The Relationship between Exertional Desaturation and Pulmonary Function, Exercise Capacity, or Medical Costs in Chronic Obstructive Pulmonary Disease Patients.

Background and Objectives: Exertional desaturation (ED) is common and is associated with poorer clinical outcomes in chronic obstructive pulmonary disease (COPD). The age, dyspnea, airflow obstruction (ADO) and body mass index, airflow obstruction, dyspnea, and exercise (BODE) indexes are used to predict the prognosis of COPD patients. This study aimed to investigate the relationship between these indexes, pulmonary function, medical costs, and ED in COPD patients. Materials and Methods: Data were collected from the electronic database of the Kaohsiung Chang Gung Memorial Hospital. This retrospective study included 396 patients categorized as either ED (n = 231) or non-ED (n = 165). Variables (including age, smoking history, body mass index (BMI), pulmonary function test, maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP), six minutes walking test distance (6MWD), SpO2, COPD Assessment Test (CAT) score, ADO index, BODE index, Charlson comorbidity index (CCI), and medical costs) were compared between the two groups, and their correlations were assessed. ED was defined as SpO2 less than 90% or SpO2 decrease of more than 4% compared to baseline levels during 6MWT. Results: A significant statistical difference was found regarding a lower score of the ADO index and the BODE index (both p < 0.001), better pulmonary function (forced expiratory volume in the first second (FEV1), p < 0.001; FEV1/ forced vital capacity (FVC), p < 0.001; diffusion capacity of the lung for carbon monoxide (DLCO), p < 0.001), and higher minimal oxygen saturation (p < 0.001) in non-ED COPD patients. No difference was found in the distance of the 6MWT (p = 0.825) and respiratory muscle strength (MIP; MEP, p = 0.86; 0.751). However, the adjusted multivariate logistic regression analysis showed that only SpO2 (minimal) had a significant difference between of the ED and non-ED group (p < 0.001). There was either no difference in the medical expenses between ED and non-ED COPD patients. Conclusions: SpO2 (minimal) during the 6MWT is the independent factor for ED. ED is related to BODE and ADO indices, but is not related to medical expense.

Comparison of BODE and ADO Indices in Predicting COPD-Related Medical Costs.

Background and Objectives:The ADO (age, dyspnea, and airflow obstruction) and BODE (body mass index, airflow obstruction, dyspnea, and exercise capacity) indices are often used to evaluate the prognoses for chronic obstructive pulmonary disease(COPD); however, an index suitable for predicting medical costs has yet to be developed. Materials and Methods: We investigated the BODE and ADO indices to predict medical costs and compare their predictive power. A total of 396 patients with COPD were retrospectively enrolled. Results: For hospitalization frequencies, BODE was R2 = 0.093 (p < 0.001), and ADO was R2 = 0.065 (p < 0.001); for hospitalization days, BODE was R2 = 0.128 (p < 0.001), and ADO was R2 = 0.071 (p < 0.001); for hospitalization expenses, BODE was R2 = 0.020 (p = 0.047), and ADO was R2 = 0.012 (p = 0.179). BODE and ADO did not differ significantly in the numbers of outpatient visits (BODE, R2 = 0.012, p = 0.179; ADO, R2 = 0.017, p = 0.082); outpatient medical expenses (BODE, R2 = 0.012, p = 0.208; ADO, R2 = 0.008, p = 0.364); and total medical costs (BODE, R2 = 0.018, p = 0.072; ADO, R2 = 0.016, p = 0.098). In conclusion, BODE and ADO indices were correlated with hospitalization frequency and hospitalization days. However, the BODE index exhibits slightly better predictive accuracy than the ADO index in these items.

An Interleaved Segmented Spectrum Analysis: A Measurement Technique for System Frequency Response and Fault Detection.

A frequency spectrum segmentation methodology is proposed to extract the frequency response of circuits and systems with high resolution and low distortion over a wide frequency range. A high resolution is achieved by implementing a modified Dirichlet function (MDF) configured for multi-tone excitation signals. Low distortion is attained by limiting or avoiding spectral leakage and interference into the frequency spectrum of interest. The use of a window function allowed for further reduction in distortion by suppressing system-induced oscillations that can cause severe interference while acquiring signals. This proposed segmentation methodology with the MDF generates an interleaved frequency spectrum segment that can be used to measure the frequency response of the system and can be represented in a Bode and Nyquist plot. The ability to simulate and measure the frequency response of the circuit and system without expensive network analyzers provides good stability coverage for reliable fault detection and failure avoidance. The proposed methodology is validated with both simulation and hardware.

Photocatalytic removal of toxic dyes, liquorice and tetracycline wastewaters by a mesoporous photocatalyst under irradiation of different lamps and sunlight.

Simple recyclable K5CoW12O40/TiO2 was synthesized and used to remove methyl orange, rhodamine B, direct red 16 and crystal violet toxic organic dyes, liquorice industrial wastewater and tetracycline (TC) as an antibiotic. Photoactivity of the catalyst was checked out under irradiation of various lamps (such as 18 W fluorescent, 300 W Xenon, LED and IR lamps). The best efficiency was obtained by fluorescent lamp at catalyst loading of 3 g/L, initial pH of 5, initial dye concentration of 5 ppm, complete degradation was achieved after 30 min contact time. Mechanistic investigation showed that·O2 radicals and h+ are majorly responsible for photodegradation in this process. Electrochemical investigation, Nyquist, Bode, Mott-Schottky, Tauc plots and photoluminescence proved that using this photocatalyst delay the electron-hole recombination, increase the lifetime of excited electron, extend light absorption to visible region and improve the light absorption capacity. This photocatalyst work well under winter sunlight. Also 97% and 84% dye removal was obtained for liquorice with 300 and 1000 COD at optimal condition. This catalyst showed similar activity for TC wastewater. Photocatalyst was characterized by FE-SEM, EDX, AFM, FT-IR, XRD, PL, DRS, EIS, BJH and BET.

The Electrochemical Stability of Starch Carbon as an Important Property in the Construction of a Lithium-Ion Cell.

This paper shows use of starch-based carbon (CSC) and graphene as the anode electrode for lithium-ion cell. To describe electrochemical stability of the half-cell system and kinetic parameters of charging process in different temperatures, electrochemical impedance spectroscopy (EIS) measurement was adopted. It has been shown that smaller resistances are observed for CSC. Additionally, Bode plots show high electrochemical stability at higher temperatures. The activation energy for the SEI (solid-electrolyte interface) layer, charge transfer, and electrolyte were in the ranges of 24.06-25.33, 68.18-118.55, and 13.84-15.22 kJ mol-1, respectively. Moreover, the activation energy of most processes is smaller for CSC, which means that this electrode could serve as an eco-friendly biodegradable lithium-ion cell element.

Daily physical activity and related risk factors in COPD.

BACKGROUND: Factors associated with reduced daily physical activity (DPA) in patients with COPD are still controversial. Physical inactivity in COPD increases risk of cardiovascular disease, frequent exacerbations, reduced health status, and increased symptoms. We hypothesised that reduced DPA in patients with COPD is independent of traditional risk factors including age and spirometry. METHODS: In this cross-sectional study, DPA (over 7 days) was assessed on 88 community stable patients with COPD and 40 controls free from cardiorespiratory disease. Spirometry, body composition, number of exacerbations, handgrip strength (HGS), modified Medical Research Council (mMRC), arterial stiffness, 6-min walking distance (6MWD) and BODE index were also determined. Frequent exacerbation was defined as ≥2 and non-frequent exacerbation < 2. RESULTS: Patients with COPD had reduced DPA and exercise capacity compared with controls similar in age, BMI and gender, p < 0.001. Frequent exacerbators had less DPA than infrequent exacerbators and both less than controls, p < 0.001. Patients with higher BODE index were less active than those with lower index. Time spent on moderate activity was related to cardiovascular risk factors including arterial stiffness. The DPA in patients was independent of age, gender, spirometry, body composition and HGS, p > 0.05. The level of breathlessness was superior to lung function in predicting the level of DPA. CONCLUSION: The level of DPA in COPD was independent of traditional risk factors. Breathlessness score is a better predictor of the DPA than lung function and handgrip strength.

It's more than low BMI: prevalence of cachexia and associated mortality in COPD.

BACKGROUND: Cachexia is associated with increased mortality risk among chronic obstructive pulmonary disease (COPD) patients. However, low body mass index (BMI) as opposed to cachexia is often used, particularly when calculating the BODE (BMI, Obstruction, Dyspnea and Exercise) index. For this reason, we examined mortality using a consensus definition and a weight-loss definition of cachexia among COPD cases and compared two new COPD severity indices with BODE. METHODS: In the current report, the consensus definition for cachexia incorporated weight-loss > 5% in 12-months or low BMI in addition to 3/5 of decreased muscle strength, fatigue, anorexia, low FFMI and inflammation. The weight-loss definition incorporated weight-loss > 5% or weight-loss > 2% (if low BMI) in 12-months. The low BMI component in BODE was replaced with the consensus definition to create the CODE (Consensus cachexia, Obstruction, Dyspnea and Exercise) index and the weight-loss definition to create the WODE (Weight loss, Obstruction, Dyspnea and Exercise) index. Mortality was assessed using Kaplan-Meier survival and Cox Regression. Performance of models was compared using C-statistics. RESULTS: Among 1483 COPD cases, the prevalences of cachexia by the consensus and weight-loss definitions were 4.7 and 10.4%, respectively. Cachectic patients had a greater than three-fold increased mortality by either the consensus or the weight-loss definition of cachexia independent of BMI and lung function. The CODE index predicted mortality slightly more accurately than the BODE and WODE indices. CONCLUSIONS: Cachexia is associated with increased mortality among COPD patients. Monitoring cachexia using weight-loss criteria is relatively simple and predictive of mortality among COPD cases who may be missed if only low BMI is used.

Bone mineral density and vertebral fractures and their relationship with pulmonary dysfunction in patients with chronic obstructive pulmonary disease.

To evaluate bone mineral density (BMD) and morphometric vertebral fractures (MVF) in chronic obstructive pulmonary disease (COPD) patients in comparison with two control groups. BMD was lower in the disease group (DG) and was associated with the worst disease severity and prognosis. The prevalence of MVF was high and greater in the DG than in the control groups. INTRODUCTION: Chronic obstructive pulmonary disease (COPD) is associated with osteoporosis and vertebral fractures. It is still unclear whether the presence of fractures and changes in bone mineral density (BMD) are associated with disease severity and prognosis. The aim of this study was to evaluate BMD and morphometric vertebral fractures (MVF) in COPD patients in comparison with two control groups and to correlate these parameters with indices of COPD severity (VEF1 and GOLD) and prognosis (BODE). METHODS: This was a cross-sectional study in COPD patients (disease group, DG) who underwent BMD and vertebral fracture assessment (VFA). Two control groups were used: smokers without COPD (smoker group, SG) and healthy never-smoker individuals (never-smoker group, NSG). RESULTS: The DG comprised 121 patients (65 women, mean age 67.9 ± 8.6 years). Altered BMD was observed in 88.4% of the patients in the DG, which was more prevalent when compared with the control groups (p < 0.001). The BMD values were lower in the DG than in the control groups (p < 0.05). BMD was associated with the worst disease severity and prognosis (p < 0.05). The prevalence of MVF was high (57.8%) and greater than that in the SG (23.8%) and the NSG (14.8%; p < 0.001). The prevalence of fractures was not associated with disease severity and prognosis. CONCLUSIONS: COPD patients have a higher prevalence of MVF and low BMD, and the latter was associated with the severity and poor prognosis of the disease.

Evaluation of Left Ventricular Function and its Relationship With Multidimensional Grading System (BODE Index) in Patients With COPD.

Cardiovascular disease (CVD) is one of the main causes of morbidity and mortality in chronic obstructive pulmonary disease (COPD) patients however data regarding left ventricle (LV) function in COPD is limited. We, in this study, aimed to evaluate the LV systolic function and its relation to BODE index in COPD patients with the utility of two-dimensional speckle tracking echocardiography (2D-STE). The study involved 125 COPD patients and 30 control subjects. All patients underwent 2D-echocardiography, pulmonary function tests and -minute walk tests. The patients were divided into four quartiles according to BODE index score. COPD patients had lower mitral annulus systolic velocity (Sm), average global longitudinal strain (GLS), average global longitudinal strain rate systolic (GLSRs), average GLSR early diastolic (GLSRe), average GLSR late diastolic (GLSRa), tricuspid annular plane systolic excursion (TAPSE) and peak systolic myocardial velocity (Sm-RV) (p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001 and p = 0.002 respectively) than control subjects. There were significant differences between BODE index quartiles in terms of Sm, average GLS and average GLSRs. Patients were divided into two groups according to median value of GLS (> -18.6 and ≤ -18.6). BODE index quartiles were found to be independent predictors of decreased GLS in multivariate logistic regression analysis (p = 0.030). Increased BODE index was associated with impaired LV mechanics in patients with COPD.

BODE index or geriatric multidimensional assessment for the prediction of very-long-term mortality in elderly patients with chronic obstructive pulmonary disease? a prospective cohort study.

BACKGROUND: a multidimensional approach-the BODE index-has been proposed for prognostic purposes in chronic obstructive pulmonary disease (COPD) and theoretically seems to be well suited for elderly people, but there is a lack of data in this population, especially with respect to long-term survival. The objective of this study is to evaluate whether the BODE index can predict both long (5 years) and very-long (10 and 15 years)-term mortality in an unselected population of elderly people with COPD better than a set of variables commonly taken into account in a geriatric multidimensional assessment (MDA). METHODS: : this was a multicentre, prospective, population study. We used data from the SaRA study, which included 563 elderly people with COPD whose vital status was ascertained for up to 15 years after enrolment. The discriminative capacity of the BODE index in predicting mortality was derived from Cox proportional hazard models including the components of the BODE index and compared with that of an alternative model based on MDA variables: age, gender, physical disability, cognitive function and mood status. RESULTS: : at 5 years, the HRs for mortality were 1.04 (95% CI: 0.60-1.79), 1.88 (1.10-3.22) and 3.55 (2.15-5.86) for quartiles 2-4, respectively, compared with quartile 1 of the BODE index. The corresponding figures for 10-year mortality were 1.50 (1.01-2.24), 2.11 (1.39-3.20) and 3.903 (2.62-5.82), and for 15-year mortality were 1.68 (1.19-2.36), 2.08 (1.44-3.01) and 3.78 (2.64-5.41). Similar results were obtained using variables included in the usual MDA. CONCLUSIONS: : Both the 'classic' MDA and the BODE index are comparably associated with mortality, even at very long term, in elderly people with COPD.

Validation of the i-BODE index as a predictor of hospitalization and mortality in patients with COPD participating in pulmonary rehabilitation.

Abstract The aim of this study was to examine the value of the i-BODE index to predict hospital admission and to confirm its usefulness to predict mortality in a Danish population. The incremental shuttle walking test (ISWT) is widely used in the UK and Europe and previous work has examined the replacement of the 6MWT with the ISWT within the BODE index for predicting the prognosis of COPD (i-BODE). The 674 patients included in the analysis participated in a 7-week pulmonary rehabilitation program from 2002 to 2011. The National Health Services Central Register ascertained vital status and provided information on all hospital admissions. The mean follow-up period was 66 months (range 11-118 months). Cox proportional hazards model was used to identify factors that significantly predicted mortality and time to first hospital admission. The i-BODE index as well as body mass index, MRC dyspnea grade, and exercise capacity (ISWT) were significantly associated with all-cause mortality. The adjusted hazard ratio for death per one point increase in the i-BODE score was 1.28 (95% confidence interval 1.20 to 1.37). The i-BODE index was also a significant predictor of hospitalization, both for all causes and COPD exacerbation. Patients in the highest i-BODE quartile had a median time to first hospitalization of 17 months compared to 51 months for patients in the lowest quartile. The i-BODE index is a significant predictor of hospital admission and thus health care utilization, and also mortality.

The role of serum chloride ion in the prognosis of COPD.

BACKGROUND: As exacerbations of chronic obstructive pulmonary disease (COPD) are one of the leading causes of hospitalization and are associated with significant mortality, it is particularly important to accurately assess the risk of exacerbations in COPD. Most of the current clinical biomarkers are related to inflammation and few consider how ion levels affect COPD. Chloride ion, the second most abundant serum electrolyte, has been shown to be associated with poor prognoses in several diseases, but their relationship with COPD remains unclear. METHODS: In total, 105 patients with acute exacerbations of COPD were recruited. Data on clinical characteristics, lung function, blood count, blood biochemistry, relevant scales including the Clinical COPD Questionnaire (CCQ), BODE (BMI, airflow obstruction, dyspnea, exercise capacity) index and the St. George's Respiratory Questionnaire (SGRQ) were collected from all patients for statistical analysis. RESULT: There were significant differences in lung function indicators and disease severity in the low chloride ion subgroup compared with the high chloride ion subgroup. On multiple logistic regression analysis, chloride ion was an independent factor affecting lung function in COPD patients (OR = 0.808, 95% CI: 0.708 - 0.922, p = 0.002). The sensitivity of chloride ion in predicting COPD severity was 78%, the specificity was 63%, and the area under the curve was 0.734 (p < 0.001). Subgroup analysis showed that chloride ion was a stronger predictor in male and smoking patients. CONCLUSIONS: Chloride ion was a novel prognostic biomarker for COPD, and low levels of chloride ion were independently associated with exacerbations in COPD patients.

Feasibility of a home-designed respiratory rehabilitation program for chronic obstructive pulmonary disease.

BACKGROUND: According to international guidelines, respiratory rehabilitation (RR) for patients with chronic obstructive pulmonary disease (COPD) is a cornerstone of standard non-pharmacological treatment. AIMS: To evaluate feasibility of a home-designed RR program and analyze its medium-term impact on respiratory parameters and quality of life. METHODS: This was a prospective study involving 74 COPD patients enrolled in January 2019 and put on inhaled bronchodilator treatment associated with RR at home following a written protocol, for 16 weeks. The comparative statistical analysis highlights the difference before and after RR in terms of clinical and functional respiratory parameters as well as in terms of quality of life (assessed on the short form 36 (SF-36) questionnaire). The comparison involves RR-adherent patients versus non-adherent patients. RESULTS: Mean age was 66.7 ± 8.3 years with a median of 67 years. All patients were smokers, out of which 42 patients (57%) did not quit yet. Forty-one percent of patients were frequent exacerbators. The average COPD assessment test (CAT) score in our patients was 23. The average 6-minutes walk distance (MWD) was 304 m. The BODE index in our patients was 4.11 on average. The RR program was followed by 36 patients (48%). Thirty patients (40%) applied it at least twice a week. RR-adherent patients had an average CAT score decreasing from 23 to 14.5 (P = 0.011). Their average 6-MWD was 444.6 m by the end of the study, which would be 64.2% of the calculated theoretical value. The average FEV1 increase after RR was 283 mL. The majority (69%) of RR-adherent patients were ranked as quartile 1; BODE index ≤2. The average scores of physical, psycho-social, and general dimensions assessed on the SF-36 questionnaire improved in RR-adherent patients. CONCLUSIONS: RR is a key non-pharmacological treatment for COPD. Its interest originates from its multidisciplinary nature, hence its effectiveness in several respiratory parameters. Our study reflects the feasibility of home-designed protocols in the absence of contraindications. We highlight also the positive impact on quality of life after RR at home.

Left ventricular concentric remodeling in COPD patients: A cross-sectional observational study.

OBJECTIVE: To investigate the association between left ventricular structure and disease severity in COPD patients. METHODS: Twenty-eight COPD patients were stratified according to the disease severity, using the BODE index, into Lower (n=17) and Higher (n=11) groups, composed of patients with lower severity (BODE <5) and higher severity (BODE ≥5), respectively. Left ventricle (LV) was assessed by 2D-echocardiography. BODE index was calculated using body mass index (BMI); forced expiratory volume in the first second (FEV1, %); modified Medical Research Council (mMRC) and distance walked during 6-minute walk test (6MWD). RESULTS: Patients in the Higher group showed lower oxygen arterial saturation (p=0.02), FEV1 (p<0.01) and 6MWD (p=0.02) and higher value of relative posterior wall thickness (RWT) compared to Lower group (p=0.02). There were significant associations between LV end-systolic diameter (LVESD) and BODE index (r=-0.38, p=0.04), LV end-diastolic diameter (LVEDD) and FEV1 (r=0.44, p=0.02), LVEDD and BMI (r=0.45, p=0.02), LVESD and BMI (r=0.54, p=0.003) and interventricular septal thickness and 6MWD (r=-0.39, p=0.04). CONCLUSIONS: More severe COPD patients, BODE score ≥5, may have higher RWT, featuring a possible higher concentric remodeling of LV in this group. Besides that, a greater disease severity may be related to LV chamber size reduction.

Multidisciplinary diagnosis and treatment model based on a retrospective cohort study: Pulmonary function and prognosis quality of life in severe COPD.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a common chronic respiratory disease worsening airflow limitation. OBJECTIVE: To explore pulmonary function rehabilitation, life quality and prognosis in patients with severe COPD. METHODS: Between February 2018 and August 2021, 150 patients with severe COPD cured in our hospital were arbitrarily assigned into the control group (n= 75) and study group (n= 75). The control group received routine treatment and the research group received multidisciplinary diagnosis and treatment. The body mass index, airflow obstruction, dyspnea and exercise (BODE), pulmonary function, the number of acute attacks, 6-minute walking distance (6MWD), Borg score and life quality were compared. RESULTS: There was no remarkable difference in BODE score before treatment (P> 0.05). During the 2- and 6-month following treatment, the BODE score of the study group was lower (P< 0.05). In the study group, FEV1 percentage of the predicted value, forced expiratory volume in one second (PPO-FEV1) and the percentage of forced expiratory volume in one second/forced vital capacity (FEV1/FVC) in the first second were higher (P< 0.05). In the study group, there were fewer acute attacks (P< 0.05). After treatment, the 6MWD of the study group following 2- and 6-month treatment was higher (P< 0.05). The Borg scores of the study group at 2- and 6-months after treatment were lower (P< 0.05). There were no remarkable differences in the score of life quality before treatment (P> 0.05), however, the symptom score, activity score, influence score and total score of the study group were lower after the treatment (P< 0.05). CONCLUSION: The application of multidisciplinary diagnosis and treatment model can promote the rehabilitation of pulmonary function of patients with severe COPD, improve their prognosis, slow down the development of the disease and enhance their life quality.

Postural control and fear of falling assessment in people with chronic obstructive pulmonary disease: a systematic review of instruments, international classification of functioning, disability and health linkage, and measurement properties.

OBJECTIVES: To systematically review the instruments used to assess postural control and fear of falling in people with chronic obstructive pulmonary disease (COPD), and to synthesize and evaluate their breadth of content and measurement properties. DATA SOURCES: MEDLINE, EMBASE, Web of Science, CINAHL, CENTRAL, PsycINFO, PEDro, and OTSeeker databases searched in September 2012. STUDY SELECTION: Two independent reviewers performed the selection of articles, the ICF linking process and quality assessment. Only quantitative studies were included, irrespective of language or publication date. DATA EXTRACTION: This systematic review comprised two phases. Phase 1 aimed to identify the commonly used instruments to assess postural control and fear of falling in the COPD literature. The breadth of content of each instrument was examined based on the International Classification of Functioning, Disability and Health (ICF). In phase 2, a measurement property search filter was adopted and used in four electronic databases to retrieve properties reported in the COPD population. The COSMIN checklist was used to assess the methodological quality of each measurement property reported. DATA SYNTHESIS: Seventeen out of 401 publications were eligible in phase 1. Seventeen instruments were identified including 15 for postural control and 2 for fear of falling assessment. The Berg Balance Scale, the Short Physical Performance Battery, and the Activities-specific Balance Confidence (ABC) scale were the most frequently used instruments to assess postural control and fear of falling respectively. The ICF categories covered varied considerably among instruments. The Balance Evaluation Systems test and ABC presented the greatest breadth of content. Measurement properties reported included criterion predictive validity (4 instruments), construct validity (11 instruments) and responsiveness (1 instrument), with inconsistent findings based on 'fair' and 'poor' quality studies. CONCLUSIONS: Different instruments with heterogeneous content have been used to assess postural control and fear of falling outcomes. Standardized assessment methods and best evidence on measurement properties is required in the COPD literature.

Abnormal heart rate recovery and chronotropic incompetence on exercise in chronic obstructive pulmonary disease.

Chronotropic incompetence (CI; failure to reach the targeted heart rate (HR) on exercise) and a delayed HR recovery (HRR; ≤12 beats decline within the first minute after cessation) reflect autonomic dysfunction (AD) and predict adverse cardiac prognosis. As chronic obstructive pulmonary disease (COPD) is known to be associated with AD, we hypothesized that these patients may manifest these responses on exercise. The prevalence and predictors of these responses in COPD and their association with its severity have not been evaluated. Normoxemic, stable male patients with COPD (n = 39) and 11 healthy controls underwent lung function testing and incremental leg ergometry. HR responses were monitored during exercise and recovery to compute the HRR and CI. Of all the patients, 33 (84.6%) had at least one of the two exercise responses as abnormal, with the majority (23, 58.9%) having both an abnormal HRR and CI. The frequency of abnormal responses increased with increasing Global Initiative for Chronic Obstructive Lung Disease stage and body mass index, airflow obstruction, dyspnoea and exercise capacity index. After adjusting for smoking history and post-bronchodilator forced expiratory volume in 1 second, only a reduced diffusion capacity for carbon monoxide predicted abnormal HRR, though weakly. We concluded that abnormal HRR and CI are common in patients with COPD. These responses are observed with increasing frequency as the severity of disease increases.

Possibilities of Checking Water Content in Porous Geopolymer Materials Using Impedance Spectroscopy Methods.

The porous geopolymer has been tested for its content of water using impedance methods. The pores of the material were filled with distilled water using a desiccator and a vacuum pump. An analysis of differential scanning calorimetry (DSC) was carried out in the next step to check the content of water, porosity and approximate value of specific heat of the geopolymer. Additionally, mercury porosimeter has been used for checking the porosity. The geopolymer material characterized in this way was subjected to impedance tests aimed at developing a quick method for assessing the water content in the material. Impedance measurements have been realized on an electrochemical workstation applying a 50 mV non-destructive amplitude of the potential and a frequency range of 1 Hz to 100 kHz. Change in the module of impedance and the phase shift angle were measured while the material was dried out. Significant differences were observed. The obtained graphs were simulated using a schematic model consisting of constant phase elements (CPEs) and a resistor (R). These values showed mechanisms of charge conduction. A simple method for assessing the water content of a porous geopolymer has been proposed in this paper. The real and imaginary impedance values were shown in Nyquist graphs. These graphs have characteristic maxima that move according to a linear equation with decreasing water content. Changes in Nyqiust charts are clearly visible even with small changes in the water content of the material and can be very useful for assessing it.

The Role of Multidimensional Indices for Mortality Prediction in Chronic Obstructive Pulmonary Disease.

(1) Background: Chronic obstructive pulmonary disease (COPD) is one of the most important respiratory diseases. It is characterised by a progressive course with individual differences in clinical presentation and prognosis. The use of multidimensional indices such as the BODE, eBODE, BODEX, CODEX, ADO, and Charlson Comorbidity Index has been proposed to predict the survival rate of COPD patients. However, there is limited research on the prognostic significance of these indices in predicting long-term survival rates in patients with COPD. The aim of this prospective cohort study was to investigate the prognostic value of the BODE, eBODE, BODEX, CODEX, ADO, COTE and Charlson Comorbidity Index in predicting 5- and 10-year survival in patients with COPD. (2) Methods: A total of 170 patients were included in the study and their clinical and functional characteristics of COPD progression, such as dyspnoea, body mass index and spirometry data, were evaluated. A Kaplan-Meier survival analysis was used to calculate 5- and 10-year survival rates. The predictive value of each index was assessed using Cox proportional hazards regression models. (3) Results: The 5-year survival rate was 62.35% and the 10-year survival rate was 34.70%. The BODE, eBODE, BODEX, CODEX, ADO, COTE and Charlson Comorbidity Index were all significantly associated with the 10-year survival rate of COPD patients (p < 0.05). The hazard ratios (HRs) for these indices were as follows: BODE (HR = 1.30, 95% confidence interval [CI] 1.21-1.39); eBODE (HR = 1.29, 95% CI 1.21-1.37); BODEX (HR = 1.48, 95% CI 1.35-1.63); CODEX (HR = 1.42, 95% CI 1.31-1.54); COTE (HR = 1.55, 95% CI 1.36-1.75); ADO (HR = 1.41, 95% CI 1.29-1.54); and Charlson Comorbidity Index (HR = 1.35, 95% CI 1.22-1.48). (4) Conclusions: The multidimensional indices are a useful clinical tool for assessing the course and prognosis of COPD. These indices can be used to identify patients at a high risk of mortality and guide the management of COPD patients.

Comment on "Optimal tuning of sigmoid PID controller using nonlinear sine cosine algorithm for the automatic voltage regulator system".

In this short note, the relative stability results (based on root locus and Bode analyses) reported in "Optimal tuning of sigmoid PID controller using nonlinear sine cosine algorithm for the automatic voltage regulator system" (Suid and Ahmad, 2022) are analyzed. It is shown that the use of closed-loop transfer functions (CLTFs) should be avoided in relative stability analysis since they may lead to less accurate stability results. The present study affirms that the results of relative stability analysis obtained using loop transfer functions (LTFs) are more reliable and accurate.