Evidence for exercise training in autonomic function modulation in patients with chronic obstructive pulmonary disease (COPD) : a systematic review

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Autonomic function in subjects with severe COPD

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Effect of respiratory rehabilitation techniques on the autonomic function in patients with chronic obstructive pulmonary disease : a systematic review

Patients with chronic obstructive pulmonary disease (COPD) show several extrapulmonary abnormalities such as impairment in the autonomic function (AF). Similarly, the use of respiratory training techniques such as controlled breathing techniques, noninvasive mechanical ventilation (NIMV), and oxygen supplementation for AF modulation in patients with COPD is popular in existing literature. However, the evidence to support their use is nonexistent. A systematic search of studies reporting on the effect of controlled breathing techniques, NIMV, and/or oxygen supplementation techniques on AF outcome parameters was conducted in three online databases: PubMed, Embase, and Web of Science. Following the Preferred Reporting Items for Systematic reviews and Meta-Analyses statement, relevant studies were retained and qualitatively analyzed for evidence synthesis. The methodological quality in these studies was evaluated using the evidence based guideline development (EBRO) checklists per designs provided by the Dutch Cochrane Centre. Eighteen studies met the inclusion criteria of the review and were included and discussed. The evidence synthesis revealed that a strong and moderate level evidence supported oxygen supplementation and slow breathing techniques, respectively, in significantly enhancing the baroreceptor sensitivity (BRS) values in patients with COPD. The effect of the examined techniques on the heart rate variability and muscle sympathetic nerve activity was of a limited or inconsistent evidence. The findings from this review suggest that oxygen supplementation and controlled breathing techniques have profound positive influence on the BRS in patients with COPD. However, it is not fully clear whether these influence translates to any therapeutic benefit on the general AF of patients with COPD in the long term

Evidence for autonomic function and its influencing factors in subjects with COPD: a systematic review

Cardiovascular autonomic neuropathy is one of the factors implicated in the high morbidity and mortality rate in patients with COPD. Thus, several studies and nonsystematic reviews have increasingly reported autonomic function impairment in these subjects. For a better understanding, this systematic review was performed to evaluate not only the evidence for autonomic function impairment, but also factors influencing it. The results of the studies reviewed showed a strong level of evidence to support the impairment of heart rate variability in the time domain. A similar evidence level was also found to support impairment in baroreceptor sensitivity and muscle sympathetic nerve activity. Furthermore, this review identified physical activity level, muscle function, and circadian rhythm as the major influencing factors (strong evidence) of autonomic function in subjects with COPD. However, no definite conclusion could be reached for factors such as dyspnea, anxiety, body composition, pulmonary function, age, breathing frequency, ventilatory effort, quality of life, and disease severity due to limited, conflicting, or lack of existing evidence. The results of this review highlight relevant clinical messages for clinicians and other health-care providers regarding the role autonomic function can play as an important physiological marker for prognostication and stratification. Hence, autonomic function outcomes should be identified and considered during management of patients with COPD. Moreover, this review can serve as basis for future research aimed at assessing the interventions for autonomic function abnormalities in these patients

Advances in delamination modeling of metal/polymer systems: continuum aspects

Adhesion and delamination have been pervasive problems hampering the performance and reliability of micro-and nano-electronic devices. In order to understand, predict, and ultimately prevent interface failure in electronic devices, development of accurate, robust, and efficient delamination testing and prediction methods is crucial. Adhesion is essentially a multi-scale phenomenon: at the smallest scale possible, it is defined by the thermodynamic work of adhesion. At larger scales, additional dissipative mechanisms may be active which results in enhanced adhesion at the macroscopic scale and are the main cause for the mode angle dependency of the interface toughness. Undoubtedly, the macroscopic adhesion properties are a complex function of all dissipation mechanisms across the scales. Thorough understanding of the significance of each of these dissipative mechanisms is of utmost importance in order to establish physically correct, unambiguous values of the adhesion properties, which can only be achieved by proper multi-scale techniques. The topic “Advances in Delamination Modeling” has been split into two separate chapters: this chapter discusses the continuum aspects of delamination, while the next chapter deals with the atomistic aspects of interface separation. The chapter starts with a concise overview of the theory on interface fracture mechanics, followed by five applications: (1) buckling-driven delamination in flexible displays, in which a combined numerical-experimental approach is used to establish macroscopic adhesion properties, as a function of mode angle; (2) a multi-scale method to identify the relevant dissipative mechanisms in fibrillating metal/elastomer interfaces that are encountered in stretchable electronics; (3) analysis and prediction of a particular microscale dissipative mechanism at patterned (roughened) interfaces, as a result of the competition between adhesive and cohesive failures; (4) advanced model parameter identification by integrated digital image correlation which essentially eliminates the need for calculating displacements from images prior to parameter identification; and (5) the modeling of the sintering behavior of Ag particles in a thermal interconnect material