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61.
Comodulation masking release (CMR) has been attributed to auditory processing within one auditory channel (within-channel cues) and/or across several auditory channels (across-channel cues). The present flanking-band (FB) experiment—using a 25-Hz-wide on-frequency noise masker (OFM) centered at the signal frequency of 10 kHz and a single 25-Hz-wide noise FB—was designed to separate the amount of CMR due to within- and across-channel cues and to investigate the role of temporal cues on the size of within-channel CMR. The results demonstrated within-channel CMR in the Naval Medical Research Institute mouse, while no unambiguous evidence could be found for CMR occurring due to across-channel processing (i.e., “true CMR”). The amount of within-channel CMR was dependent on the frequency separation between the FB and the OFM. CMR increased from 4 to 6 dB for a frequency separation of 1 kHz to 18 dB for a frequency separation of 100 Hz. The large increase for a frequency separation of 100 Hz is likely to be due to the exploitation of changes in the temporal pattern of the stimulus upon the addition of the signal. Temporal interaction between both masker bands results in modulations with a large depth at a modulation frequency equal to the beating rate. Adding a signal to the maskers reduces the depth of the modulation. The auditory system of mice might be able to use the change in modulation depth at a beating frequency of 100 Hz as a cue for signal detection, while being unable to detect changes in modulation depth at high modulation frequencies. These results are consistent with other experiments and model predictions for CMR in humans which suggested that the main contribution to the CMR effect stems from processing of within-channel cues.  相似文献   
62.
ObjectiveTo investigate the short-term effects of dry needling (DN) on physical function, pain, and hip muscle strength in patients with hip osteoarthritis (OA).DesignA double-blind, placebo-control, randomized controlled trial.SettingPrivate practice physiotherapy clinic.ParticipantsPatients with unilateral hip OA (N=45) were randomly allocated to a DN group, sham DN group, or control group.InterventionsPatients in the DN and sham groups received 3 treatment sessions. Three active myofascial trigger points (MTrPs) were treated in each session with DN or a sham needle procedure. The treatment was applied in active MTrPs of the iliopsoas, rectus femoris, tensor fasciae latae, and gluteus minimus muscles.Main Outcome MeasuresPhysical function was assessed with the Western Ontario and McMaster Universities (WOMAC) physical function subscale, the timed Up and Go test, and the 40-meter self-paced walk test. Intensity of hip pain related to physical function was evaluated using the visual analog scale and WOMAC pain subscale. The maximal isometric force of hip muscles was recorded with a handheld dynamometer.ResultsSignificant group by time interactions were shown for physical function, pain, and hip muscle force variables. Post hoc tests revealed a significant reduction in hip pain and significant improvements in physical function and hip muscle strength in the DN group compared with the sham and control groups. The DN group showed within- and between-groups large effect sizes (d>0.8).ConclusionsDN therapy in active MTrPs of the hip muscles reduced pain and improved hip muscle strength and physical function in patients with hip OA. DN in active MTrPs of the hip muscles should be considered for the management of hip OA.  相似文献   
63.
Rationale: Prepulse inhibition (PPI) of the startle reflex is a measure of sensorimotor gating, that is the processing of the startle stimulus (S2) is inhibited by the interfering processing of a closely preceding prepulse (S1). It has been demonstrated that PPI is disrupted in a variety of mental disorders and that several neurotransmitter systems, including dopamine, participate in the modulation of sensorimotor gating. Previous studies have also shown that a task-relevant S1 enhances PPI in healthy subjects but not in schizophrenic patients. These findings indicate an influence of attentional processes on sensorimotor gating and an impairment of this modulation in schizophrenia. Objective: Assuming a dopamine-mediated suppression of S1 processing as a mechanism of resource management and selective attention, which might be impaired in certain mental disorders, the present study investigated the effects of the indirect dopaminergic agonist d-amphetamine on prepulse-altered S2 discrimination and event related potentials (ERPs). Methods: Twelve healthy volunteers were tested in a double-blind, placebo-controlled experimental design. Here, S2 is the target in a difficult Go/NoGo auditory discrimination task. Results: Confirming our previous results, S2 processing is ”accentuated” by a weak acoustic prepulse in healthy subjects, thus leading to a lower rate of errors of omission but also to more false alarms (i.e. a liberal response bias). This performance change correlated with a prepulse-induced increase in the amplitude of the P3 ERP towards non-targets (”prepulse-induced non-target positivity”; PINTP). In addition, the results of the present study show that under prepulse conditions amphetamine disrupts ”S2 accentuation” associated with a dose-related reduction of the P2 component of the S1 response and a plasma level related reduction of PINTP. Conclusions: These data suggest an involuntary attentional shift towards S1 processing with increasing dopamine-release similar to that observed in patients with schizophrenia or OCD. It is concluded that sensory gating alters selective attention via dopaminergic modulation. Received: 30 March 1998 / Final version: 10 February 1999  相似文献   
64.
ObjectiveTo investigate the prevalence of comorbidities and their effect on physical function, quality of life (QOL), and pain, in patients with end-stage knee osteoarthritis (OA).DesignA cross-sectional study.SettingA rehabilitation facility at university hospital.ParticipantsPatients (N=577; 503 women and 74 men) diagnosed with end-stage knee OA between October 2013 and June 2018.InterventionNot applicable.Main Outcome MeasuresComorbidities were as follows: osteoporosis, presarcopenia, degenerative spine disease, diabetes, and hypertension. All patients completed the following performance-based physical function tests: stair-climbing test (SCT), 6-minute walk test (6MWT), timed Up and Go (TUG) test, and gait analysis. Self-reported physical function and pain were measured using Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) and a visual analog scale (VAS), respectively, and self-reported QOL was measured using EuroQoL 5 dimensions (EQ-5D) questionnaire.ResultsUnivariate analyses revealed that patients with osteoporosis had significantly higher scores in SCT ascent, SCT descent, TUG, WOMAC pain tests, and lower scores in 6MWT, gait speed, and cadence tests than those without osteoporosis. Patients with presarcopenia recorded higher scores in SCT ascent, TUG, EQ-5D, and lower scores in 6MWT and gait speed tests than those without presarcopenia. Patients with degenerative spine disease showed higher scores in WOMAC pain and lower scores in gait speeds than those without degenerative spine disease. Patients with diabetes showed higher scores in SCT ascent than those without diabetes, and patients with hypertension showed lower scores in 6MWT than those without hypertension. After adjusting age, sex, and body mass index, SCT descent retained significant association with osteoporosis, SCT ascent showed independent association with presarcopenia and diabetes, and WOMAC pain revealed significant association with degenerative spine disease.ConclusionThe results confirm associations between comorbidities, performance-based and self-reported physical functions, and QOL in patients with end-stage knee OA.  相似文献   
65.
Skeletal Aging     
Aging represents the single greatest risk factor for chronic diseases, including osteoporosis, a skeletal fragility syndrome that increases fracture risk. Optimizing bone strength throughout life reduces fracture risk. Factors critical for bone strength include nutrition, physical activity, and vitamin D status, whereas unhealthy lifestyles, illnesses, and certain medications (eg, glucocorticoids) are detrimental. Hormonal status is another important determinant of skeletal health, with sex steroid concentrations, particularly estrogen, having major effects on bone remodeling. Aging exacerbates bone loss in both sexes and results in imbalanced bone resorption relative to formation; it is associated with increased marrow adiposity, osteoblast/osteocyte apoptosis, and accumulation of senescent cells. The mechanisms underlying skeletal aging are as diverse as the factors that determine the strength (and thus fragility) of bone. This review updates our current understanding of the epidemiology, pathophysiology, and treatment of osteoporosis and provides an overview of the underlying hallmark mechanisms that drive skeletal aging.  相似文献   
66.
67.

Background

The authors conducted a study to compare 2-dimensional (2D) lateral cephalometric radiography (LCR), 2D cone-beam computer tomographic (CBCT)–generated cephalogram and 3-dimensional (3D) CBCT for assessing cephalometric measurements.

Methods

The authors took 2D LCR, 2D CBCT-generated cephalogram, and 3D CBCT images involving 60 participants. They obtained 11 angular and 11 linear measurements for all images. They used 1-way analysis of variance and the Fisher least significant difference test for statistical comparisons. The authors used Pearson correlation and Pearson χ2 test to assess the relationship of these imaging modalities for vertical cephalometric analyses.

Results

Significant differences existed between the 2D cephalograms (LCR and CBCT-generated cephalogram) and the 3D CBCT in 2 angular measurements (maxillary first incisor-nasion (N) point A [A] and mandibular first incisor-N point B (B) (P = .027 and P < .001, respectively) and 5 linear measurements (N menton[Me]/sella gonion [Go], condylion [Co]A, Co gnathion, Go-Me and anterior nasal spine-posterior nasal spine) (P < .004). These measurement values with significant differences were generally greater (approximately 5° for angular measurements and 10 millimeters for linear measurements) on the 3D CBCT scans than on the 2D cephalograms. No significant difference was found between the 2 2D cephalograms (P > .164). No significant difference was found among the 3 imaging modalities for the vertical cephalometric analyses (P > .466).

Conclusions

Significant differences existed between the 2D cephalograms (LCR and CBCT-generated cephalogram) and the 3D CBCT scans in 2 angular and 5 linear measurements. The 2 2D cephalograms were similar for cephalometric measurements. The 3 imaging modalities had no significant difference for the vertical cephalometric analyses. CBCT might not add value for every orthodontic situation.

Practical Implications

These results find the values of cephalometric measurements on 3D CBCT scans may be greater than on the conventional LCR for some parameters. The 2D CBCT-generated cephalogram could be an alternative to the conventional LCR for patients whose large-field-of-view CBCT images are already available.  相似文献   
68.

Objective

To evaluate the effect of the Assistive Device Selection, Training and Education Program (ADSTEP) on falls and walking and sitting activity in people with multiple sclerosis (PwMS).

Design

Randomized controlled trial.

Setting

Veterans affairs medical center.

Participants

PwMS (N=40) using a walking aid at baseline who had fallen in the previous year.

Interventions

Participants were randomly assigned to ADSTEP or control. ADSTEP had 6 weekly, 40-minute, 1-on-1 sessions with a physical therapist, starting with walking aid selection and fitting, followed by task-oriented progressive gait training. Control was usual medical care with the option of ADSTEP after the study.

Main Outcome Measures

The following were assessed at baseline, intervention completion, and 3 months later: falls, timed Up and Go, timed 25-foot walk, 2-minute walk, Four Square Step Test, International Physical Activity Questionnaire, Quebec User Evaluation of Satisfaction with Assistive Technologies, Multiple Sclerosis Walking Scale-12, Activities-Specific Balance Confidence Scale, and Multiple Sclerosis Impact Scale-29. Effect on these outcomes was estimated by a 2-by-2 repeated measures general linear model.

Results

Fewer ADSTEP than control participants fell (χ2=3.96, P<.05. number needed to treat =3.3). Time spent sitting changed significantly differently with ADSTEP than with control from baseline to intervention completion (F=11.16, P=.002. ADSTEP: reduced 87.00±194.89min/d; control: increased 103.50±142.21min/d; d=0.88) and to 3-month follow-up (F=9.25, P=.004. ADSTEP: reduced 75.79±171.57min/d; control: increased 84.50±149.23min/d; d=0.79). ADSTEP yielded a moderate effect on time spent walking compared to control at 3-month follow-up (P>.05. ADSTEP 117.53±148.40min/d; control 46.43±58.55min/d; d=0.63).

Conclusions

ADSTEP prevents falls, reduces sitting, and may increase walking in PwMS.  相似文献   
69.

Objectives

To estimate the treatment effects of exercise and/or gait training interventions on dual–task walking in people with stroke. The secondary objective was to conduct subgroup analyses to compare the treatment effects of interventions involving dual–task training to those without any dual–task training.

Data Sources

A systematic search of the literature was conducted in 6 databases (PubMed, CINAHL, EMBASE, Web of Science, Cochrane Central Register of Controlled Trials, and Physiotherapy Evidence Database) up to July 18, 2017.

Study Selection

Randomized controlled trials (RCTs), nonrandomized controlled trials, or uncontrolled studies involving individuals with stroke and examining the effects of exercise and/or gait training interventions on dual–task gait speed.

Data Extraction

We extracted data on participant characteristics, intervention duration, frequency, and type; pre and post gait speed and secondary nongait task performance for single and dual–task conditions, types of tasks used for dual–task assessment and dual–task prioritization instructions.

Data Synthesis

Of 313 articles identified, 7 studies involving 12 independent treatment arms (n=124) met the inclusion criteria. There was a significant pre–post intervention increase in dual–task gait speed (MD: 0.03m/s, 95% CI: 0.01, 0.06) and single–task gait speed (MD: 0.06m/s, 95% CI: 0.03, 0.09). Dual–task training tended to have a larger effect on dual–task gait speed than interventions without dual–task training. Between–group analysis of three RCTs found evidence of superiority of dual–task gait training over single–task gait training for improving dual–task gait speed (MD: 0.08m/s, 95% CI: 0.02, 0.14).

Conclusions

Exercise and gait training interventions, especially those involving dual–task practice, may improve dual–task gait speed after stroke, but the clinical significance is unclear. Current effect size estimates lack precision due to small sample sizes of existing studies.  相似文献   
70.
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