account. Endurance, muscular endurance, strength, balance and fine motor skills were impaired in patients with CKD 3b-5. Walking capacity, isometric quadriceps strength, balance, and fine motor skills were associated with declining GFR. The left extremities were more susceptible to GFR, ageing and comorbidities and seem thus to be more sensitive. © 2016 Asian Pacific Society of Nephrology.

The 6-minute walk test, motor function measure and quantitative thigh muscle MRI in Becker muscular dystrophy: A cross-sectional study.

PubMed

Fischer, Dirk; Hafner, Patricia; Rubino, Daniela; Schmid, Maurice; Neuhaus, Cornelia; Jung, Hans; Bieri, Oliver; Haas, Tanja; Gloor, Monika; Fischmann, Arne; Bonati, Ulrike

2016-07-01

Becker muscular dystrophy (BMD) has an incidence of 1 in 16 000 male births. This cross-sectional study investigated the relation between validated functional scores and quantitative MRI (qMRI) of thigh muscles in 20 ambulatory BMD patients, aged 18.3-60 years (mean 31.2; SD 11.1). Clinical assessments included the motor function measure (MFM) and its subscales, as well as timed function tests such as the 6-minute walk test (6MWT) and the timed 10-m run/walk test. Quantitative MRI of the thigh muscles included the mean fat fraction (MFF) using a 2-point Dixon (2-PD) technique, and transverse relaxation time (T2) measurements. The mean MFM value was 80.4%, SD 9.44 and the D1 subscore 54.5%, SD 19.9. The median 6MWT was 195m, IQR 160-330.2. The median 10-m run/walk test was 7.4 seconds, IQR 6.1-9.3. The mean fat fraction of the thigh muscles was 55.6%, SD 17.4%, mean T2 relaxation times of all muscles: 69.9 ms, SD 14.4. The flexors had the highest MFF and T2 relaxation times, followed by the extensors and the adductors. MFF and global T2 relaxation times were highly negatively correlated with the MFM total, D1-subscore and 6MWT, and positively correlated with the 10 m run/walk test time (p < 0.01). Age was not correlated with MFF, global T2 relaxation time or clinical assessments. Both MFF and T2 measures in the thigh muscle were well correlated with clinical function in BMD and may serve as a surrogate outcome measure in clinical trials. Copyright © 2016 Elsevier B.V. All rights reserved.

A comparison of respiratory and peripheral muscle strength, functional exercise capacity, activities of daily living and physical fitness in patients with cystic fibrosis and healthy subjects.

PubMed

Arikan, Hulya; Yatar, İlker; Calik-Kutukcu, Ebru; Aribas, Zeynep; Saglam, Melda; Vardar-Yagli, Naciye; Savci, Sema; Inal-Ince, Deniz; Ozcelik, Ugur; Kiper, Nural

2015-01-01

There are limited reports that compare muscle strength, functional exercise capacity, activities of daily living (ADL) and parameters of physical fitness of cystic fibrosis (CF) patients with healthy peers in the literature. The purpose of this study was to assess and compare respiratory and peripheral muscle strength, functional exercise capacity, ADL and physical fitness in patients with CF and healthy subjects. Nineteen patients with CF (mean forced expiratory volume in one second-FEV1: 86.56±18.36%) and 20 healthy subjects were included in this study. Respiratory (maximal inspiratory pressure-MIP and maximal expiratory pressure-MEP) and peripheral muscle strength (quadriceps, shoulder abductors and hand grip strength) were evaluated. Functional exercise capacity was determined with 6min walk test (6MWT). ADL was assessed with Glittre ADL test and physical fitness was assessed with Munich fitness test (MFT). There were not any statistically significant difference in MIP, %MIP, MEP and %MEP values between two groups (p>0.05). %Peripheral muscle strength (% quadriceps and shoulder abductors strength), 6MWT distance and %6MWT distance were significantly lower in patients with CF than those of healthy subjects (p<0.05). Glittre ADL-test time was significantly longer in patients with CF than healthy subjects (p<0.05). According to Munich fitness test, the number of bouncing a ball, hanging score, distance of standing vertical jumping and standing vertical jumping score were significantly lower in patients with CF than those of healthy subjects (p<0.05). Peripheral muscle strength, functional exercise capacity, ADL performance and speed, coordination, endurance and power components of physical fitness are adversely affected in mild-severe patients with CF compared to healthy peers. Evaluations must be done in comprehensive manner in patients with CF with all stages. Copyright © 2015 Elsevier Ltd. All rights reserved.

Nutritional status, physical performance and disability in the elderly of the Peruvian Andes.

PubMed

Tramontano, Alessandra; Veronese, Nicola; Giantin, Valter; Manzato, Enzo; Rodriguez-Hurtado, Diana; Trevisan, Caterina; De Zaiacomo, Francesca; Sergi, Giuseppe

2016-12-01

Although nutritional status plays an important part in the physical performance and disability of older people, this relationship has been little studied in developing countries. A study on the effects of nutritional status on the physical performance and functional status of elderly people living in rural areas of the Peruvian Andes. The study concerned 222 people aged ≥65 years living in a rural area of the Peruvian Andes. The Mini-Nutritional Assessment (MNA) was used to classify participants as malnourished (MNA <= 17), at risk of malnutrition (MNA 18-23), or well-nourished (MNA>= 24). The short physical performance battery (SPPB) and six-minute walking test (6MWT) were used to measure participants' physical performance. Disabilities were investigated by assessing participants' self-reported difficulty in performing one or more basic activities of daily living (ADL), and instrumental activities of daily living (IADL). The prevalence of malnutrition was 9.4 %, and more than half of our samples were at risk of malnutrition. After adjusting for potential confounders, malnourished individuals performed significantly worse than the other MNA groups in the SPPB (p for trend=0.001), 6MWT and IADL (p for trend < 0.0001 for both outcomes), but not in the ADL (p for trend = 0.23). Taking the well-nourished for reference, and after adjusting for potential confounders, malnutrition was significantly associated with disability in IADL (OR 5.36, 95 % CI 1.02-56.94; p = 0.05), and poor performance in the 6MWT (OR 2.73, 95 % CI 1.06-12.08; p = 0.03) and SPPB (OR 4.94, 95 % CI 1.01-24.07; p = 0.04). Poor nutritional status was found significantly associated with poor physical performance and poor functional status in elderly Peruvian individuals.

Effects of a predefined mini-trampoline training programme on balance, mobility and activities of daily living after stroke: a randomized controlled pilot study.

PubMed

Miklitsch, Claudia; Krewer, Carmen; Freivogel, Susanna; Steube, Diethard

2013-10-01

To investigate the effects of a predefined mini-trampoline therapy programme for increasing postural control, mobility and the ability to perform activities of daily living after stroke. Randomized non-blinded controlled pilot study. Neurological rehabilitation hospital. First-time stroke; age 18-80 years; independent standing ability for a minimum of 2 minutes. Patients were randomized into two groups: the mini-trampoline group (n = 20) received 10 sessions of balance training using the mini-trampoline over three weeks. The patients of the control group (n =20) participated 10 times in a group balance training also over three weeks. Postural control (Berg Balance Scale, BBS), mobility and gait endurance (timed 'up and go' test, TUG; 6-minute walk test, 6MWT) and the ability to perform activities of daily living (Barthel Index, BI). Measurements were undertaken prior to and after the intervention period. Both groups were comparable before the study. The mini-trampoline group improved significantly more in the BBS (P = 0.003) compared to the control group. Mean or median differences of both groups showed improvements in the TUG 10.12 seconds/7.23 seconds, the 6MWT 135 m/75 m and the BI 20 points/13 points for the mini-trampoline and control group, respectively. These outcome measurements did not differ significantly between the two groups. A predefined mini-trampoline training programme resulted in significantly increased postural control in stroke patients compared to balance training in a group. Although not statistically significant, the mini-trampoline training group showed increased improvement in mobility and activities of daily living. These differences could have been statistically significant if we had investigated more patients (i.e. a total sample of 84 patients for the TUG, 98 patients for the 6MWT, and 186 patients for the BI).

Modular Courses in British Higher Education: A Critical Assessment

ERIC Educational Resources Information Center

Church, Clive

1975-01-01

The trends towards modular course structures is examined. British conceptions of modularization are compared with American interpretations of modular instruction, the former shown to be concerned almost exclusively with content, the latter attempting more radical changes in students' learning behavior. Rationales for British modular schemes are…

The Shock and Vibration Digest. Volume 17, Number 2

DTIC Science & Technology

1985-02-01

phenomena relative to A computer program has been developed to -.- buildings, bridges, dams, and other struc- simulate the motions of bodies subjected to...1982). (57) Ikushima, T., Honma, T., and Ishiz- uka, H., "Seismic Research on Block-Type (47) Kadle, D.S. and Chwang, A.T., "Hy- HTGR Core ," Nucl...T., "A Seismic Study of High Temperature Gas-Cooled Reactor Core - (48) Yang, C.Y., Chiarito, V., and Dressel, with Block-Type Fuel ; 2nd Rept: An Ana

Measuring the physical and economic impact of filarial lymphoedema in Chikwawa district, Malawi: a case-control study.

PubMed

Stanton, Michelle C; Yamauchi, Masato; Mkwanda, Square Z; Ndhlovu, Paul; Matipula, Dorothy Emmie; Mackenzie, Charles; Kelly-Hope, Louise A

2017-04-03

Lymphatic filariasis (LF) is one of the primary causes of lymphoedema in sub-Saharan Africa, and has a significant impact on the quality of life (QoL) of those affected. In this paper we assess the relative impact of lymphoedema on mobility and income in Chikwawa district, Malawi. A random sample of 31 people with lymphoedema and 31 matched controls completed a QoL questionnaire from which both an overall and a mobility-specific score were calculated. Two mobility tests were undertaken, namely the 10 m walking test [10MWT] and timed up and go [TUG] test, and a subset of 10 cases-control pairs wore GPS data loggers for 3 weeks to measure their mobility in a more natural setting. Retrospective economic data was collected from all 31 case-control pairs, and each participant undertaking the GPS activity recorded daily earnings and health expenditure throughout the observation period. Cases had a significantly poorer overall QoL (cases = 32.2, controls = 6.0, P < 0.01) and mobility-specific (cases = 43.1, controls = 7.4, P < 0.01) scores in comparison to controls. Cases were also significantly slower (P < 0.01) at completing the timed mobility tests, e.g. mean 10MWT speed of 0.83 m/s in comparison to 1.10 m/s for controls. An inconsistent relationship was observed between mobility-specific QoL scores and the timed test results for cases (10MWT correlation = -0.06, 95% CI = (-0.41, 0.30)), indicating that their perceived disability differed from their measured disability, whereas the results were consistent for controls (10MWT correlation = -0.61, 95% CI = (-0.79, -0.34)). GPS summaries indicated that cases generally walk shorter distances at slower speeds than control, covering a smaller geographical area (median area by kernel smoothing: cases = 1.25 km 2 , controls = 2.10 km 2 , P = 0.16). Cases reported earning less than half that earned by controls per week (cases = $0.70, controls = $1.86, P = 0.064), with a smaller proportion of their earnings (16% vs 22%, P = 0.461) being spent on healthcare. Those affected by lymphoedema are at a clear disadvantage to their unaffected peers, experiencing a lower QoL as confirmed by both subjective and objective mobility measures, and lower income. This study also indicates that objective measures of mobility may be a useful supplement to self-assessed QoL questionnaires when assessing the future impact of lymphoedema management interventions.

Impact of cardiac resynchronisation therapy on physical ability and quality of life in patients with chronic heart failure.

PubMed

Kloch Badełek, Małgorzata; Klocek, Marek; Czarnecka, Danuta; Wojciechowska, Wiktoria; Wiliński, Jerzy; Kawecka Jaszcz, Kalina

2012-01-01

Chronic heart failure (CHF) is a serious public health problem associated with high rates of morbidity and mortality. Cardiac resynchronisation therapy (CRT) is a well established treatment for selected patients who do not respond to optimal drug treatment of CHF. To assess the impact of CRT on the physical ability and quality of life (QoL) of patients with CHF. The study group consisted of 60 patients (mean age: 66.3 ± 8.7 years, 57 males and three females) with CHF classified as NYHA class III or IV (despite optimal pharmacotherapy for more than three months), a left ventricular end-diastolic diameter ≥ 55 mm, ejection fraction (LVEF) ≤ 35%, and a QRS duration ≥ 130 ms. Just before CRT, and three months after the procedure, patients were assessed using echocardiography and the 6-minute walk test (6-MWT), while their QoL was assessed by the Psychological General Well-Being index (PGWB). Three months after CRT, a 10% increase in baseline values of the 6-MWT constituted a positive response - patients who improved in this manner were classified as responders. Changes of at least ± 10% from baseline values of the PGWB total index were considered as improvement or worsening in QoL. During the follow-up, three men died, and so 57 patients were included in the final analysis. At the end of the study, an increase in the walking distance during the 6-MWT (298.0 ± 107.4 m vs 373.1 ± 127.2 m; p 〈 0.001) was observed. After three months, 38 (66.7%) patients were classified as responders while 19 (33.3%) subjects were classified as non-responders to CRT. Concurrently, after CRT we observed an improvement in QoL in 34 (59.6%) patients, while 23 (41.4%) patients showed no such effect. Patients who demonstrated an increased QoL at three months after CRT were characterised by lower baseline values of the total PGWB index as well as its dimensions (with the exception of the general health dimension). Improvement in QoL after CRT was observed only in the responders group (p 〈 0.01). The implementation of CRT leads to a reduction of heart failure related symptoms and an increase in physical ability in roughly two thirds of patients. Improvement in QoL after CRT pertains only to patients who demonstrate simultaneously an improvement in their 6-MWT. None of the other baseline clinical and echocardiographic parameters were useful in predicting better QoL and exercise capacity after CRT implementation.

Dissociation of modular total hip arthroplasty at the neck-stem interface without dislocation.

PubMed

Kouzelis, A; Georgiou, C S; Megas, P

2012-12-01

Modular femoral and acetabular components are now widely used, but only a few complications related to the modularity itself have been reported. We describe a case of dissociation of the modular total hip arthroplasty (THA) at the femoral neck-stem interface during walking. The possible causes of this dissociation are discussed. Successful treatment was provided with surgical revision and replacement of the modular neck components. Surgeons who use modular components in hip arthroplasties should be aware of possible early complications in which the modularity of the prostheses is the major factor of failure.

Quasispecies theory for evolution of modularity.

PubMed

Park, Jeong-Man; Niestemski, Liang Ren; Deem, Michael W

2015-01-01

Biological systems are modular, and this modularity evolves over time and in different environments. A number of observations have been made of increased modularity in biological systems under increased environmental pressure. We here develop a quasispecies theory for the dynamics of modularity in populations of these systems. We show how the steady-state fitness in a randomly changing environment can be computed. We derive a fluctuation dissipation relation for the rate of change of modularity and use it to derive a relationship between rate of environmental changes and rate of growth of modularity. We also find a principle of least action for the evolved modularity at steady state. Finally, we compare our predictions to simulations of protein evolution and find them to be consistent.

Self-organized modularization in evolutionary algorithms.

PubMed

Dauscher, Peter; Uthmann, Thomas

2005-01-01

The principle of modularization has proven to be extremely successful in the field of technical applications and particularly for Software Engineering purposes. The question to be answered within the present article is whether mechanisms can also be identified within the framework of Evolutionary Computation that cause a modularization of solutions. We will concentrate on processes, where modularization results only from the typical evolutionary operators, i.e. selection and variation by recombination and mutation (and not, e.g., from special modularization operators). This is what we call Self-Organized Modularization. Based on a combination of two formalizations by Radcliffe and Altenberg, some quantitative measures of modularity are introduced. Particularly, we distinguish Built-in Modularity as an inherent property of a genotype and Effective Modularity, which depends on the rest of the population. These measures can easily be applied to a wide range of present Evolutionary Computation models. It will be shown, both theoretically and by simulation, that under certain conditions, Effective Modularity (as defined within this paper) can be a selection factor. This causes Self-Organized Modularization to take place. The experimental observations emphasize the importance of Effective Modularity in comparison with Built-in Modularity. Although the experimental results have been obtained using a minimalist toy model, they can lead to a number of consequences for existing models as well as for future approaches. Furthermore, the results suggest a complex self-amplification of highly modular equivalence classes in the case of respected relations. Since the well-known Holland schemata are just the equivalence classes of respected relations in most Simple Genetic Algorithms, this observation emphasizes the role of schemata as Building Blocks (in comparison with arbitrary subsets of the search space).

[Modular enteral nutrition in pediatrics].

PubMed

Murillo Sanchís, S; Prenafeta Ferré, M T; Sempere Luque, M D

1991-01-01

Modular Enteral Nutrition may be a substitute for Parenteral Nutrition in children with different pathologies. Study of 4 children with different pathologies selected from a group of 40 admitted to the Maternal-Childrens Hospital "Valle de Hebrón" in Barcelona, who received modular enteral nutrition. They were monitored on a daily basis by the Dietician Service. Modular enteral nutrition consists of modules of proteins, peptides, lipids, glucids and mineral salts-vitamins. 1.--Craneo-encephalic traumatisms with loss of consciousness, Feeding with a combination of parenteral nutrition and modular enteral nutrition for 7 days. In view of the tolerance and good results of the modular enteral nutrition, the parenteral nutrition was suspended and modular enteral nutrition alone used up to a total of 43 days. 2.--55% burns with 36 days of hyperproteic modular enteral nutrition together with normal feeding. A more rapid recovery was achieved with an increase in total proteins and albumin. 3.--Persistent diarrhoea with 31 days of modular enteral nutrition, 5 days on parenteral nutrition alone and 8 days on combined parenteral nutrition and modular enteral nutrition. In view of the tolerance and good results of the modular enteral nutrition, the parenteral nutrition was suspended. 4.--Mucoviscidosis with a total of 19 days on modular enteral nutrition, 12 of which were exclusively on modular enteral nutrition and 7 as a night supplement to normal feeding. We administered proteic intakes of up to 20% of the total calorific intake and in concentrations of up to 1.2 calories/ml of the final preparation, always with a good tolerance. Modular enteral nutrition can and should be used as a substitute for parenteral nutrition in children with different pathologies, thus preventing the complications inherent in parenteral nutrition.

Convergent evolution of modularity in metabolic networks through different community structures.

PubMed

Zhou, Wanding; Nakhleh, Luay

2012-09-14

It has been reported that the modularity of metabolic networks of bacteria is closely related to the variability of their living habitats. However, given the dependency of the modularity score on the community structure, it remains unknown whether organisms achieve certain modularity via similar or different community structures. In this work, we studied the relationship between similarities in modularity scores and similarities in community structures of the metabolic networks of 1021 species. Both similarities are then compared against the genetic distances. We revisited the association between modularity and variability of the microbial living environments and extended the analysis to other aspects of their life style such as temperature and oxygen requirements. We also tested both topological and biological intuition of the community structures identified and investigated the extent of their conservation with respect to the taxonomy. We find that similar modularities are realized by different community structures. We find that such convergent evolution of modularity is closely associated with the number of (distinct) enzymes in the organism's metabolome, a consequence of different life styles of the species. We find that the order of modularity is the same as the order of the number of the enzymes under the classification based on the temperature preference but not on the oxygen requirement. Besides, inspection of modularity-based communities reveals that these communities are graph-theoretically meaningful yet not reflective of specific biological functions. From an evolutionary perspective, we find that the community structures are conserved only at the level of kingdoms. Our results call for more investigation into the interplay between evolution and modularity: how evolution shapes modularity, and how modularity affects evolution (mainly in terms of fitness and evolvability). Further, our results call for exploring new measures of modularity and network communities that better correspond to functional categorizations.

Implicit Contractive Mappings in Modular Metric and Fuzzy Metric Spaces

PubMed Central

Hussain, N.; Salimi, P.

2014-01-01

The notion of modular metric spaces being a natural generalization of classical modulars over linear spaces like Lebesgue, Orlicz, Musielak-Orlicz, Lorentz, Orlicz-Lorentz, and Calderon-Lozanovskii spaces was recently introduced. In this paper we investigate the existence of fixed points of generalized α-admissible modular contractive mappings in modular metric spaces. As applications, we derive some new fixed point theorems in partially ordered modular metric spaces, Suzuki type fixed point theorems in modular metric spaces and new fixed point theorems for integral contractions. In last section, we develop an important relation between fuzzy metric and modular metric and deduce certain new fixed point results in triangular fuzzy metric spaces. Moreover, some examples are provided here to illustrate the usability of the obtained results. PMID:25003157

Modular Power Standard for Space Explorations Missions

NASA Technical Reports Server (NTRS)

Oeftering, Richard C.; Gardner, Brent G.

2016-01-01

Future human space exploration will most likely be composed of assemblies of multiple modular spacecraft elements with interconnected electrical power systems. An electrical system composed of a standardized set modular building blocks provides significant development, integration, and operational cost advantages. The modular approach can also provide the flexibility to configure power systems to meet the mission needs. A primary goal of the Advanced Exploration Systems (AES) Modular Power System (AMPS) project is to establish a Modular Power Standard that is needed to realize these benefits. This paper is intended to give the space exploration community a "first look" at the evolving Modular Power Standard and invite their comments and technical contributions.

EFFECTS OF COMBUSTION PARAMETERS ON POLYCHLORINATED DIBENZODIOXIN AND DIBENZOFURAN HOMOLOGUE PROFILES FROM MUNICIPAL WASTE AND COAL CO-COMBUSTION

EPA Science Inventory

Variation in polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran (PCDD and PCDF) homologue profiles from a pilot scale (0.6 MWt, 2x106 Btu/hr), co-fired-fuel [densified refuse derived fuel (dRDF) and high-sulfur Illinois coal] combustion system was used to provide i...

76 FR 39134 - ZIONSOLUTIONS, LLC; Zion Nuclear Power Station, Units 1 and 2 Exemption From Recordkeeping...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-05

...; Zion Nuclear Power Station, Units 1 and 2 Exemption From Recordkeeping Requirements 1.0 Background Zion Nuclear Power Station (ZNPS or Zion), Unit 1, is a Westinghouse 3250 MWt Pressurized Water Reactor which... previously applicable to the nuclear power units and associated systems, structures, and components (SSC) are...

76 FR 72007 - ZionSolutions, LLC; Zion Nuclear Power Station, Units 1 and 2; Exemption From Certain Security...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-21

...; Zion Nuclear Power Station, Units 1 and 2; Exemption From Certain Security Requirements 1.0 Background Zion Nuclear Power Station (ZNPS or Zion), Unit 1, is a Westinghouse 3250 MWt Pressurized Water Reactor... activities in nuclear power reactors against radiological sabotage,'' paragraph (b)(1) states, ``The licensee...

Configurable double-sided modular jet impingement assemblies for electronics cooling

DOEpatents

Zhou, Feng; Dede, Ercan Mehmet

2018-05-22

A modular jet impingement assembly includes an inlet tube fluidly coupled to a fluid inlet, an outlet tube fluidly coupled to a fluid outlet, and a modular manifold having a first distribution recess extending into a first side of the modular manifold, a second distribution recess extending into a second side of the modular manifold, a plurality of inlet connection tubes positioned at an inlet end of the modular manifold, and a plurality of outlet connection tubes positioned at an outlet end of the modular manifold. A first manifold insert is removably positioned within the first distribution recess, a second manifold insert is removably positioned within the second distribution recess, and a first and second heat transfer plate each removably coupled to the modular manifold. The first and second heat transfer plates each comprise an impingement surface.

Convergent evolution of modularity in metabolic networks through different community structures

PubMed Central

2012-01-01

Background It has been reported that the modularity of metabolic networks of bacteria is closely related to the variability of their living habitats. However, given the dependency of the modularity score on the community structure, it remains unknown whether organisms achieve certain modularity via similar or different community structures. Results In this work, we studied the relationship between similarities in modularity scores and similarities in community structures of the metabolic networks of 1021 species. Both similarities are then compared against the genetic distances. We revisited the association between modularity and variability of the microbial living environments and extended the analysis to other aspects of their life style such as temperature and oxygen requirements. We also tested both topological and biological intuition of the community structures identified and investigated the extent of their conservation with respect to the taxomony. Conclusions We find that similar modularities are realized by different community structures. We find that such convergent evolution of modularity is closely associated with the number of (distinct) enzymes in the organism’s metabolome, a consequence of different life styles of the species. We find that the order of modularity is the same as the order of the number of the enzymes under the classification based on the temperature preference but not on the oxygen requirement. Besides, inspection of modularity-based communities reveals that these communities are graph-theoretically meaningful yet not reflective of specific biological functions. From an evolutionary perspective, we find that the community structures are conserved only at the level of kingdoms. Our results call for more investigation into the interplay between evolution and modularity: how evolution shapes modularity, and how modularity affects evolution (mainly in terms of fitness and evolvability). Further, our results call for exploring new measures of modularity and network communities that better correspond to functional categorizations. PMID:22974099

Modular jet impingement assemblies with passive and active flow control for electronics cooling

DOEpatents

Zhou, Feng; Dede, Ercan Mehmet; Joshi, Shailesh

2016-09-13

Power electronics modules having modular jet impingement assembly utilized to cool heat generating devices are disclosed. The modular jet impingement assemblies include a modular manifold having a distribution recess, one or more angled inlet connection tubes positioned at an inlet end of the modular manifold that fluidly couple the inlet tube to the distribution recess and one or more outlet connection tubes positioned at an outlet end of the modular manifold that fluidly coupling the outlet tube to the distribution recess. The modular jet impingement assemblies include a manifold insert removably positioned within the distribution recess and include one or more inlet branch channels each including an impinging slot and one or more outlet branch channels each including a collecting slot. Further a heat transfer plate coupled to the modular manifold, the heat transfer plate comprising an impingement surface including an array of fins that extend toward the manifold insert.

Modular cathode assemblies and methods of using the same for electrochemical reduction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wiedmeyer, Stanley G.; Barnes, Laurel A.; Williamson, Mark A.

Modular cathode assemblies are useable in electrolytic reduction systems and include a basket through which fluid electrolyte may pass and exchange charge with a material to be reduced in the basket. The basket can be divided into upper and lower sections to provide entry for the material. Example embodiment cathode assemblies may have any shape to permit modular placement at any position in reduction systems. Modular cathode assemblies include a cathode plate in the basket, to which unique and opposite electrical power may be supplied. Example embodiment modular cathode assemblies may have standardized electrical connectors. Modular cathode assemblies may bemore » supported by a top plate of an electrolytic reduction system. Electrolytic oxide reduction systems are operated by positioning modular cathode and anode assemblies at desired positions, placing a material in the basket, and charging the modular assemblies to reduce the metal oxide.« less

Modular cathode assemblies and methods of using the same for electrochemical reduction

DOEpatents

Wiedmeyer, Stanley G; Barnes, Laurel A; Williamson, Mark A; Willit, James L

2014-12-02

Modular cathode assemblies are useable in electrolytic reduction systems and include a basket through which fluid electrolyte may pass and exchange charge with a material to be reduced in the basket. The basket can be divided into upper and lower sections to provide entry for the material. Example embodiment cathode assemblies may have any shape to permit modular placement at any position in reduction systems. Modular cathode assemblies include a cathode plate in the basket, to which unique and opposite electrical power may be supplied. Example embodiment modular cathode assemblies may have standardized electrical connectors. Modular cathode assemblies may be supported by a top plate of an electrolytic reduction system. Electrolytic oxide reduction systems are operated by positioning modular cathode and anode assemblies at desired positions, placing a material in the basket, and charging the modular assemblies to reduce the metal oxide.

The Current Status of Modular Coordination. A Research Correlation Conference of Building Research Institute, Division of Engineering and Industrial Research (Fall 1959).

ERIC Educational Resources Information Center

National Academy of Sciences - National Research Council, Washington, DC.

Publication of conference presentations include--(1) a brief review of current modular standard development, (2) the statistical status of modular practice, (3) availability of modular products, and (4) educational programs on modular coordination. Included are--(1) explanatory diagrams, (2) text of an open panel discussion, and (3) a list of…

Status of Chronic Oxidation Studies of Graphite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Contescu, Cristian I.; Mee, Robert W.

Graphite will undergo extremely slow, but continuous oxidation by traces of moisture that will be present, albeit at very low levels, in the helium coolant of HTGR. This chronic oxidation may cause degradation of mechanical strength and thermal properties of graphite components if a porous oxidation layer penetrates deep enough in the bulk of graphite components during the lifetime of the reactor. The current research on graphite chronic oxidation is motivated by the acute need to understand the behavior of each graphite grade during prolonged exposure to high temperature chemical attack by moisture. The goal is to provide the elementsmore » needed to develop predictive models for long-time oxidation behavior of graphite components in the cooling helium of HTGR. The tasks derived from this goal are: (1) Oxidation rate measurements in order to determine and validate a comprehensive kinetic model suitable for prediction of intrinsic oxidation rates as a function of temperature and oxidant gas composition; (2) Characterization of effective diffusivity of water vapor in the graphite pore system in order to account for the in-pore transport of moisture; and (3) Development and validation of a predictive model for the penetration depth of the oxidized layer, in order to assess the risk of oxidation caused damage of particular graphite grades after prolonged exposure to the environment of helium coolant in HTGR. The most important and most time consuming of these tasks is the measurement of oxidation rates in accelerated oxidation tests (but still under kinetic control) and the development of a reliable kinetic model. This report summarizes the status of chronic oxidation studies on graphite, and then focuses on model development activities, progress of kinetic measurements, validation of results, and improvement of the kinetic models. Analysis of current and past results obtained with three grades of showed that the classical Langmuir-Hinshelwood model cannot reproduce all data collected so far. Starting from here we propose a modification of the LH model to include temperature activation of graphite surface as a Boltzmann activation function. The enhanced Boltzmann-Langmuir-Hinshelwood model (BLH) was tested successfully on three grades of graphite. The model is a robust, comprehensive mathematical function that allows better fitting of experimental results spanning a wide range of temperature and partial pressures of water vapor and hydrogen. However, the model did not fit satisfactorily the data extracted from the old report on graphite H-451 oxidation by water.« less

Modular Design in Treaty Verification Equipment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Macarthur, Duncan Whittemore; Benz, Jacob; Tolk, Keith

2015-01-27

It is widely believed that modular design is a good thing. However, there are often few explicit arguments, or even an agreed range of definitions, to back up this belief. In this paper, we examine the potential range of design modularity, the implications of various amounts of modularity, and the advantages and disadvantages of each level of modular construction. We conclude with a comparison of the advantages and disadvantages of each type, as well as discuss many caveats that should be observed to take advantage of the positive features of modularity and minimize the effects of the negative. The tradeoffsmore » described in this paper will be evaluated during the conceptual design to determine what amount of modularity should be included.« less

Analysis of Advanced Modular Power Systems (AMPS) for Deep Space Exploration

NASA Technical Reports Server (NTRS)

Oeftering, Richard; Soeder, James F.; Beach, Ray

2014-01-01

The Advanced Modular Power Systems (AMPS) project is developing a modular approach to spacecraft power systems for exploration beyond Earth orbit. AMPS is intended to meet the need of reducing the cost of design development, test and integration and also reducing the operational logistics cost of supporting exploration missions. AMPS seeks to establish modular power building blocks with standardized electrical, mechanical, thermal and data interfaces that can be applied across multiple exploration vehicles. The presentation discusses the results of a cost analysis that compares the cost of the modular approach against a traditional non-modular approach.

In Silico Investigation of a Surgical Interface for Remote Control of Modular Miniature Robots in Minimally Invasive Surgery

PubMed Central

Zygomalas, Apollon; Giokas, Konstantinos; Koutsouris, Dimitrios

2014-01-01

Aim. Modular mini-robots can be used in novel minimally invasive surgery techniques like natural orifice transluminal endoscopic surgery (NOTES) and laparoendoscopic single site (LESS) surgery. The control of these miniature assistants is complicated. The aim of this study is the in silico investigation of a remote controlling interface for modular miniature robots which can be used in minimally invasive surgery. Methods. The conceptual controlling system was developed, programmed, and simulated using professional robotics simulation software. Three different modes of control were programmed. The remote controlling surgical interface was virtually designed as a high scale representation of the respective modular mini-robot, therefore a modular controlling system itself. Results. With the proposed modular controlling system the user could easily identify the conformation of the modular mini-robot and adequately modify it as needed. The arrangement of each module was always known. The in silico investigation gave useful information regarding the controlling mode, the adequate speed of rearrangements, and the number of modules needed for efficient working tasks. Conclusions. The proposed conceptual model may promote the research and development of more sophisticated modular controlling systems. Modular surgical interfaces may improve the handling and the dexterity of modular miniature robots during minimally invasive procedures. PMID:25295187

In silico investigation of a surgical interface for remote control of modular miniature robots in minimally invasive surgery.

PubMed

Zygomalas, Apollon; Giokas, Konstantinos; Koutsouris, Dimitrios

2014-01-01

Aim. Modular mini-robots can be used in novel minimally invasive surgery techniques like natural orifice transluminal endoscopic surgery (NOTES) and laparoendoscopic single site (LESS) surgery. The control of these miniature assistants is complicated. The aim of this study is the in silico investigation of a remote controlling interface for modular miniature robots which can be used in minimally invasive surgery. Methods. The conceptual controlling system was developed, programmed, and simulated using professional robotics simulation software. Three different modes of control were programmed. The remote controlling surgical interface was virtually designed as a high scale representation of the respective modular mini-robot, therefore a modular controlling system itself. Results. With the proposed modular controlling system the user could easily identify the conformation of the modular mini-robot and adequately modify it as needed. The arrangement of each module was always known. The in silico investigation gave useful information regarding the controlling mode, the adequate speed of rearrangements, and the number of modules needed for efficient working tasks. Conclusions. The proposed conceptual model may promote the research and development of more sophisticated modular controlling systems. Modular surgical interfaces may improve the handling and the dexterity of modular miniature robots during minimally invasive procedures.

Design strategies to address the effect of hydrophobic epitope on stability and in vitro assembly of modular virus‐like particle

PubMed Central

Tekewe, Alemu; Connors, Natalie K.; Middelberg, Anton P. J.

2016-01-01

Abstract Virus‐like particles (VLPs) and capsomere subunits have shown promising potential as safe and effective vaccine candidates. They can serve as platforms for the display of foreign epitopes on their surfaces in a modular architecture. Depending on the physicochemical properties of the antigenic modules, modularization may affect the expression, solubility and stability of capsomeres, and VLP assembly. In this study, three module designs of a rotavirus hydrophobic peptide (RV10) were synthesized using synthetic biology. Among the three synthetic modules, modularization of the murine polyomavirus VP1 with a single copy of RV10 flanked by long linkers and charged residues resulted in the expression of stable modular capsomeres. Further employing the approach of module titration of RV10 modules on each capsomere via Escherichia coli co‐expression of unmodified VP1 and modular VP1‐RV10 successfully translated purified modular capomeres into modular VLPs when assembled in vitro. Our results demonstrate that tailoring the physicochemical properties of modules to enhance modular capsomeres stability is achievable through synthetic biology designs. Combined with module titration strategy to avoid steric hindrance to intercapsomere interactions, this allows bioprocessing of bacterially produced in vitro assembled modular VLPs. PMID:27222486

Design strategies to address the effect of hydrophobic epitope on stability and in vitro assembly of modular virus-like particle.

PubMed

Tekewe, Alemu; Connors, Natalie K; Middelberg, Anton P J; Lua, Linda H L

2016-08-01

Virus-like particles (VLPs) and capsomere subunits have shown promising potential as safe and effective vaccine candidates. They can serve as platforms for the display of foreign epitopes on their surfaces in a modular architecture. Depending on the physicochemical properties of the antigenic modules, modularization may affect the expression, solubility and stability of capsomeres, and VLP assembly. In this study, three module designs of a rotavirus hydrophobic peptide (RV10) were synthesized using synthetic biology. Among the three synthetic modules, modularization of the murine polyomavirus VP1 with a single copy of RV10 flanked by long linkers and charged residues resulted in the expression of stable modular capsomeres. Further employing the approach of module titration of RV10 modules on each capsomere via Escherichia coli co-expression of unmodified VP1 and modular VP1-RV10 successfully translated purified modular capomeres into modular VLPs when assembled in vitro. Our results demonstrate that tailoring the physicochemical properties of modules to enhance modular capsomeres stability is achievable through synthetic biology designs. Combined with module titration strategy to avoid steric hindrance to intercapsomere interactions, this allows bioprocessing of bacterially produced in vitro assembled modular VLPs. © 2016 The Protein Society.

EVALUATION OF INTERNALLY STAGED COAL BURNERS AND SORBENT JET AERODYNAMICS FOR COMBINED SO2/NOX CONTROL IN UTILITY BOILERS; VOLUME 2. TESTING IN A 100 MILLION BTU/HR EXPERIMENTAL FURNACE

EPA Science Inventory

The report givesresults of100 million Btu/hr (29 MWt) experimental furnace to explore methods for achieving effective S02 removal in a coalfired utility boiler using calcium-based sorbents, through appropriate selection of injection location and injector design/operating paramete...

The Moving Window Technique: A Window into Developmental Changes in Attention during Facial Emotion Recognition

ERIC Educational Resources Information Center

Birmingham, Elina; Meixner, Tamara; Iarocci, Grace; Kanan, Christopher; Smilek, Daniel; Tanaka, James W.

2013-01-01

The strategies children employ to selectively attend to different parts of the face may reflect important developmental changes in facial emotion recognition. Using the Moving Window Technique (MWT), children aged 5-12 years and adults ("N" = 129) explored faces with a mouse-controlled window in an emotion recognition task. An…

Locomotor Tests Predict Community Mobility in Children and Youth with Cerebral Palsy

ERIC Educational Resources Information Center

Ferland, Chantale; Moffet, Helene; Maltais, Desiree

2012-01-01

Ambulatory children and youth with cerebral palsy have limitations in locomotor capacities and in community mobility. The ability of three locomotor tests to predict community mobility in this population (N = 49, 27 boys, 6-16 years old) was examined. The tests were a level ground walking test, the 6-min-Walk-Test (6MWT), and two tests of advanced…

Gas core reactors for actinide transmutation and breeder applications

NASA Technical Reports Server (NTRS)

Clement, J. D.; Rust, J. H.

1978-01-01

This work consists of design power plant studies for four types of reactor systems: uranium plasma core breeder, uranium plasma core actinide transmuter, UF6 breeder and UF6 actinide transmuter. The plasma core systems can be coupled to MHD generators to obtain high efficiency electrical power generation. A 1074 MWt UF6 breeder reactor was designed with a breeding ratio of 1.002 to guard against diversion of fuel. Using molten salt technology and a superheated steam cycle, an efficiency of 39.2% was obtained for the plant and the U233 inventory in the core and heat exchangers was limited to 105 Kg. It was found that the UF6 reactor can produce high fluxes (10 to the 14th power n/sq cm-sec) necessary for efficient burnup of actinide. However, the buildup of fissile isotopes posed severe heat transfer problems. Therefore, the flux in the actinide region must be decreased with time. Consequently, only beginning-of-life conditions were considered for the power plant design. A 577 MWt UF6 actinide transmutation reactor power plant was designed to operate with 39.3% efficiency and 102 Kg of U233 in the core and heat exchanger for beginning-of-life conditions.

Use of trunk stabilization and locomotor training in an adult with cerebellar ataxia: a single system design.

PubMed

Freund, Jane E; Stetts, Deborah M

2010-10-01

The purpose of this study is to describe the effects of trunk stabilization training and locomotor training (LT) using body-weight support on a treadmill (BWST) and overground walking on balance, gait, self-reported function, and trunk muscle performance in an adult with severe ataxia secondary to brain injury. There are no studies on the effectiveness of these combined interventions in persons with ataxia. The subject was a 23-year-old male who had a traumatic brain injury 13 months prior. An A-B-A withdrawal single-system design was used. Outcome measures were Berg Balance Test (BBT), timed unsupported stance, Functional Ambulation Category (FAC), 10-meter walk test (10-MWT), Outpatient Physical Therapy Improvement in Movement Assessment Log (OPTIMAL), transverse abdominis (TrA) thickness, and isometric trunk endurance tests. Performance on the BBT, timed unsupported stance, FAC, 10-MWT, and OPTIMAL each improved after 10 weeks of intervention. In additions, TrA symmetry at rest improved as did right side-bridge endurance time. LT, using BWST and overground walking, and trunk stabilization training may be effective in improving balance, gait, function, and trunk performance in individuals with severe ataxia. Further research with additional subjects is indicated.

Is physiotherapy integrated virtual walking effective on pain, function, and kinesiophobia in patients with non-specific low-back pain? Randomised controlled trial.

PubMed

Yilmaz Yelvar, Gul Deniz; Çırak, Yasemin; Dalkılınç, Murat; Parlak Demir, Yasemin; Guner, Zeynep; Boydak, Ayşenur

2017-02-01

According to literature, virtual reality was found to reduce pain and kinesiophobia in patients with chronic pain. The purpose of the study was to investigate short-term effect of the virtual reality on pain, function, and kinesiophobia in patients with subacute and chronic non-specific low-back pain METHODS: This randomised controlled study in which 44 patients were randomly assigned to the traditional physiotherapy (control group, 22 subjects) or virtual walking integrated physiotherapy (experimental group, 22 subjects). Before and after treatment, Visual Analog Scale (VAS), TAMPA Kinesiophobia Scale (TKS), Oswestry Disability Index (ODI), Nottingham Health Profile (NHP), Timed-up and go Test (TUG), 6-Minute Walk Test (6MWT), and Single-Leg Balance Test were assessed. The interaction effect between group and time was assessed by using repeated-measures analysis of covariance. After treatment, both groups showed improvement in all parameters. However, VAS, TKS, TUG, and 6MWT scores showed significant differences in favor of the experimental group. Virtual walking integrated physiotherapy reduces pain and kinesiophobia, and improved function in patients with subacute and chronic non-specific low-back pain in short term.

A PC-based high temperature gas reactor simulator for Indonesian conceptual HTR reactor basic training

NASA Astrophysics Data System (ADS)

Syarip; Po, L. C. C.

2018-05-01

In planning for nuclear power plant construction in Indonesia, helium cooled high temperature reactor (HTR) is favorable for not relying upon water supply that might be interrupted by earthquake. In order to train its personnel, BATAN has cooperated with Micro-Simulation Technology of USA to develop a 200 MWt PC-based simulation model PCTRAN/HTR. It operates in Win10 environment with graphic user interface (GUI). Normal operation of startup, power maneuvering, shutdown and accidents including pipe breaks and complete loss of AC power have been conducted. A sample case of safety analysis simulation to demonstrate the inherent safety features of HTR was done for helium pipe break malfunction scenario. The analysis was done for the variation of primary coolant pipe break i.e. from 0,1% - 0,5 % and 1% - 10 % helium gas leakages, while the reactor was operated at the maximum constant power of 10 MWt. The result shows that the highest temperature of HTR fuel centerline and coolant were 1150 °C and 1296 °C respectively. With 10 kg/s of helium flow in the reactor core, the thermal power will back to the startup position after 1287 s of helium pipe break malfunction.

The Effects of Massage Therapy on Multiple Sclerosis Patients' Quality of Life and Leg Function

PubMed Central

2014-01-01

Background. Massage therapy is a noninvasive treatment that many individuals with multiple sclerosis (MS) use to supplement their conventional treatment. Objective. We hypothesize that massage therapy will improve the leg function and overall quality of life (QoL) of MS patients. Design. A two-period (rest, massage) crossover design was used. Twenty-four individuals with MS ranging from 3.0 to 7.0 on the Expanded Disability Status Scale (EDSS) received Swedish massage treatments for four weeks. Exercise capacity and leg function as well as QoL were assessed using the Six-Minute Walk Test (6MWT) and the Hamburg Quality of Life in Multiple Sclerosis (HAQUAMS) instrument, respectively. Assessments were measured before and after a massage period and a rest period where no massages were employed. Results. The results displayed no significant changes in 6MWT distances or HAQUAMS scores. However, the participants perceived improvement in overall health as expressed in written comments. Conclusions. Massage is a safe, noninvasive treatment that may assist MS patients in managing the stress of their symptoms. Future studies with larger sample size and cortisol measures are warranted. PMID:24949078

Comparisons in fluctuation of muscle strength and function in patients with immune-mediated neuropathy treated with intravenous versus subcutaneous immunoglobulin.

PubMed

Christiansen, Ingelise; Markvardsen, Lars H; Jakobsen, Johannes

2018-04-01

Variations in muscle strength and function have not been studied in patients with chronic inflammatory demyelinating polyneuropathy and multifocal motor neuropathy whose treatment regimen has been changed from intravenous to subcutaneous immunoglobulin (IVIg to SCIg). In a prospective, open-label study, patients were changed from monthly IVIg to weekly SCIg. The primary endpoint was variation in isokinetic muscle strength (cIKS). Secondary endpoints were variations in Medical Research Council (MRC) score, grip strength (GS), 9-hole-peg test (9-HPT), and 40-meter-walk test (40-MWT). The coefficient of variance of cIKS during the IVIg and SCIg treatment periods was unchanged (mean ± SD: 6.97 ± 4.83% vs. 5.50 ± 3.13%, P = 0.21). The variations in the 9-HPT and 40-MWT were significantly lower in the SCIg group (P = 0.01 and P = 0.005, respectively). When therapy was changed from IVIg to SCIg, fluctuation of muscle strength was unchanged, but performance fluctuations were diminished. Muscle Nerve 57: 610-614, 2018. © 2017 Wiley Periodicals, Inc.

TRAC analyses for CCTF and SCTF tests and UPTF design/operation. [Cylindrical Core Test Facility; Slab Core Test Facility; Upper Plenum Test Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spore, J.W.; Cappiello, M.W.; Dotson, P.J.

The analytical support in 1985 for Cylindrical Core Test Facility (CCTF), Slab Core Test Facility (SCTF), and Upper Plenum Test Facility (UPTF) tests involves the posttest analysis of 16 tests that have already been run in the CCTF and the SCTF and the pretest analysis of 3 tests to be performed in the UPTF. Posttest analysis is used to provide insight into the detailed thermal-hydraulic phenomena occurring during the refill and reflood tests performed in CCTF and SCTF. Pretest analysis is used to ensure that the test facility is operated in a manner consistent with the expected behavior of anmore » operating full-scale plant during an accident. To obtain expected behavior of a plant during an accident, two plant loss-of-coolant-accident (LOCA) calculations were performed: a 200% cold-leg-break LOCA calculation for a 2772 MW(t) Babcock and Wilcox plant and a 200% cold-leg-break LOCA calculation for a 3315 MW(t) Westinghouse plant. Detailed results are presented for several CCTF UPI tests and the Westinghouse plant analysis.« less

The effects of smartphone multitasking on gait and dynamic balance.

PubMed

Lee, Jeon Hyeong; Lee, Myoung Hee

2018-02-01

[Purpose] This study was performed to analyze the influence of smartphone multitasking on gait and dynamic balance. [Subjects and Methods] The subjects were 19 male and 20 female university students. There were 4 types of gait tasks: General Gait (walking without a task), Task Gait 1 (walking while writing a message), Task Gait 2 (walking while writing a message and listening to music), Task Gait 3 (walking while writing a message and having a conversation). To exclude the learning effect, the order of tasks was randomized. The Zebris FDM-T treadmill system (Zebris Medical GmbH, Germany) was used to measure left and right step length and width, and a 10 m walking test (10MWT) was conducted for gait velocity. In addition, a Timed Up and Go test (TUG) was used to measure dynamic balance. All the tasks were performed 3 times, and the mean of the measured values was analyzed. [Results] There were no statistically significant differences in step length and width. There were statistically significant differences in the 10MWT and TUG tests. [Conclusion] Using a smartphone while walking decreases a person's dynamic balance and walking ability. It is considered that accident rates are higher when using a smartphone.

Preliminary Design Study of Medium Sized Gas Cooled Fast Reactor with Natural Uranium as Fuel Cycle Input

NASA Astrophysics Data System (ADS)

Meriyanti, Su'ud, Zaki; Rijal, K.; Zuhair, Ferhat, A.; Sekimoto, H.

2010-06-01

In this study a fesibility design study of medium sized (1000 MWt) gas cooled fast reactors which can utilize natural uranium as fuel cycle input has been conducted. Gas Cooled Fast Reactor (GFR) is among six types of Generation IV Nuclear Power Plants. GFR with its hard neuron spectrum is superior for closed fuel cycle, and its ability to be operated in high temperature (850° C) makes various options of utilizations become possible. To obtain the capability of consuming natural uranium as fuel cycle input, modified CANDLE burn-up scheme[1-6] is adopted this GFR system by dividing the core into 10 parts of equal volume axially. Due to the limitation of thermal hydraulic aspects, the average power density of the proposed design is selected about 70 W/cc. As an optimization results, a design of 1000 MWt reactors which can be operated 10 years without refueling and fuel shuffling and just need natural uranium as fuel cycle input is discussed. The average discharge burn-up is about 280 GWd/ton HM. Enough margin for criticallity was obtained for this reactor.

Muscle MRI and functional outcome measures in Becker muscular dystrophy.

PubMed

Barp, Andrea; Bello, Luca; Caumo, Luca; Campadello, Paola; Semplicini, Claudio; Lazzarotto, Annalisa; Sorarù, Gianni; Calore, Chiara; Rampado, Alessandro; Motta, Raffaella; Stramare, Roberto; Pegoraro, Elena

2017-11-22

Becker muscular dystrophy (BMD) is a neuromuscular disorder allelic to Duchenne muscular dystrophy (DMD), caused by in-frame mutations in the dystrophin gene, and characterized by a clinical progression that is both milder and more heterogeneous than DMD. Muscle magnetic resonance imaging (MRI) has been proposed as biomarker of disease progression in dystrophinopathies. Correlation with clinically meaningful outcome measures such as North Star Ambulatory Assessment (NSAA) and 6 minute walk test (6MWT) is paramount for biomarker qualification. In this study, 51 molecularly confirmed BMD patients (aged 7-69 years) underwent muscle MRI and were evaluated with functional measures (NSAA and 6MWT) at the time of the MRI, and subsequently after one year. We confirmed a pattern of fatty substitution involving mainly the hip extensors and most thigh muscles. Severity of muscle fatty substitution was significantly correlated with specific DMD mutations: in particular, patients with an isolated deletion of exon 48, or deletions bordering exon 51, showed milder involvement. Fat infiltration scores correlated with baseline functional measures, and predicted changes after 1 year. We conclude that in BMD, skeletal muscle MRI not only strongly correlates with motor function, but also helps in predicting functional deterioration within a 12-month time frame.

Knee flexor strength and balance control impairment may explain declines during prolonged walking in women with mild multiple sclerosis.

PubMed

Ramari, Cintia; Moraes, Andréa G; Tauil, Carlos B; von Glehn, Felipe; Motl, Robert; de David, Ana C

2018-02-01

Physiological factors such as muscle weakness and balance could explain declines in walking distance by multiple sclerosis (MS) patients. The purpose of this study was to characterize levels and examine associations among decline in walking distance, balance and muscular strength in women with mild MS. Participants included 28 women with mild relapsing-remitting MS and 21 women without MS. We executed the 6-min walk test (6MWT) to verify declines in walking distance. Isokinetic knee flexion (KF) and extension (KE) muscle strength was measured using a dynamometer. Balance was quantified using a force platform, with eyes open and closed, on a rigid and foam surface. The MS patients presented declines in walking, lower KF muscle strength, and worse balance than controls. KF strength and balance correlated with walking in the MS group. The KF strength explained differences between groups in walking. The KF strength and balance presented as predictors of walking slowing down in the 6MWT, in mild MS. Women with mild MS have strength impairment of knee flexor muscles and balance control impairment that may explain walking related motor fatigability during prolonged walking. Copyright © 2018 Elsevier B.V. All rights reserved.

Study Neutronic of Small Pb-Bi Cooled Non-Refuelling Nuclear Power Plant Reactor (SPINNOR) with Hexagonal Geometry Calculation

NASA Astrophysics Data System (ADS)

Nur Krisna, Dwita; Su'ud, Zaki

2017-01-01

Nuclear reactor technology is growing rapidly, especially in developing Nuclear Power Plant (NPP). The utilization of nuclear energy in power generation systems has been progressing phase of the first generation to the fourth generation. This final project paper discusses the analysis neutronic one-cooled fast reactor type Pb-Bi, which is capable of operating up to 20 years without refueling. This reactor uses Thorium Uranium Nitride as fuel and operating on power range 100-500MWtNPPs. The method of calculation used a computer simulation program utilizing the SRAC. SPINNOR reactor is designed with the geometry of hexagonal shaped terrace that radially divided into three regions, namely the outermost regions with highest percentage of fuel, the middle regions with medium percentage of fuel, and most in the area with the lowest percentage. SPINNOR fast reactor operated for 20 years with variations in the percentage of Uranium-233 by 7%, 7.75%, and 8.5%. The neutronic calculation and analysis show that the design can be optimized in a fast reactor for thermal power output SPINNOR 300MWt with a fuel fraction 60% and variations of Uranium-233 enrichment of 7%-8.5%.

Short-burst interval treadmill training walking capacity and performance in cerebral palsy: a pilot study.

PubMed

Bjornson, Kristie F; Moreau, Noelle; Bodkin, Amy Winter

2018-04-16

To examine the effect of short-burst interval locomotor treadmill training (SBLTT) on walking capacity and performance in cerebral palsy (CP). Twelve children with spastic diplegic CP (average 8.6 years) across Gross Motor Function Classification System levels II (8) and III (4) were randomized to 20 SBLTT sessions over 4 or 10 weeks. SBLTT consisted of alternating 30 seconds of slow and fast walking for 30 minutes/session. Outcomes included the 10 m walk test, one-minute walk test (1MWT), and timed-up-and go (TUG) (capacity) and StepWatch (performance) collected at baseline, post, and 6 weeks post. Fast speed (+.11, p = .04; +.11 m/s, p = .006), 1MWT (+11.2; +11.7 m, p = .006) and TUG (-1.7; -1.9 seconds, p = .006) improved post SBLTT and 6 weeks, respectively. Walking performance increased: average strides/day (+948; +1712, p < .001) and percent time in high strides rates (+0.4, p = 0.07; +0.2, p = .008). Pilot study suggests SBLTT may improve short-term walking capacity and performance.

Westinghouse Small Modular Reactor nuclear steam supply system design

DOE Office of Scientific and Technical Information (OSTI.GOV)

Memmott, M. J.; Harkness, A. W.; Van Wyk, J.

2012-07-01

The Westinghouse Small Modular Reactor (SMR) is an 800 MWt (>225 MWe) integral pressurized water reactor (iPWR), in which all of the components typically associated with the nuclear steam supply system (NSSS) of a nuclear power plant are incorporated within a single reactor pressure vessel. This paper is the first in a series of four papers which describe the design and functionality of the Westinghouse SMR. Also described in this series are the key drivers influencing the design of the Westinghouse SMR and the unique passive safety features of the Westinghouse SMR. Several critical motivators contributed to the development andmore » integration of the Westinghouse SMR design. These design driving motivators dictated the final configuration of the Westinghouse SMR to varying degrees, depending on the specific features under consideration. These design drivers include safety, economics, AP1000{sup R} reactor expertise and experience, research and development requirements, functionality of systems and components, size of the systems and vessels, simplicity of design, and licensing requirements. The Westinghouse SMR NSSS consists of an integral reactor vessel within a compact containment vessel. The core is located in the bottom of the reactor vessel and is composed of 89 modified Westinghouse 17x17 Robust Fuel Assemblies (RFA). These modified fuel assemblies have an active core length of only 2.4 m (8 ft) long, and the entirety of the core is encompassed by a radial reflector. The Westinghouse SMR core operates on a 24 month fuel cycle. The reactor vessel is approximately 24.4 m (80 ft) long and 3.7 m (12 ft) in diameter in order to facilitate standard rail shipping to the site. The reactor vessel houses hot and cold leg channels to facilitate coolant flow, control rod drive mechanisms (CRDM), instrumentation and cabling, an intermediate flange to separate flow and instrumentation and facilitate simpler refueling, a pressurizer, a straight tube, recirculating steam generator, and eight reactor coolant pumps (RCP). The containment vessel is 27.1 m (89 ft) long and 9.8 m (32 ft) in diameter, and is designed to withstand pressures up to 1.7 MPa (250 psi). It is completely submerged in a pool of water serving as a heat sink and radiation shield. Housed within the containment are four combined core makeup tanks (CMT)/passive residual heat removal (PRHR) heat exchangers, two in-containment pools (ICP), two ICP tanks and four valves which function as the automatic depressurization system (ADS). The PRHR heat exchangers are thermally connected to two different ultimate heat sink (UHS) tanks which provide transient cooling capabilities. (authors)« less

Westinghouse Small Modular Reactor passive safety system response to postulated events

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, M. C.; Wright, R. F.

2012-07-01

The Westinghouse Small Modular Reactor (SMR) is an 800 MWt (>225 MWe) integral pressurized water reactor. This paper is part of a series of four describing the design and safety features of the Westinghouse SMR. This paper focuses in particular upon the passive safety features and the safety system response of the Westinghouse SMR. The Westinghouse SMR design incorporates many features to minimize the effects of, and in some cases eliminates the possibility of postulated accidents. The small size of the reactor and the low power density limits the potential consequences of an accident relative to a large plant. Themore » integral design eliminates large loop piping, which significantly reduces the flow area of postulated loss of coolant accidents (LOCAs). The Westinghouse SMR containment is a high-pressure, compact design that normally operates at a partial vacuum. This facilitates heat removal from the containment during LOCA events. The containment is submerged in water which also aides the heat removal and provides an additional radionuclide filter. The Westinghouse SMR safety system design is passive, is based largely on the passive safety systems used in the AP1000{sup R} reactor, and provides mitigation of all design basis accidents without the need for AC electrical power for a period of seven days. Frequent faults, such as reactivity insertion events and loss of power events, are protected by first shutting down the nuclear reaction by inserting control rods, then providing cold, borated water through a passive, buoyancy-driven flow. Decay heat removal is provided using a layered approach that includes the passive removal of heat by the steam drum and independent passive heat removal system that transfers heat from the primary system to the environment. Less frequent faults such as loss of coolant accidents are mitigated by passive injection of a large quantity of water that is readily available inside containment. An automatic depressurization system is used to reduce the reactor pressure in a controlled manner to facilitate the passive injection. Long-term decay heat removal is accomplished using the passive heat removal systems augmented by heat transfer through the containment vessel to the environment. The passive injection systems are designed so that the fuel remains covered and effectively cooled throughout the event. Like during the frequent faults, the passive systems provide effective cooling without the need for ac power for seven days following the accident. Connections are available to add additional water to indefinitely cool the plant. The response of the safety systems of the Westinghouse SMR to various initiating faults has been examined. Among them, two accidents; an extended station blackout event, and a LOCA event have been evaluated to demonstrate how the plant will remain safe in the unlikely event that either should occur. (authors)« less

Modular workcells: modern methods for laboratory automation.

PubMed

Felder, R A

1998-12-01

Laboratory automation is beginning to become an indispensable survival tool for laboratories facing difficult market competition. However, estimates suggest that only 8% of laboratories will be able to afford total laboratory automation systems. Therefore, automation vendors have developed alternative hardware configurations called 'modular automation', to fit the smaller laboratory. Modular automation consists of consolidated analyzers, integrated analyzers, modular workcells, and pre- and post-analytical automation. These terms will be defined in this paper. Using a modular automation model, the automated core laboratory will become a site where laboratory data is evaluated by trained professionals to provide diagnostic information to practising physicians. Modem software information management and process control tools will complement modular hardware. Proper standardization that will allow vendor-independent modular configurations will assure success of this revolutionary new technology.

The Modular need for the Division Signal Battalion

DTIC Science & Technology

2017-06-09

findings and analyzes them to expand on them. It is with these findings and subsequent analysis that the case studies shape the answer to the three...These case studies focus on the signal leadership development and how it occurred in the pre-modular force structure, during modularity, and the...the comparative case study research. The case studies focus on signal leader development in a pre-modular signal force, a modular signal force, and

Modular Fixturing System

NASA Technical Reports Server (NTRS)

Littell, Justin Anderson (Inventor); Street, Jon P. (Inventor)

2017-01-01

The modular fixturing system of the present invention is modular, reusable and capable of significant customization, both in terms of system radius and system height, allowing it to be arranged and rearranged in numerous unique configurations. The system includes multiple modular stanchions having stanchion shafts and stanchion feet that removably attach to apertures in a table. Angle brackets attached to the modular stanchions support shelves. These shelves in turn provide support to work pieces during fabrication processes such as welding.

A Modularized Counselor-Education Program.

ERIC Educational Resources Information Center

Miller, Thomas V.; Dimattia, Dominic J.

1978-01-01

Counselor-education programs may be enriched through the use of modularized learning experiences. This article notes several recent articles on competency-based counselor education, the concepts of simulation and modularization, and describes the process of developing a modularized master's program at the University of Bridgeport in Connecticut.…

On the classification of weakly integral modular categories

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bruillard, Paul; Galindo, César; Ng, Siu-Hung

In this paper we classify all modular categories of dimension 4m, where m is an odd square-free integer, and all rank 6 and rank 7 weakly integral modular categories. This completes the classification of weakly integral modular categories through rank 7. In particular, our results imply that all integral modular categories of rank at most 7 are pointed (that is, every simple object has dimension 1). All the non-integral (but weakly integral) modular categories of ranks 6 and 7 have dimension 4m, with m an odd square free integer, so their classification is an application of our main result. Themore » classification of rank 7 integral modular categories is facilitated by an analysis of the two group actions on modular categories: the Galois group of the field generated by the entries of the S-matrix and the group of invertible isomorphism classes of objects. We derive some valuable arithmetic consequences from these actions.« less

MFPG. The Role of Coatings in the Prevention of Mechanical Failures. Proceedings of the 23rd Meeting of the Mechanical Failures Prevention Group, Held at the National Bureau of Standards, Gaithersburg, Maryland on October 29-31, 1975

DTIC Science & Technology

1976-09-01

testing evaluation and production process development . This coated microspherical fuel particle has been successfully developed over a period of...this reliable concept began with attempts to blend ceramic (oxide or carbide) fuel powders into a graphite matrix in the early concepts of ROVER, HTGR ...lubricants. An ongoing program at the Naval Air Development Center is investigating how some parameters affect corro- sion between solid film

Briefing Book. Volume 1: The Evolution of the Nuclear Non-Proliferation Regime (Fourth Edition).

DTIC Science & Technology

1998-01-01

usually termed) nuclear reactors. The first of these is that they contain a core or mass of fissile material (the fuel ) which may weigh tens of tons... HTGR is cooled with helium gas and moderated with graphite. Highly enriched uranium is used as fuel (93 per cent U-235), though this may be mixed with...to convert U-238 in a blanket around the core into Pu-239 at a rate faster than its own consumption of fissile material. They thus produce more fuel

Heatpipe space power and propulsion systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Houts, M.G.; Poston, D.I.; Ranken, W.A.

1996-03-01

Safe, reliable, low-mass space power and propulsion systems could have numerous civilian and military applications. This paper discusses two fission-powered concepts: the Heatpipe Power System (HPS), which provides power only; and the Heatpipe Bimodal System (HBS), which provides both power and thermal propulsion. Both concepts have 10 important features. First, only existing technology and recently tested fuel forms are used. Second, fuel can be removed whenever desired, which greatly facilitates system fabrication and handling. Third, full electrically heated system testing of all modes is possible, with minimal operations required to replace the heaters with fuel and to ready the systemmore » for launch. Fourth, the systems are passively subcritical during launch accidents. Fifth, a modular approach is used, and most technical issues can be resolved with inexpensive module tests. Sixth, bonds between dissimilar metals are minimized. Seventh, there are no single-point failures during power mode operation. Eighth, the fuel burnup rate is quite low to help ensure {approx_gt}10-yr system life. Ninth, there are no pumped coolant loops, and the systems can be shut down and restarted without coolant freeze/thaw concerns. Finally, full ground nuclear test is not needed, and development costs will be low. One design for a low-power HPS uses SNAP-10A-style thermoelectric power converters to produce 5 kWe at a system mass of {approximately}500 kg. The unicouple thermoelectric converters have a hot-shoe temperature of 1275 K and reject waste heat at 775 K. This type of thermoelectric converter has been used extensively by the space program and has demonstrated an operational lifetime of decades. A core with a larger number of smaller modules (same overall size) can be used to provide up to 500 kWt to a power conversion subsystem, and a slightly larger core using a higher heatpipe to fuel ratio can provide {approx_gt}1 MWt. (Abstract Truncated)« less

Heatpipe space power and propulsion systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Houts, M.G.; Poston, D.I.; Ranken, W.A.

1995-12-01

Safe, reliable, low-mass space power and propulsion systems could have numerous civilian and military applications. This paper discusses two fission-powered concepts: The Heatpipe Power System (HPS), which provides power only; and the Heatpipe Bimodal System (HBS), which provides both power and thermal propulsion. Both concepts have 10 important features. First, only existing technology and recently tested fuel forms are used. Second, fuel can be removed whenever desired, which greatly facilitates system fabrication and handling. Third, full electrically heated system testing of all modes is possible, with minimal operations required to replace the heaters with fuel and to ready the systemmore » for launch. Fourth, the systems are passively subcritical during launch accidents. Fifth, a modular approach is used, and most technical issues can be resolved with inexpensive module tests. Sixth, bonds between dissimilar metals are minimized. Seventh, there are no single-point failures during power mode operation. Eighth, the fuel burnup rate is quite low to help ensure >10-yr system life. Ninth, there are no pumped coolant loops, and the systems can be shut down and restarted without coolant freeze/thaw concerns. Finally, full ground nuclear test is not needed, and development costs will be low. One design for a low-power HPS uses SNAP-10A-style thermoelectric power converters to produce 5 kWe at a system mass of {approximately}500 kg. The unicouple thermoelectric converters have a hot-shoe temperature of 1275 K and reject waste heat at 775 K. This type of thermoelectric converter has been used extensively by the space program and has demonstrated an operational lifetime of decades. A core with a larger number of smaller modules (same overall size) can be used to provide up to 500 kWt to a power conversion subsystem, and a slightly larger core using a higher heatpipe to fuel ratio can provide >1 MWt.« less

Modular interdependency in complex dynamical systems.

PubMed

Watson, Richard A; Pollack, Jordan B

2005-01-01

Herbert A. Simon's characterization of modularity in dynamical systems describes subsystems as having dynamics that are approximately independent of those of other subsystems (in the short term). This fits with the general intuition that modules must, by definition, be approximately independent. In the evolution of complex systems, such modularity may enable subsystems to be modified and adapted independently of other subsystems, whereas in a nonmodular system, modifications to one part of the system may result in deleterious side effects elsewhere in the system. But this notion of modularity and its effect on evolvability is not well quantified and is rather simplistic. In particular, modularity need not imply that intermodule dependences are weak or unimportant. In dynamical systems this is acknowledged by Simon's suggestion that, in the long term, the dynamical behaviors of subsystems do interact with one another, albeit in an "aggregate" manner--but this kind of intermodule interaction is omitted in models of modularity for evolvability. In this brief discussion we seek to unify notions of modularity in dynamical systems with notions of how modularity affects evolvability. This leads to a quantifiable measure of modularity and a different understanding of its effect on evolvability.

Quality of life and functional capacity outcomes in the MOMENTUM 3 trial at 6 months: A call for new metrics for left ventricular assist device patients.

PubMed

Cowger, Jennifer A; Naka, Yoshifumi; Aaronson, Keith D; Horstmanshof, Douglas; Gulati, Sanjeev; Rinde-Hoffman, Debbie; Pinney, Sean; Adatya, Sirtaz; Farrar, David J; Jorde, Ulrich P

2018-01-01

The Multicenter Study of MAGLEV Technology in Patients Undergoing Mechanical Circulatory Support Therapy with HeartMate 3 (MOMENTUM 3) clinical trial demonstrated improved 6-month event-free survival, but a detailed analysis of health-related quality of life (HR-QOL) and functional capacity (FC) was not presented. Further, the effect of early serious adverse events (SAEs) on these metrics and on the general ability to live well while supported with a left ventricular assist system (LVAS) warrants evaluation. FC (New York Heart Association [NYHA] and 6-minute walk test [6MWT]) and HR-QOL (European Quality of Life [EQ-5D-5L] and the Kansas City Cardiomyopathy [KCCQ]) assessments were obtained at baseline and 6 months after HeartMate 3 (HM3, n = 151; Abbott, Abbott Park, IL) or HeartMate II (HMII, n = 138; Abbott) implant as part of the MOMENTUM 3 clinical trial. Metrics were compared between devices and in those with and without events. The proportion of patients "living well on an LVAS" at 6 months, defined as alive with satisfactory FC (NYHA I/II or 6MWT > 300 meters) and HR-QOL (overall KCCQ > 50), was evaluated. Although the median (25th-75th percentile) patient KCCQ (change for HM3: +28 [10-46]; HMII: +29 [9-48]) and EQ-5D-5L (change for HM3: -1 [-5 to 0]; HMII: -2 [-6 to 0]) scores improved from baseline to 6 months (p < 0.05), there were no differences between devices (p > 0.05). Likewise, there was an equivalent improvement in 6MWT distance at 6 months in HM3 (+94 [1-274] meters] and HMII (+188[43-340 meters]) from baseline. In patients with SAEs (n = 188), 6MWTs increased from baseline (p < 0.001), but gains for both devices were less than those without SAE (HM3: +74 [-9 to 183] meters with SAE vs +140 [35-329] meters without SAE; HMII: +177 [47-356] meters with SAE vs +192 [23-337] meters without SAE, both p < 0.003). SAEs did not affect the 6-month HR-QOL scores. The "living well" end point was achieved in 145 HM3 (63%) and 120 HMII (68%) patients (p = 0.44). Gains in HR-QOL and FC were similar early after HM3 and HMII implant. 6MWT improvements were attenuated in patients experiencing SAEs, but HR-QOL metrics did not change. The development of left ventricular assist device-specific HR-QOL tools is needed to better characterize the effect of SAEs on a patient's well-being. MOMENTUM 3 clinical trial #NCT02224755. Copyright © 2018 International Society for the Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

Individual differences and time-varying features of modular brain architecture.

PubMed

Liao, Xuhong; Cao, Miao; Xia, Mingrui; He, Yong

2017-05-15

Recent studies have suggested that human brain functional networks are topologically organized into functionally specialized but inter-connected modules to facilitate efficient information processing and highly flexible cognitive function. However, these studies have mainly focused on group-level network modularity analyses using "static" functional connectivity approaches. How these extraordinary modular brain structures vary across individuals and spontaneously reconfigure over time remain largely unknown. Here, we employed multiband resting-state functional MRI data (N=105) from the Human Connectome Project and a graph-based modularity analysis to systematically investigate individual variability and dynamic properties in modular brain networks. We showed that the modular structures of brain networks dramatically vary across individuals, with higher modular variability primarily in the association cortex (e.g., fronto-parietal and attention systems) and lower variability in the primary systems. Moreover, brain regions spontaneously changed their module affiliations on a temporal scale of seconds, which cannot be simply attributable to head motion and sampling error. Interestingly, the spatial pattern of intra-subject dynamic modular variability largely overlapped with that of inter-subject modular variability, both of which were highly reproducible across repeated scanning sessions. Finally, the regions with remarkable individual/temporal modular variability were closely associated with network connectors and the number of cognitive components, suggesting a potential contribution to information integration and flexible cognitive function. Collectively, our findings highlight individual modular variability and the notable dynamic characteristics in large-scale brain networks, which enhance our understanding of the neural substrates underlying individual differences in a variety of cognition and behaviors. Copyright © 2017 Elsevier Inc. All rights reserved.

Modular Apparatus and Method for Attaching Multiple Devices

NASA Technical Reports Server (NTRS)

Okojie, Robert S (Inventor)

2015-01-01

A modular apparatus for attaching sensors and electronics is disclosed. The modular apparatus includes a square recess including a plurality of cavities and a reference cavity such that a pressure sensor can be connected to the modular apparatus. The modular apparatus also includes at least one voltage input hole and at least one voltage output hole operably connected to each of the plurality of cavities such that voltage can be applied to the pressure sensor and received from the pressure sensor.

Robotic hand with modular extensions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salisbury, Curt Michael; Quigley, Morgan

A robotic device is described herein. The robotic device includes a frame that comprises a plurality of receiving regions that are configured to receive a respective plurality of modular robotic extensions. The modular robotic extensions are removably attachable to the frame at the respective receiving regions by way of respective mechanical fuses. Each mechanical fuse is configured to trip when a respective modular robotic extension experiences a predefined load condition, such that the respective modular robotic extension detaches from the frame when the load condition is met.

Modular femoral neck fracture after primary total hip arthroplasty.

PubMed

Sotereanos, Nicholas G; Sauber, Timothy J; Tupis, Todd T

2013-01-01

The use of modular femoral stems in primary total hip arthroplasty has increased considerably in recent years. These modular components offer the surgeon the ability to independently alter version, offset, and length of the femoral component of a hip arthroplasty. This increases the surgeon's ability to accurately recreate the relevant anatomy but increases the possibilities of corrosion and fracture. Multiple case reports have highlighted fractures of these modular components. We present a case of a fracture of a modular design that has had no previously reported modular neck fractures. The patient was informed that data concerning the case would be submitted, and he consented. Copyright © 2013 Elsevier Inc. All rights reserved.

Modular properties of 6d (DELL) systems

NASA Astrophysics Data System (ADS)

Aminov, G.; Mironov, A.; Morozov, A.

2017-11-01

If super-Yang-Mills theory possesses the exact conformal invariance, there is an additional modular invariance under the change of the complex bare charge [InlineMediaObject not available: see fulltext.]. The low-energy Seiberg-Witten prepotential ℱ( a), however, is not explicitly invariant, because the flat moduli also change a - → a D = ∂ℱ/∂ a. In result, the prepotential is not a modular form and depends also on the anomalous Eisenstein series E 2. This dependence is usually described by the universal MNW modular anomaly equation. We demonstrate that, in the 6 d SU( N) theory with two independent modular parameters τ and \\widehat{τ} , the modular anomaly equation changes, because the modular transform of τ is accompanied by an ( N -dependent!) shift of \\widehat{τ} and vice versa. This is a new peculiarity of double-elliptic systems, which deserves further investigation.

Towards a Formal Basis for Modular Safety Cases

NASA Technical Reports Server (NTRS)

Denney, Ewen; Pai, Ganesh

2015-01-01

Safety assurance using argument-based safety cases is an accepted best-practice in many safety-critical sectors. Goal Structuring Notation (GSN), which is widely used for presenting safety arguments graphically, provides a notion of modular arguments to support the goal of incremental certification. Despite the efforts at standardization, GSN remains an informal notation whereas the GSN standard contains appreciable ambiguity especially concerning modular extensions. This, in turn, presents challenges when developing tools and methods to intelligently manipulate modular GSN arguments. This paper develops the elements of a theory of modular safety cases, leveraging our previous work on formalizing GSN arguments. Using example argument structures we highlight some ambiguities arising through the existing guidance, present the intuition underlying the theory, clarify syntax, and address modular arguments, contracts, well-formedness and well-scopedness of modules. Based on this theory, we have a preliminary implementation of modular arguments in our toolset, AdvoCATE.

Brain modularity controls the critical behavior of spontaneous activity.

PubMed

Russo, R; Herrmann, H J; de Arcangelis, L

2014-03-13

The human brain exhibits a complex structure made of scale-free highly connected modules loosely interconnected by weaker links to form a small-world network. These features appear in healthy patients whereas neurological diseases often modify this structure. An important open question concerns the role of brain modularity in sustaining the critical behaviour of spontaneous activity. Here we analyse the neuronal activity of a model, successful in reproducing on non-modular networks the scaling behaviour observed in experimental data, on a modular network implementing the main statistical features measured in human brain. We show that on a modular network, regardless the strength of the synaptic connections or the modular size and number, activity is never fully scale-free. Neuronal avalanches can invade different modules which results in an activity depression, hindering further avalanche propagation. Critical behaviour is solely recovered if inter-module connections are added, modifying the modular into a more random structure.

Feasibility and Reliability of Tests Measuring Health-Related Physical Fitness in Children with Moderate to Severe Levels of Intellectual Disability

ERIC Educational Resources Information Center

Wouters, Marieke; van der Zanden, Anna M.; Evenhuis, Heleen M.; Hilgenkamp, Thessa I. M.

2017-01-01

Physical fitness is an important marker for health. In this study we investigated the feasibility and reliability of health-related physical fitness tests in children with moderate to severe levels of intellectual disability. Thirty-nine children (2-18 yrs) performed tests for muscular strength and endurance, the modified 6-minute walk test (6mwt)…

EBR-II high-ramp transients under computer control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Forrester, R.J.; Larson, H.A.; Christensen, L.J.

1983-01-01

During reactor run 122, EBR-II was subjected to 13 computer-controlled overpower transients at ramps of 4 MWt/s to qualify the facility and fuel for transient testing of LMFBR oxide fuels as part of the EBR-II operational-reliability-testing (ORT) program. A computer-controlled automatic control-rod drive system (ACRDS), designed by EBR-II personnel, permitted automatic control on demand power during the transients.

Perceived Social Support and Markers of Heart Failure Severity

DTIC Science & Technology

2011-09-09

necessary for altering threat evaluation and enhancing self - esteem . Informational support, also referred to as appraisal support, describes the availability...1994). Social connections have been shown to enhance mood, reinforce self - esteem , and introduce adaptive coping resources for stress (Spiegel, Bloom...6MWT), self -reported symptoms as indicated by the Kansas City Cardiomyopathy Questionnaire (KCCQ), and levels of the biomarker BNP). Methods. Ninety

Physical Functional Capacity and C-Reactive Protein in Schizophrenia.

PubMed

Szortyka, Michele Fonseca Vieira; Cristiano, Viviane Batista; Ceresér, Keila Maria; Francesconi, Lenise Petter; Lobato, Maria Inês; Gama, Clarissa; Belmonte-de-Abreu, Paulo

2016-01-01

Schizophrenia is a severe, debilitating mental disorder that affects both the physical health and the functional capacity of patients, causing great impairment throughout the life course. Although physical and cognitive impairments may represent different expressions of a single systemic inflammatory process, little is known about the relationship between motor function and schizophrenia. To evaluate physical functional capacity in patients with schizophrenia and ascertain whether it correlates with markers of inflammation, disease severity, and pharmacotherapy. Cross-sectional study using a convenience sampling strategy. Forty patients with stable schizophrenia, undergoing treatment, were recruited from the Outpatient Program of Hospital de Clínicas de Porto Alegre, University Hospital linked to Public Health System. Physical functional capacity was assessed by the 6-min walk test (6MWT), and inflammatory markers were measured by C-reactive protein (CRP) and Von Willebrand factor. Mean functional capacity and clinical variables differed among patients and Brazilian population regarding heart rate (p = 0.004), diastolic (p = 0.001) and systolic (p < 0.001) blood pressure, respiratory rate (p < 0.001), CRP (p = 0.015), Borg Scale of Perceived Exertion scores (BSPE) (p < 0.001), and 6MWT both in men (p < 0.001) and women (p = 0.024). Additionally, 6MWT and dyspnea in BSPE were positively associated with CRP (r = -0.369, p = 0.019) and (r = -0.376, p = 0.017) and (r = 0.354, p = 0.025 and r = 0.535, p < 0.001, respectively). The present study detected significant association between measures of functional impairment and markers of inflammation, especially elevated CRP in a group of stable outpatients with DSM-IV and ICD10 diagnosis of schizophrenia. Possible explanations for the associations could be linked to continued use of antipsychotics, although underlying neuroinflammatory mechanisms directly related to illness (schizophrenia) could not be ruled out. The findings of this study expand evidences of neuroinflammation to systemic inflammation in schizophrenia linking it to alterations of physical functional capacity and point to the need of additional studies exploring general inflammation and novel therapeutic interventions.

Ankle voluntary movement enhancement following robotic-assisted locomotor training in spinal cord injury

PubMed Central

2014-01-01

Background In incomplete spinal cord injury (iSCI), sensorimotor impairments result in severe limitations to ambulation. To improve walking capacity, physical therapies using robotic-assisted locomotor devices, such as the Lokomat, have been developed. Following locomotor training, an improvement in gait capabilities—characterized by increases in the over-ground walking speed and endurance—is generally observed in patients. To better understand the mechanisms underlying these improvements, we studied the effects of Lokomat training on impaired ankle voluntary movement, known to be an important limiting factor in gait for iSCI patients. Methods Fifteen chronic iSCI subjects performed twelve 1-hour sessions of Lokomat training over the course of a month. The voluntary movement was qualified by measuring active range of motion, maximal velocity peak and trajectory smoothness for the spastic ankle during a movement from full plantar-flexion (PF) to full dorsi-flexion (DF) at the patient’s maximum speed. Dorsi- and plantar-flexor muscle strength was quantified by isometric maximal voluntary contraction (MVC). Clinical assessments were also performed using the Timed Up and Go (TUG), the 10-meter walk (10MWT) and the 6-minute walk (6MWT) tests. All evaluations were performed both before and after the training and were compared to a control group of fifteen iSCI patients. Results After the Lokomat training, the active range of motion, the maximal velocity, and the movement smoothness were significantly improved in the voluntary movement. Patients also exhibited an improvement in the MVC for their ankle dorsi- and plantar-flexor muscles. In terms of functional activity, we observed an enhancement in the mobility (TUG) and the over-ground gait velocity (10MWT) with training. Correlation tests indicated a significant relationship between ankle voluntary movement performance and the walking clinical assessments. Conclusions The improvements of the kinematic and kinetic parameters of the ankle voluntary movement, and their correlation with the functional assessments, support the therapeutic effect of robotic-assisted locomotor training on motor impairment in chronic iSCI. PMID:24684813

Effects of vitamin C, vitamin E, zinc gluconate, and selenomethionine supplementation on muscle function and oxidative stress biomarkers in patients with facioscapulohumeral dystrophy: a double-blind randomized controlled clinical trial.

PubMed

Passerieux, Emilie; Hayot, Maurice; Jaussent, Audrey; Carnac, Gilles; Gouzi, Fares; Pillard, Fabien; Picot, Marie-Christine; Böcker, Koen; Hugon, Gerald; Pincemail, Joel; Defraigne, Jean O; Verrips, Theo; Mercier, Jacques; Laoudj-Chenivesse, Dalila

2015-04-01

Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant disease characterized by progressive weakness and atrophy of specific skeletal muscles. As growing evidence suggests that oxidative stress may contribute to FSHD pathology, antioxidants that might modulate or delay oxidative insults could help in maintaining FSHD muscle function. Our primary objective was to test whether oral administration of vitamin C, vitamin E, zinc gluconate, and selenomethionine could improve the physical performance of patients with FSHD. Adult patients with FSHD (n=53) were enrolled at Montpellier University Hospital (France) in a randomized, double-blind, placebo-controlled pilot clinical trial. Patients were randomly assigned to receive 500 mg vitamin C, 400mg vitamin E, 25mg zinc gluconate and 200 μg selenomethionine (n=26), or matching placebo (n=27) once a day for 17 weeks. Primary outcomes were changes in the two-minute walking test (2-MWT), maximal voluntary contraction, and endurance limit time of the dominant and nondominant quadriceps (MVCQD, MVCQND, TlimQD, and TlimQND, respectively) after 17 weeks of treatment. Secondary outcomes were changes in the antioxidant status and oxidative stress markers. Although 2-MWT, MVCQ, and TlimQ were all significantly improved in the supplemented group at the end of the treatment compared to baseline, only MVCQ and TlimQ variations were significantly different between groups (MVCQD: P=0.011; MVCQND: P=0.004; TlimQD: P=0.028; TlimQND: P=0.011). Similarly, the vitamin C (P<0.001), vitamin E as α-tocopherol (P<0.001), vitamin C/vitamin E ratio (P=0.017), vitamin E γ/α ratio (P=0.022) and lipid peroxides (P<0.001) variations were significantly different between groups. In conclusion, vitamin E, vitamin C, zinc, and selenium supplementation has no significant effect on the 2-MWT, but improves MVCQ and TlimQ of both quadriceps by enhancing the antioxidant defenses and reducing oxidative stress. This trial was registered at clinicaltrials.gov (number: NCT01596803). Copyright © 2014 Elsevier Inc. All rights reserved.

Can Exercise Capacity Assessed by the 6 Minute Walk Test Predict the Development of Major Adverse Cardiac Events in Patients with STEMI after Fibrinolysis?

PubMed Central

Hassan, Ayman K. M.; Dimitry, Salwa R.; Agban, George W.

2014-01-01

Background To assess the added value of the 6 minute walk test distance (6MWTD) in the risk-stratification methods for patients with ST -segment elevation myocardial infarction (STEMI) treated with fibrinolysis. Methodology/Principal Findings This is a prospective cohort study of one hundred consecutive patients with STEMI, who had received fibrinolysis, at Assuit University Hospital. All patients underwent 6MWT pre- discharge and were followed up for 3 months to monitor the incidence of major adverse cardiac events (MACE). Patients were divided into 3 groups according to the level of 6MWTD (level I>450 m, level II = 300–450 m and level III<300 m). Among the study population, the median 6MWT distance was 370 meters (interquartile range 162–462). The mean age was 60.9±10.7 years, 71.9% of them were males, 2/3 had anterior MI. only 10.5% had successful thrombolysis. Compared to patients in level I (>450 m), patients in level III (<300 m) were more likely to have clinical risk factors as hypertension, diabetes and impaired renal function. The patient's mean TIMI score was 3.4±2.2, the mean GRACE score was 150.5±27.7. There was a significant negative correlation between the 6 MWTD and GRACE risk score (r = −0.80, p<0.001). At 3 months of follow-up, 51% had MACE including 16% were dead. Multivariate logistic regression analysis identified that the GRACE risk score and 6MWT distance levels were the best predictors of the MACE at 3 month of follow up. The incidence of MACE was 4 times higher in patients with high GRACE risk score who couldn't walk more than 300 meters (OR = 4.66, 95% CI = 1.1–14.5, p = 0.006). Conclusions/Significance In patients with STEMI treated with fibrinolysis, the addition of 6MWTD assessment pre-discharge to the traditional GRACE risk score improved the risk prediction of cardiovascular events at 3 month follow up. PMID:24905094

High-intensity body weight training is comparable to combined training in changes in muscle mass, physical performance, inflammatory markers and metabolic health in postmenopausal women at high risk for type 2 diabetes mellitus: A randomized controlled clinical trial.

PubMed

Martins, Fernanda Maria; de Paula Souza, Aletéia; Nunes, Paulo Ricardo Prado; Michelin, Márcia Antoniazi; Murta, Eddie Fernando Candido; Resende, Elisabete Aparecida Mantovani Rodrigues; de Oliveira, Erick Prado; Orsatti, Fábio Lera

2018-07-01

This study compared the effects of 12 weeks of high-intensity interval body weight training (HIBWT) with combined training (COMT; aerobic and resistance exercises on body composition, a 6-minute walk test (6MWT; physical performance), insulin resistance (IR) and inflammatory markers in postmenopausal women (PW) at high risk of type 2 diabetes mellitus (TDM2). In this randomized controlled clinical study, 16 PW at high risk of TDM2 were randomly allocated into two groups: HIBWT (n = 8) and COMT (n = 8). The HIBWT group performed a training protocol (length time ~28 min) consisting of ten sets of 60 s of high intensity exercise interspersed by a recovery period of 60 s of low intensity exercise. The COMT group performed a training protocol (length time ~60 min) consisting of a 30 min walk of moderate intensity following by five resistance exercises. All training sessions were performed in the university gym facility three days a week (no consecutive days) for 12 weeks. All outcomes (body composition, muscle function, and IR and inflammatory markers) were assessed at the baseline and at the end of the study. Both groups increased (P < 0.05) muscle mass index (MMI), 6MWT, and interleukin 1 receptor antagonist and decreased fasting glucose, glycated hemoglobin , Insulin, HOMA-IR, and monocyte chemoattractant protein-1 (trend, P = 0.056). HIBWT effects were indistinguishable (P > 0.05) from the effects of COMT. There was a significant (P < 0.05) interaction of time by the group in muscle strength, indicating that only the COMT increased the muscle strength. This study suggests that changes in HOMA, IL-1ra, 6MWT, and MMI with HITBW are similar when compared to COMT in PW at high risk of TDM2. The patients were part of a 12-week training study (ClinicalTrials.gov Identifier: NCT03200639). Copyright © 2018 Elsevier Inc. All rights reserved.

The 6-minute walk test in chronic respiratory failure: does observed or predicted walk distance better reflect patient functional status?

PubMed

Güngör, Gökay; Karakurt, Zuhal; Adigüzel, Nalan; Aydin, Rüya Evin; Balci, Merih Kalamanoğlu; Saltürk, Cüneyt; Sancar, Raziye; Solmaz, Suat; Moçin, Özlem Yazicioğlu

2013-05-01

Acquiring 6-min walk test (6MWT) data from patients undergoing noninvasive mechanical ventilation due to chronic hypercapnic respiratory failure is limited. We aimed to assess whether the actual 6-min walk distance (6MWD) or the percent predicted 6MWD is a better reflection of the respiratory function of patients using home noninvasive ventilation (NIV) due to chronic hypercapnic respiratory failure. This was a cross-sectional observational study. The 6MWT was performed in subjects using home NIV. Diagnoses were grouped as COPD, obesity hypoventilation syndrome (OHS), kyphoscoliosis, and parenchymal lung disease. Sex, age, and body mass index (BMI) were used to calculate ideal 6MWD. Male: 1,140 m - (5.61 × BMI) - (6.94 × age), and subtract 153 m for the lower limit of normal. Female: 1,017 m - (6.24 × BMI) - (5.83 × age), and subtract 139 m for the lower limit of normal. The 6MWD and percent-of-predicted 6MWD were compared relative to arterial blood gas, spirometry values, and diagnosis. The 6MWT was performed in 144 subjects, median (IQR) age 62 y (55-71 y). The male/female ratio, median (IQR) 6MWD, and percent-of-predicted 6MWD values were: COPD 32/6, 316 m (226-390 m), and 59.4% (42.5-68.9%); OHS 24/28, 303 m (240-362 m), and 73.0% (63.0-82.0%); kyphoscoliosis 16/7, 420 m (318-462 m), and 70.5% (56.0-75.2%); and parenchymal lung disease 19/12, 333 m (273-372 m), and 67.1% (46.7-74.7%). The correlation of percent-of-predicted 6MWD with spirometry and arterial blood gas values were better than with the actual 6MWD. The percent-of-predicted 6MWD was better correlated with respiratory function than actual 6MWD for subjects using home NIV due to chronic hypercapnic respiratory failure with COPD, OHS, kyphoscoliosis, and parenchymal lung disease.

Socializing by Day May Affect Performance by Night: Vulnerability to Sleep Deprivation is Differentially Mediated by Social Exposure in Extraverts vs Introverts

PubMed Central

Rupp, Tracy L.; Killgore, William D.S.; Balkin, Thomas J.

2010-01-01

Study Objectives: To examine the effects of socially enriched versus socially impoverished environments on performance and alertness decline during sleep deprivation in extraverts versus introverts. Design: Participants (n = 29 men, n = 19 women) were assigned to socially enriched (n = 24; 13 introverts, 11 extraverts) or socially impoverished (n = 24; 12 introverts, 12 extraverts) conditions (activities matched) for 12 hours (1000–2200) on Day 1 followed by 22 hours of sleep deprivation (2200-2000; 36 h awake total), monitored by actigraphy. The median split of volunteers' Eysenck Extraversion scores was used for extravert/introvert categorization. The Psychomotor Vigilance Task (PVT), modified Maintenance of Wakefulness Test (MWT), and Stanford Sleepiness Scale (SSS) were administered every 2 hours throughout. PVT speed, transformed lapses, modified MWT sleep-onset latency, and SSS were analyzed using mixed-model analyses of variance, with covariates of age and total actigraphic activity during enrichment or impoverishment. Setting: Residential sleep/performance testing facility. Participants: Forty-eight healthy adults (aged 18–39). Interventions: Twelve hours of socially enriched or isolated environments in extraverts and introverts prior to sleep deprivation. Results Social experience interacted with personality type to affect alertness and vigilance. Social enrichment, as compared with social impoverishment, was associated with more PVT lapses at 04:00 overall. Similarly, following social enrichment, PVT speed was significantly slower among extraverts than among introverts during sleep deprivation, but no personality-group differences emerged following social impoverishment. MWT sleep latency and SSS subjective sleepiness did not show significant personality or social-condition effects during sleep deprivation. Conclusions: The effect of social exposure on vulnerability or resiliency to sleep deprivation was modulated by introversion and extraversion. Extraverts exposed to social environments were more vulnerable to subsequent sleep deprivation than were introverts. Citation: Rupp TL; Killgore WDS; Balkin TJ. Socializing by day may affect performance by night: vulnerability to sleep deprivation is differentially mediated by social exposure in extraverts vs introverts. SLEEP 2010;33(11):1475-1485. PMID:21102989

"Reliability of the Norwegian version of the short physical performance battery in older people with and without dementia".

PubMed

Olsen, Cecilie Fromholt; Bergland, Astrid

2017-06-09

The purpose of the study was to establish the test-retest reliability of the Norwegian version of the Short Physical Performance Battery (SPPB). This was a cross- sectional reliability study. A convenience sample of 61 older adults with a mean age of 88.4(8.1) was tested by two different physiotherapists at two time points. The mean time interval between tests was 2.5 days. The Intraclass Correlation Coefficient model 3.1 (ICC, 3.1) with 95% confidence intervals as well as the weighted Kappa (K) were used as measures of relative reliability. The Standard Error of Measurement (SEM) and Minimal Detectable Change (MDC) were used to measure absolute reliability. The results were also analyzed for a subgroup of 24 older people with dementia. The ICC reflected high relative reliability for the SPPB summary score and the 4 m walk test (4mwt), both for the total sample (ICC = 0.92, and 0.91 respectively)) and for the subgroup with dementia (ICC = 0.84 and 0.90 respectively). Furthermore, weighted Ks for the SPPB subscales were 0.64 for the chair stand, 0.80 for gait and 0.52 for balance for the total sample and almost identical for the subgroup with dementia. MDC-values at the 95% confidence intervals (MDC95) were calculated at 0.8 for the total score of SPPB and 0.39 m/s for the 4mwt in the total sample. For the subgroup with dementia MDC95 was 1.88 for the total score of SPPB and 0.28 m/s for 4mwt. The SPPB total score and the timed walking test showed overall high relative and absolute reliability for the total sample indicating that the Norwegian version of the SPPB is reliable when used by trained physiotherapists with older people. The reliability of the Norwegian SPPB in older people with dementia seems high, but due to a small sample size this needs further investigation.

The role of postural control in the association between aerobic capacity and walking capacity in chronic stroke: a cross-sectional analysis.

PubMed

Outermans, Jacqueline C; van de Port, Ingrid; Kwakkel, Gert; Visser-Meily, Johanna M; Wittink, Harriet

2018-03-12

Reports on the association between aerobic capacity and walking capacity in people after stroke show disparate results. To determine (1) if the predictive validity of peak oxygen uptake (VO2peak) for walking capacity post stroke is different from that of maximal oxygen uptake (VO2max) and (2) if postural control, hemiplegic lower extremity muscle strength, age and gender distort the association between aerobic capacity and walking capacity. Cross-sectional study. General community in Utrecht, the Netherlands. Community-dwelling people more than three months after stroke. Measurement of aerobic capacity were performed with cardiopulmonary exercise testing (CPET) and differentiated between the achievement of VO2peak or VO2max. Measurement of walking capacity with the Six Minute Walk Test (6MWT), postural control with the Performance Oriented Mobility Assessment (POMA) and hemiplegic lower extremity muscle strength with the Motricity Index (MI-LE). Fifty-one out of 62 eligible participants, aged 64.7 (±12.5) years were included. Analysis of covariance (ANCOVA) showed a nonsignificant difference between the predictive validities of VO2max (N = 22, β = 0.56; 95%CI 0.12 - 0.97) and VO2peak (N = 29, β = 0.72; 95%CI 0.38 - 0.92). Multiple regression analysis of the pooled sample showed a significant decrease in the β value of VO2peak (21.6%) for the 6MWT when adding the POMA as a covariate in the association model. VO2peak remained significantly related to 6MWT after correcting for the POMA (β = 0.56 (95%CI 0.39 - 0.75)) CONCLUSIONS: The results suggest similar predictive validity of aerobic capacity for walking capacity in participants achieving VO2max compared to those only achieving VO2peak. Postural control confounds the association between aerobic capacity and walking capacity. Aerobic capacity remains a valid predictor of walking capacity. Aerobic capacity is an important factor associated with walking capacity after stroke. However, to understand this relationship, postural control needs to be measured. Both aerobic capacity and postural control may need to be addressed during interventions aiming to improve walking capacity after stroke.

Why Go Modular? A Review of Modular A-Level Mathematics.

ERIC Educational Resources Information Center

Taverner, Sally; Wright, Martin

1997-01-01

Attitudes, academic intentions, and attainment of students gaining a grade in A-level (Advanced level) mathematics were compared for those who followed a modular course and those assessed at the end of two years of study. Overall, the final grades of those assessed modularly were half a grade higher. (JOW)

On Classification of Modular Categories by Rank: Table A.1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bruillard, Paul; Ng, Siu-Hung; Rowell, Eric C.

2016-04-10

The feasibility of a classification-by-rank program for modular categories follows from the Rank-Finiteness Theorem. We develop arithmetic, representation theoretic and algebraic methods for classifying modular categories by rank. As an application, we determine all possible fusion rules for all rank=5 modular categories and describe the corresponding monoidal equivalence classes.

46 CFR 181.450 - Independent modular smoke detecting units.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 7 2013-10-01 2013-10-01 false Independent modular smoke detecting units. 181.450... Independent modular smoke detecting units. (a) An independent modular smoke detecting unit must: (1) Meet UL 217 (incorporated by reference, see 46 CFR 175.600) and be listed as a “Single Station Smoke detector...

46 CFR 181.450 - Independent modular smoke detecting units.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 7 2012-10-01 2012-10-01 false Independent modular smoke detecting units. 181.450... Independent modular smoke detecting units. (a) An independent modular smoke detecting unit must: (1) Meet UL 217 (incorporated by reference, see 46 CFR 175.600) and be listed as a “Single Station Smoke detector...

46 CFR 181.450 - Independent modular smoke detecting units.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Independent modular smoke detecting units. 181.450... Independent modular smoke detecting units. (a) An independent modular smoke detecting unit must: (1) Meet UL 217 (incorporated by reference, see 46 CFR 175.600) and be listed as a “Single Station Smoke detector...

46 CFR 181.450 - Independent modular smoke detecting units.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Independent modular smoke detecting units. 181.450... Independent modular smoke detecting units. (a) An independent modular smoke detecting unit must: (1) Meet UL 217 (incorporated by reference, see 46 CFR 175.600) and be listed as a “Single Station Smoke detector...

46 CFR 181.450 - Independent modular smoke detecting units.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 7 2014-10-01 2014-10-01 false Independent modular smoke detecting units. 181.450... Independent modular smoke detecting units. (a) An independent modular smoke detecting unit must: (1) Meet UL 217 (incorporated by reference, see 46 CFR 175.600) and be listed as a “Single Station Smoke detector...

Unraveling the disease consequences and mechanisms of modular structure in animal social networks

PubMed Central

Leu, Stephan T.; Cross, Paul C.; Hudson, Peter J.; Bansal, Shweta

2017-01-01

Disease risk is a potential cost of group living. Although modular organization is thought to reduce this cost in animal societies, empirical evidence toward this hypothesis has been conflicting. We analyzed empirical social networks from 43 animal species to motivate our study of the epidemiological consequences of modular structure in animal societies. From these empirical studies, we identified the features of interaction patterns associated with network modularity and developed a theoretical network model to investigate when and how subdivisions in social networks influence disease dynamics. Contrary to prior work, we found that disease risk is largely unaffected by modular structure, although social networks beyond a modular threshold experience smaller disease burden and longer disease duration. Our results illustrate that the lowering of disease burden in highly modular social networks is driven by two mechanisms of modular organization: network fragmentation and subgroup cohesion. Highly fragmented social networks with cohesive subgroups are able to structurally trap infections within a few subgroups and also cause a structural delay to the spread of disease outbreaks. Finally, we show that network models incorporating modular structure are necessary only when prior knowledge suggests that interactions within the population are highly subdivided. Otherwise, null networks based on basic knowledge about group size and local contact heterogeneity may be sufficient when data-limited estimates of epidemic consequences are necessary. Overall, our work does not support the hypothesis that modular structure universally mitigates the disease impact of group living. PMID:28373567

Unraveling the disease consequences and mechanisms of modular structure in animal social networks

USGS Publications Warehouse

Sah, Pratha; Leu, Stephan T.; Cross, Paul C.; Hudson, Peter J.; Bansal, Shweta

2017-01-01

Disease risk is a potential cost of group living. Although modular organization is thought to reduce this cost in animal societies, empirical evidence toward this hypothesis has been conflicting. We analyzed empirical social networks from 43 animal species to motivate our study of the epidemiological consequences of modular structure in animal societies. From these empirical studies, we identified the features of interaction patterns associated with network modularity and developed a theoretical network model to investigate when and how subdivisions in social networks influence disease dynamics. Contrary to prior work, we found that disease risk is largely unaffected by modular structure, although social networks beyond a modular threshold experience smaller disease burden and longer disease duration. Our results illustrate that the lowering of disease burden in highly modular social networks is driven by two mechanisms of modular organization: network fragmentation and subgroup cohesion. Highly fragmented social networks with cohesive subgroups are able to structurally trap infections within a few subgroups and also cause a structural delay to the spread of disease outbreaks. Finally, we show that network models incorporating modular structure are necessary only when prior knowledge suggests that interactions within the population are highly subdivided. Otherwise, null networks based on basic knowledge about group size and local contact heterogeneity may be sufficient when data-limited estimates of epidemic consequences are necessary. Overall, our work does not support the hypothesis that modular structure universally mitigates the disease impact of group living.

Unraveling the disease consequences and mechanisms of modular structure in animal social networks.

PubMed

Sah, Pratha; Leu, Stephan T; Cross, Paul C; Hudson, Peter J; Bansal, Shweta

2017-04-18

Disease risk is a potential cost of group living. Although modular organization is thought to reduce this cost in animal societies, empirical evidence toward this hypothesis has been conflicting. We analyzed empirical social networks from 43 animal species to motivate our study of the epidemiological consequences of modular structure in animal societies. From these empirical studies, we identified the features of interaction patterns associated with network modularity and developed a theoretical network model to investigate when and how subdivisions in social networks influence disease dynamics. Contrary to prior work, we found that disease risk is largely unaffected by modular structure, although social networks beyond a modular threshold experience smaller disease burden and longer disease duration. Our results illustrate that the lowering of disease burden in highly modular social networks is driven by two mechanisms of modular organization: network fragmentation and subgroup cohesion. Highly fragmented social networks with cohesive subgroups are able to structurally trap infections within a few subgroups and also cause a structural delay to the spread of disease outbreaks. Finally, we show that network models incorporating modular structure are necessary only when prior knowledge suggests that interactions within the population are highly subdivided. Otherwise, null networks based on basic knowledge about group size and local contact heterogeneity may be sufficient when data-limited estimates of epidemic consequences are necessary. Overall, our work does not support the hypothesis that modular structure universally mitigates the disease impact of group living.

Modular architecture of protein structures and allosteric communications: potential implications for signaling proteins and regulatory linkages

PubMed Central

del Sol, Antonio; Araúzo-Bravo, Marcos J; Amoros, Dolors; Nussinov, Ruth

2007-01-01

Background Allosteric communications are vital for cellular signaling. Here we explore a relationship between protein architectural organization and shortcuts in signaling pathways. Results We show that protein domains consist of modules interconnected by residues that mediate signaling through the shortest pathways. These mediating residues tend to be located at the inter-modular boundaries, which are more rigid and display a larger number of long-range interactions than intra-modular regions. The inter-modular boundaries contain most of the residues centrally conserved in the protein fold, which may be crucial for information transfer between amino acids. Our approach to modular decomposition relies on a representation of protein structures as residue-interacting networks, and removal of the most central residue contacts, which are assumed to be crucial for allosteric communications. The modular decomposition of 100 multi-domain protein structures indicates that modules constitute the building blocks of domains. The analysis of 13 allosteric proteins revealed that modules characterize experimentally identified functional regions. Based on the study of an additional functionally annotated dataset of 115 proteins, we propose that high-modularity modules include functional sites and are the basic functional units. We provide examples (the Gαs subunit and P450 cytochromes) to illustrate that the modular architecture of active sites is linked to their functional specialization. Conclusion Our method decomposes protein structures into modules, allowing the study of signal transmission between functional sites. A modular configuration might be advantageous: it allows signaling proteins to expand their regulatory linkages and may elicit a broader range of control mechanisms either via modular combinations or through modulation of inter-modular linkages. PMID:17531094

Modular assembly for supporting, straining, and directing flow to a core in a nuclear reactor

DOEpatents

Pennell, William E.

1977-01-01

A reactor core support arrangement for supporting, straining, and providing fluid flow to the core and periphery of a nuclear reactor during normal operation. A plurality of removable inlet modular units are contained within permanent liners in the lower supporting plate of the reactor vessel lower internals. During normal operation (1) each inlet modular unit directs main coolant flow to a plurality of core assemblies, the latter being removably supported in receptacles in the upper portion of the modular unit and (2) each inlet modular unit may direct bypass flow to a low pressure annular region of the reactor vessel. Each inlet modular unit may include special fluid seals interposed between mating surfaces of the inlet modular units and the core assemblies and between the inlet modular units and the liners, to minimize leakage and achieve an hydraulic balance. Utilizing the hydraulic balance, the modular units are held in the liners and the assemblies are held in the modular unit receptacles by their own respective weight. Included as part of the permanent liners below the horizontal support plate are generally hexagonal axial debris barriers. The axial debris barriers collectively form a bottom boundary of a secondary high pressure plenum, the upper boundary of which is the bottom surface of the horizontal support plate. Peripheral liners include radial debris barriers which collectively form a barrier against debris entry radially. During normal operation primary coolant inlet openings in the liner, below the axial debris barriers, pass a large amount of coolant into the inlet modular units, and secondary coolant inlet openings in the portion of the liners within the secondary plenum pass a small amount of coolant into the inlet modular units. The secondary coolant inlet openings also provide alternative coolant inlet flow paths in the unlikely event of blockage of the primary inlet openings. The primary inlet openings have characteristics which limit the entry of debris and minimize the potential for debris entering the primary inlets blocking the secondary inlets from inside the modular unit.

AGR-1 Compact 1-3-1 Post-Irradiation Examination Results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Demkowicz, Paul Andrew

The Advanced Gas Reactor (AGR) Fuel Development and Qualification Program was established to perform the requisite research and development on tristructural isotropic (TRISO) coated particle fuel to support deployment of a high-temperature gas-cooled reactor (HTGR). The work continues as part of the Advanced Reactor Technologies (ART) TRISO Fuel program. The overarching program goal is to provide a baseline fuel qualification data set to support licensing and operation of an HTGR. To achieve these goals, the program includes the elements of fuel fabrication, irradiation, post-irradiation examination (PIE) and safety testing, fuel performance modeling, and fission product transport (INL 2015). A seriesmore » of fuel irradiation experiments is being planned and conducted in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL). These experiments will provide data on fuel performance under irradiation, support fuel process development, qualify the fuel for normal operating conditions, provide irradiated fuel for safety testing, and support the development of fuel performance and fission product transport models. The first of these irradiation tests, designated AGR-1, began in the ATR in December 2006 and ended in November 2009. This experiment was conducted primarily to act as a shakedown test of the multicapsule test train design and provide early data on fuel performance for use in fuel fabrication process development. It also provided samples for post-irradiation safety testing, where fission product retention of the fuel at high temperatures will be experimentally measured. The capsule design and details of the AGR-1 experiment have been presented previously (Grover, Petti, and Maki 2010, Maki 2009).« less

AGR-1 Compact 5-3-1 Post-Irradiation Examination Results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Demkowicz, Paul; Harp, Jason; Winston, Phil

The Advanced Gas Reactor (AGR) Fuel Development and Qualification Program was established to perform the requisite research and development on tristructural isotropic (TRISO) coated particle fuel to support deployment of a high-temperature gas-cooled reactor (HTGR). The work continues as part of the Advanced Reactor Technologies (ART) TRISO Fuel program. The overarching program goal is to provide a baseline fuel qualification data set to support licensing and operation of an HTGR. To achieve these goals, the program includes the elements of fuel fabrication, irradiation, post-irradiation examination (PIE) and safety testing, fuel performance, and fission product transport (INL 2015). A series ofmore » fuel irradiation experiments is being planned and conducted in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL). These experiments will provide data on fuel performance under irradiation, support fuel process development, qualify the fuel for normal operating conditions, provide irradiated fuel for safety testing, and support the development of fuel performance and fission product transport models. The first of these irradiation tests, designated AGR-1, began in the ATR in December 2006 and ended in November 2009. This experiment was conducted primarily to act as a shakedown test of the multicapsule test train design and provide early data on fuel performance for use in fuel fabrication process development. It also provided samples for post-irradiation safety testing, where fission product retention of the fuel at high temperatures will be experimentally measured. The capsule design and details of the AGR-1 experiment have been presented previously.« less

Portable modular detection system

DOEpatents

Brennan, James S [Rodeo, CA; Singh, Anup [Danville, CA; Throckmorton, Daniel J [Tracy, CA; Stamps, James F [Livermore, CA

2009-10-13

Disclosed herein are portable and modular detection devices and systems for detecting electromagnetic radiation, such as fluorescence, from an analyte which comprises at least one optical element removably attached to at least one alignment rail. Also disclosed are modular detection devices and systems having an integrated lock-in amplifier and spatial filter and assay methods using the portable and modular detection devices.

Modularity-like objective function in annotated networks

NASA Astrophysics Data System (ADS)

Xie, Jia-Rong; Wang, Bing-Hong

2017-12-01

We ascertain the modularity-like objective function whose optimization is equivalent to the maximum likelihood in annotated networks. We demonstrate that the modularity-like objective function is a linear combination of modularity and conditional entropy. In contrast with statistical inference methods, in our method, the influence of the metadata is adjustable; when its influence is strong enough, the metadata can be recovered. Conversely, when it is weak, the detection may correspond to another partition. Between the two, there is a transition. This paper provides a concept for expanding the scope of modularity methods.

Modular organization and hospital performance.

PubMed

Kuntz, Ludwig; Vera, Antonio

2007-02-01

The concept of modularization represents a modern form of organization, which contains the vertical disaggregation of the firm and the use of market mechanisms within hierarchies. The objective of this paper is to examine whether the use of modular structures has a positive effect on hospital performance. The empirical section makes use of multiple regression analyses and leads to the main result that modularization does not have a positive effect on hospital performance. However, the analysis also finds out positive efficiency effects of two central ideas of modularization, namely process orientation and internal market mechanisms.

Modular analysis of biological networks.

PubMed

Kaltenbach, Hans-Michael; Stelling, Jörg

2012-01-01

The analysis of complex biological networks has traditionally relied on decomposition into smaller, semi-autonomous units such as individual signaling pathways. With the increased scope of systems biology (models), rational approaches to modularization have become an important topic. With increasing acceptance of de facto modularity in biology, widely different definitions of what constitutes a module have sparked controversies. Here, we therefore review prominent classes of modular approaches based on formal network representations. Despite some promising research directions, several important theoretical challenges remain open on the way to formal, function-centered modular decompositions for dynamic biological networks.

Full characterization of modular values for finite-dimensional systems

NASA Astrophysics Data System (ADS)

Ho, Le Bin; Imoto, Nobuyuki

2016-06-01

Kedem and Vaidman obtained a relationship between the spin-operator modular value and its weak value for specific coupling strengths [14]. Here we give a general expression for the modular value in the n-dimensional Hilbert space using the weak values up to (n - 1)th order of an arbitrary observable for any coupling strength, assuming non-degenerated eigenvalues. For two-dimensional case, it shows a linear relationship between the weak value and the modular value. We also relate the modular value of the sum of observables to the weak value of their product.

On the role of sparseness in the evolution of modularity in gene regulatory networks

PubMed Central

2018-01-01

Modularity is a widespread property in biological systems. It implies that interactions occur mainly within groups of system elements. A modular arrangement facilitates adjustment of one module without perturbing the rest of the system. Therefore, modularity of developmental mechanisms is a major factor for evolvability, the potential to produce beneficial variation from random genetic change. Understanding how modularity evolves in gene regulatory networks, that create the distinct gene activity patterns that characterize different parts of an organism, is key to developmental and evolutionary biology. One hypothesis for the evolution of modules suggests that interactions between some sets of genes become maladaptive when selection favours additional gene activity patterns. The removal of such interactions by selection would result in the formation of modules. A second hypothesis suggests that modularity evolves in response to sparseness, the scarcity of interactions within a system. Here I simulate the evolution of gene regulatory networks and analyse diverse experimentally sustained networks to study the relationship between sparseness and modularity. My results suggest that sparseness alone is neither sufficient nor necessary to explain modularity in gene regulatory networks. However, sparseness amplifies the effects of forms of selection that, like selection for additional gene activity patterns, already produce an increase in modularity. That evolution of new gene activity patterns is frequent across evolution also supports that it is a major factor in the evolution of modularity. That sparseness is widespread across gene regulatory networks indicates that it may have facilitated the evolution of modules in a wide variety of cases. PMID:29775459

On the role of sparseness in the evolution of modularity in gene regulatory networks.

PubMed

Espinosa-Soto, Carlos

2018-05-01

Modularity is a widespread property in biological systems. It implies that interactions occur mainly within groups of system elements. A modular arrangement facilitates adjustment of one module without perturbing the rest of the system. Therefore, modularity of developmental mechanisms is a major factor for evolvability, the potential to produce beneficial variation from random genetic change. Understanding how modularity evolves in gene regulatory networks, that create the distinct gene activity patterns that characterize different parts of an organism, is key to developmental and evolutionary biology. One hypothesis for the evolution of modules suggests that interactions between some sets of genes become maladaptive when selection favours additional gene activity patterns. The removal of such interactions by selection would result in the formation of modules. A second hypothesis suggests that modularity evolves in response to sparseness, the scarcity of interactions within a system. Here I simulate the evolution of gene regulatory networks and analyse diverse experimentally sustained networks to study the relationship between sparseness and modularity. My results suggest that sparseness alone is neither sufficient nor necessary to explain modularity in gene regulatory networks. However, sparseness amplifies the effects of forms of selection that, like selection for additional gene activity patterns, already produce an increase in modularity. That evolution of new gene activity patterns is frequent across evolution also supports that it is a major factor in the evolution of modularity. That sparseness is widespread across gene regulatory networks indicates that it may have facilitated the evolution of modules in a wide variety of cases.