ABSTRACT
Objective: Sarcopenia is a common complication of COPD associated with an age-related reduction in skeletal muscle mass associated with decreased muscle strength and / or reduced mobility. The incidence of sarcopenia in patients with COPD is twice that of non-COPD patients and is associated with poor prognosis, this study aimed to investigate the influencing factors of sarcopenia in COPD patients. Methods: Selected studies from PubMed, Embase, Web of Science, Cochrane Library, Wanfang, Wanfang, CNKI, CBM, and Wanfang databases as of November 12023. Patients aged 18 were selected; data were then independently extracted by two reviewers using a standard data collection form. Results: In total, 17 articles reporting on 5408 patients were included. Age (OR = 1.083; 95% CI, 1.024-1.145), ALB (OR = 0.752; 95% CI, 0.724-0.780), BMI(OR = 0.701; 95% CI, 0.586-0.838), smoking (OR = 1.859; 95% CI, 1.037-3.334), diabetes (OR = 1.361; 95% CI, 1.095-1.692), qi deficiency (OR = 9.883; 95% CI, 2.052, 47.593), GOLD C (OR =2.232; 95% CI, 1.866, 2.670) and GOLD D (OR = 2.195; 95% CI, 1.826-2.637) were factors affecting muscle loss in COPD patients. Conclusion: Sarcopenia is more prevalent in patients with COPD. Age, body mass index, smoking, diabetes mellitus, qi deficiency, ALB, and GOLD grade were the contributing factors for sarcopenia in patients with chronic obstructive pulmonary disease. In the future, medical staff should not only pay attention to the early screening of sarcopenia in high-risk groups, but also provide relevant prevention information.
Subject(s)
Pulmonary Disease, Chronic Obstructive , Sarcopenia , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Age Factors , Chi-Square Distribution , Lung/physiopathology , Muscle Strength , Muscle, Skeletal/physiopathology , Odds Ratio , Prognosis , Pulmonary Disease, Chronic Obstructive/epidemiology , Pulmonary Disease, Chronic Obstructive/physiopathology , Pulmonary Disease, Chronic Obstructive/diagnosis , Pulmonary Disease, Chronic Obstructive/complications , Risk Assessment , Risk Factors , Sarcopenia/epidemiology , Sarcopenia/physiopathology , Sarcopenia/diagnosisABSTRACT
In this paper, an optically transparent and wideband absorber/reflector with switchable states and tunable frequency spectrum is presented. The proposed structure consists of a Polydimethylsiloxane (PDMS) layer with microchannel structures and an Indium Tin Oxide (ITO) layer as the metal panel. The switching function is implemented by controlling the injection and discharge of pure water, and the switchable frequency band of the absorbing and reflecting states ranges from 7.9 to 34.4 GHz with a fractional bandwidth of 125.2%. The tunable properties are achieved by changing the concentration of the injected saline water. In addition, the distributions of the electric field, the magnetic field and the power loss density are used to further understand the physical mechanism of the structure. Moreover, it also performs well under different polarizations and incident angles. For validation, a transparent and wideband absorber/reflector is fabricated and tested, and the simulated and measured results are consistent with each other.
ABSTRACT
An improved dual-polarized multifunctional switchable absorber/reflector with both wideband absorbing and wideband reflecting characteristics is presented in this paper. The proposed structure consists of three parts including a top-layer active frequency selective surface (AFSS) structure, a bottom-layer metal sheet and an air spacer in between. The polarization stability is satisfied by deploying the super-element topology, which contains four similar unitary elements arranged in a 2 × 2 matrix form. The PIN diode is employed as a RF switch in the AFSS structure for the purpose of switching. The bias networks responsible for different polarizations are intentionally separated through via holes. Multifunctional properties with four different operating states can be attained by controlling horizontally- and vertically-loaded PIN diodes independently. In addition, the biggest advantage of the proposed structure lies in its wideband features at both absorbing and reflecting states for different polarizations and incident angles. Finally, a prototype of the design is fabricated and measured to verify the simulation, and a good agreement between the simulated and observational results can be achieved under normal incidence as well as oblique incidence.
