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The aim of the work is to study the effect of the 3D printing process on the microstructural and hydrophilic properties of polylactic acid (PLA) samples with various model printing patterns obtained from the black filament PLA by sequentially applying polymer layers using the FDM (fused deposition modeling) method. X-ray phase analysis revealed the partial crystallization of PLA polymer chains in the printed samples, which occurs under thermal and mechanical action on the original amorphous PLA filament during 3D printing to varying degrees, depending on the geometry of the pattern and the morphology of its surface. At the same time, IR spectroscopy data indicate the preservation of all intrastructural chemical bonds of polylactide. Measured at the original installation, the values of the wetting edge angles on the surface of the printed samples are in the range φ = 50-60°, which is significantly less than the right angle. This indicates the hydrophilic properties of the whole sample's surface. At the same time, the influence of different geometries of model drawings in printed samples was found not only on the morphology of the sample's surface according to SEM data but also on its wettability.
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Aiming to promote the application of D-mannitol in the field of phase change thermal storage, obstacles, including low thermal storage efficiency and high supercooling, should be properly disposed of. The adoption of adaptable and low-cost supporting materials to make shape-stable phase change materials (ss-PCMs) affordable is a primary solution to solve the above shortcomings. In this study, high-performance ss-PCM for effective medium-temperature heat storage was prepared using expanded vermiculite as the support for D-mannitol preservation. Among the three candidates that treated the raw vermiculite by dilute acid, calcination, and microwave heating, the calcinated expanded vermiculite (CV) was characterized as the most suitable one. After impregnating D-mannitol into the CV carrier by vacuum, a melting enthalpy of 205.1 J/g and a crystallization enthalpy of 174.1 J/g were achieved by the as-received CV/D-mannitol ss-PCM. Additionally, the supercooling of the ss-PCM was reduced to 45.6 °C. The novel CV/D-mannitol ss-PCM also exhibited excellent reusability and stability. All the findings indicate that the abundant and inexpensive CV exhibited great potential as the supporting material for D-mannitol-based ss-PCMs, which allow effective waste heat recovery and temperature regulation.
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Background & aims: Glioma patients experience a multitude of symptoms that negatively affect their health-related quality of life. Symptoms vary greatly across disease phases, and the patients' stable phase might be particularly suitable for assessing and treating symptoms. Identifying symptoms and patients' needs is a first step toward improving patient care. In glioma patients with stable disease, we assessed the frequency and burden of patient-reported symptoms, examined how these symptoms co-occur, and also determined whether patients would consider treatment to ameliorate specific symptoms. Methods: In this retrospective study, patients rated the frequency and burden of seventeen symptoms on a seven-point Likert scale and stated whether they would consider treatment for these symptoms. Correlations between frequency, burden, and considering treatment were evaluated with Kendall's Tau correlation coefficients. Based on partial correlations between symptom frequencies we visualized the symptoms as a network. Results: Fifty-two glioma patients with stable disease were included (31 WHO grade II/III, 21 WHO grade IV). The top five symptoms were fatigue, memory problems, reduced physical fitness, concentration problems, and drowsiness. Fatigue had the highest median frequency (4.5, interquartile range 2.5). Over half of the patients experienced three or more symptoms simultaneously and associations between all symptoms were depicted as a network. Overall, 35% of patients would consider treatment for at least one symptom. The wish to undergo symptom treatment correlated only moderately with symptom frequency and burden (range of correlations 0.24-0.57 and 0.28-0.61, respectively). Conclusion: Glioma patients with stable disease experience multiple symptoms with a consequently high symptom burden. Despite the high prevalence of symptoms, the inclination for symptom management interventions was relatively low. The most frequent and burdensome symptoms and the way they are interrelated could serve as a roadmap for future research on symptom management in these patients.
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BACKGROUND: Pulmonary rehabilitation training is an important means of stable chronic obstructive pulmonary disease (COPD). However, some people think that its effect is not satisfactory, and there is a lack of understanding of the effect of pulmonary rehabilitation training on T cell immune function. This study investigated the efficacy and safety of pulmonary rehabilitation training on lung function, quality of life and T cell immune function in stable COPD patients. METHODS: Seventy-two stable COPD patients recruited from the Outpatient department of Affiliated Hospital of Jiangnan University and Wuxi Huishan Rehabilitation Hospital, and divided them into experimental group (39 cases) and control group (33 cases) by random number table method. Both groups were received routine drug therapy, COPD knowledge education, and smoking cessation treatment. On this basis, the experimental group received daily pulmonary rehabilitation training, including pursed-lip breathing (PLB) training, abdominal breathing training, skeletal muscle training, and coughing and expectoration training. Lung function [percentage of forced expiratory volume in 1 second (FEV1%) and the percentage of FEV1/forced vital capacity (FEV1/FVC%)], quality of life [6-minute walk test (6MWT), COPD assessment test (CAT score)], and T lymphocyte subsets (CD3+%, CD4+%, CD8+%, and CD4+%/CD8+%) levels were compared by independent sample t-test or paired t-test between the 2 groups before and after 12 weeks of treatment in a double-blind method. RESULTS: There were no remarkable differences in lung function indexes, 6MWT, CAT score, and T cell immune function between the 2 groups before treatment. After 12 weeks, all indexes in the experimental group (all P<0.01) and T lymphocyte subsets in the control group (CD3+%, CD4+%, CD8+% and CD4+%/CD8+% were 0.010, 0.037, 0.021 and 0.016, respectively) were significantly better than before treatment, and there were no significant differences in lung function,6MWT, and CAT scores in the control group. After 12 weeks, all indexes in the experimental group were significantly better than those in the control group except CD8+% (FEV1%, FEV1/FVC%, 6MWT, CAT score, CD3+%, CD4+% and CD4+%/CD8+% were 0.002, 0.009, <0.001, 0.007, 0.037, 0.046 and <0.001, respectively). CONCLUSIONS: Pulmonary rehabilitation training can improve the lung function, quality of life, and T cell immune function of stable-phase COPD patients. Perhaps the recovery of T-cell immune function is the root of the patient's improvement. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2100048419.
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Doença Pulmonar Obstrutiva Crônica , Qualidade de Vida , Humanos , Imunidade , Pulmão , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Linfócitos TRESUMO
BACKGROUND: Heart failure with preserved ejection fraction (HFpEF) is a disorder related to patient comorbidities and aging. Whether mitochondrial dysfunction is present during HFpEF decompensation versus the stable phase is largely unknown. The aim of the present study was to identify mitochondrial and cell metabolism blood biomarkers in older patients with acute and stable HFpEF. METHODS: Peripheral blood biomarkers were investigated in a group of eight to 12 patients aged 80-96 years and diagnosed with HFpEF first when they were in decompensated phase and then at least three months later in stable phase. Their data were compared to two control groups with an equal number of participants and sex proportions. One group was age matched and the other included individuals aged between 22 and 44 years. RESULTS: Decompensated patients experienced an increased mitochondrial superoxide production and mitochondrial mass, lower mitochondrial DNA copy number and LDHB expression, and higher lactate level compared to the stable stage. The stable phase was characterized by a sharp reduction in formate level. Multivariate analysis indicated that formate, lactate, and histidine can distinguish both of the HFpEF phases. Many of these parameters, including LDHB, lactate, formate, and mitochondrial mass, followed an age-related pattern, with acute HFpEF at its apex or nadir, suggesting that it represents an exacerbation of an aging-related process. CONCLUSIONS: We identified distinct blood biomarkers of chronic and decompensated HFpEF phases. The data underlined the relationship between HFpEF and aging. These findings could be used to monitor patients and might be therapeutically targeted.
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Insuficiência Cardíaca , Adulto , Idoso , Biomarcadores , Formiatos , Humanos , Lactatos , Volume Sistólico , Adulto JovemRESUMO
Herein, we report a remotely controlled soft robot employing a photoresponsive nanocomposite synthesized from liquid crystal elastomers (LCEs), high elastic form-stable phase change polymer (HEPCP), and multiwalled carbon nanotubes (MWCNTs). Possessing a two-stage deformation upon exposure to near-infrared (NIR) light, the LCE/HEPCP/MWCNT (LHM) nanocomposite allows the soft robot to exhibit an obvious, fast, and reversible shape change with low detection limitations. In addition to the deformation and bending of the LCE molecular chains itself, the HEPCP in the composite material can also be triggered by a reversible solid-liquid transition due to the temperature rise caused by MWCNTs, which further promotes the change of the LCE. In particular, the proposed photodriven LHM soft robot can bend up to 180° in 2 s upon NIR stimulation (320 mW, distance of 5 cm) and generate recoverable, dramatic, and sensitive deformation to execute various tasks including walking, twisting, and bending. With the capacity of imitating biological behaviors through remote control, the disruptive innovation developed here offers a promising path toward miniaturized untethered robotic systems.
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BACKGROUND: The relationship between C3a-C3aR, IL-1ß, and the acute exacerbation of chronic obstructive pulmonary disease is still unclear. This study aims to explore the expression levels of C3aR in peripheral blood WBCs and the concentrations of C3a, C3aR, and IL-1ß in plasma in healthy controls and patients with chronic obstructive pulmonary disease (COPD). METHODS: WBCs C3aR level in the peripheral blood, the concentrations of C3a, C3aR, and IL-1ß in plasma were measured in 60 patients with acute exacerbation of COPD (AECOPD), 30 patients with stable COPD (SCOPD), and 30 healthy controls. The baseline characteristics and clinical data collected from enrolled patients, including age, gender, laboratory indicators, and lung function. We analyzed the correlation between C3a, C3aR, IL-1ß, and lung function indicators (forced expiratory volume in the first second as a percentage of predicted value, FEV1%pred) in the AECOPD group. RESULTS: The white blood cell count (WBC), neutrophil/lymphocyte ratio (NLR), and C-reactive protein (CRP) of patients in COPD were higher than in healthy controls (P < 0.05). The peripheral blood WBCs C3aR mRNA and plasma C3a, C3aR, and IL-1ß in AECOPD were higher than in SCOPD and healthy controls (P < 0.05). The peripheral blood WBCs C3aR mRNA and plasma C3aR, and IL-1ß in AECOPD combined with respiratory failure were higher than in the non-respiratory failure group (P < 0.05). The peripheral blood WBCs C3aR mRNA and plasma C3a, C3aR, and IL-1ß in AECOPD with high-risk were higher than in the low-risk group (P < 0.05). The peripheral blood WBCs C3aR mRNA and plasma C3a, C3aR, and IL-1ß in AECOPD were negatively correlated with FEV1pred%. The peripheral blood WBCs C3aR mRNA, the plasma C3a and C3aR in AECOPD were positively correlated with IL-1ß. CONCLUSION: The peripheral blood WBCs C3aR mRNA and plasma C3a, C3aR, and IL-1ß in COPD patients were significantly related to the risk of disease deterioration. The C3a-C3aR axis may be involved in airway inflammation in patients with COPD.
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Doença Pulmonar Obstrutiva Crônica , Estudos de Casos e Controles , Complemento C3/química , Volume Expiratório Forçado , Humanos , Interleucina-1beta/sangue , Doença Pulmonar Obstrutiva Crônica/diagnóstico , RNA Mensageiro/sangue , Receptores de Complemento/sangue , Testes de Função RespiratóriaRESUMO
This study analyzed the advantages and disadvantages of existing animal models in China and abroad and their goodness of fit based on the clinical characteristics and diagnostic criteria of stable chronic obstructive pulmonary disease(COPD) in traditional Chinese medicine(TCM) and western medicine, followed by the collation and summarization of model evaluation methodologies. The results showed that the existing animal models of stable COPD were mainly modeled via smoke exposure or the combination of multiple methods like smoke exposure plus lipopolysaccharide or protease or bacterial infection. These animal models generally failed to simulate the clinical characteristics of TCM, and their goodness of fit in western medicine was higher than that in TCM. There is a lack of research on the animal models of stable COPD and the disease-syndrome combination models. Although the modeling is guided by the pathogenesis or mechanism of diseased humans, the established models were still not identical with the actual clinical situations. In-depth research is needed to develop quantitative standards for stable COPD models.
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Medicamentos de Ervas Chinesas , Medicina , Doença Pulmonar Obstrutiva Crônica , Animais , Modelos Animais de Doenças , Humanos , Medicina Tradicional Chinesa , Modelos Animais , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , SíndromeRESUMO
OBJECTIVE: To investigate the effect of pulmonary rehabilitation training on pulmonary function and exercise tolerance in patients with stable chronic obstructive pulmonary disease (COPD). METHODS: By a random number table method, 90 patients with COPD admitted to our hospital from January 2019 to January 2020 were divided into three groups: the control group (conventional treatment), the observation group A (conventional treatment + pulmonary rehabilitation training three times a week) and the observation group B (conventional treatment + pulmonary rehabilitation training five times a week), with 30 patients in each group. The pulmonary function, exercise tolerance (the 6-min walking distance (6MWD)), sleep quality (Pittsburgh Sleep Quality Index (PSQI)) and quality of life (generic quality of life inventory-74 (GQOLI-74)) before and after intervention were compared among the three groups. Also, the satisfaction rate was recorded in all groups. RESULTS: After 6 months of intervention, the FEV1%, FVC% and FEV1/FVC as well as the GQOLI-74 scores increased significantly, while the PSQI scores decreased markedly in all groups as compared to those before intervention; the index levels and GQOLI-74 scores were significantly higher, and PSQI scores were markedly lower in the observation group B than in the other two groups (all P<0.05). After 3 and 6 months of intervention, the 6MWDs of the three groups were significantly increased compared with those before intervention, and the 6MWD was significantly longer in the observation group B than in the other two groups (P<0.05). Moreover, the satisfaction rate was significantly higher in observation group B than in the other two groups (P<0.05). CONCLUSION: For patients with stable COPD, pulmonary rehabilitation training based on drug therapy can improve the pulmonary function, exercise tolerance, sleep quality and quality of life more effectively than drug treatment alone. What's more, the therapeutic effect of training five times a week is significantly better than that of training three times a week.
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Photothermal/electrothermal advanced functional form-stable phase change materials (FSPCMs) can efficiently make use of solar energy and electrical energy by using supporting materials to encapsulate phase change materials. Herein, a novel low-cost integrated supporting material, denoted PDVB-12/PPy NTs, is quickly constructed via wrapping the polypyrrole (PPy) on the mesoporous polydivinylbenzene nanotubes (PDVB-12 NTs) through a fast oxidative initiation method. PDVB-12/PPy NTs exhibits good loading capacity (72.9 wt %) for industrial paraffin wax (IPW) due to the large specific surface area, and the resulting FSPCM composite (IPW@PDVB-12/PPy) exhibits a large latent heat of fusion (145.7 J/g), high thermal stability, and excellent shape stability. In addition, PPy imparts the IPW@PDVB-12/PPy composite with high electrical conductivity (55.6 S m-1) and high photoabsorption ability (whole visible light band). The energy stored in the IPW@PDVB-12/PPy composite could be triggered and released under relatively low voltages (2.5 V) with electrothermal energy conversion efficiency (89.6%) or solar radiation (100 mW cm-2) with photothermal energy conversion efficiency (85.2%). This study provides a low-cost and fast method for large-scale fabrication of supporting materials, which can be a good candidate in energy storage applications.
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The present study was aimed at investigating the bacterial community in lactic acid bacteria (LAB) suspensions prepared from whole-plant corn silage (LAB suspension-CS) and Elymus sibiricus silage (LAB suspension-ES) and the bacterial community succession of whole-plant corn silages inoculated with LAB suspension-CS or LAB suspension-ES during initial aerobic phase, intense fermentation phase, and stable phase. The LAB suspensions were cultured in sterile Man, Rogosa, Sharpe broth at 37°C for 24 h and used as inoculants for ensiling. The chopped whole-plant corn was treated with distilled water (CK), LAB suspension-CS (CSL), or LAB suspension-ES (ESL) and then ensiled in vacuum-sealed plastic bags containing 500 g of fresh forage. Silages were sampled at 0 h, anaerobic state (A), 3 h, 5 h, 10 h, 24 h, 2 days, 3 days, 10 days, 30 days, and 60 days of ensiling with four replicates for each treatment. The results showed that Lactobacillus, Weissella, and Lachnoclostridium_5 dominated the bacterial community in LAB suspension-CS; Lactobacillus was the most predominant bacterial genus in LAB suspension-ES. During the initial aerobic phase (from 0 h to A) of whole-plant corn silage, the pH and the abundances of Pantoea, Klebsiella, Rahnella, Erwinia, and Serratia increased. During the intense fermentation phase (from A to 3 days), the pH decreased rapidly, and the microbial counts increased exponentially; the most predominant bacterial genus shifted from Pantoea to Weissella, and then to Lactobacillus; inoculating LAB suspensions promoted the bacterial succession and the fermentation process, and LAB suspension-CS was more effective than LAB suspension-ES. During the stable phase (from 3 to 60 days), the pH and the microbial counts decreased, and Lactobacillus dominated the bacterial community with a little decrease. The results also confirmed the existence of LAB fermentation relay during fermentation process, which was reflected by Weissella, Lactococcus, and Leuconostoc in the first 5 h; Weissella, Lactococcus, Leuconostoc, Lactobacillus, and Pediococcus between 5 and 24 h; and Lactobacillus from 24 h to 60 days.
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Organic phase change materials (PCMs) have attracted considerable attention for thermal energy storage applications because of their non-toxicity, suitable working temperature range and excellent thermal/chemical stability. However, most traditional organic PCMs have small molecular structures and are prone to leakage during fusion. To address this problem and enhance the shape-stability of organic PCMs, nanosphere-shaped porphyrin-ferrocenyl conjugated microporous polymers (PFCMPs) with high porosity (~ 650 m2/g) were solvothermally synthesized using a Diels-Alder reaction between 1,1'-ferrocenedicarboxaldehyde and pyrrole in the presence of glacial acetic acid and anhydrous Lewis acids (FeCl3, AlCl3, and CuCl2). The PFCMPs were then encapsulated with PCMs, that is, 1-octadecanol (ODA), to prepare the composite materials of ODA@PFCMPs. The optimized composite exhibited a high latent heat (up to 153.8 J/g), excellent reversibility (negligible change in latent heat upon 100 cycles of heating-cooling), good shape stability, and long heat storage durability (425 s), making it a promising candidate for solar thermal energy engineering and management.
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By referring to the standards and procedures of WHQ Handbook for Guideline Development, under the guidance of relevant laws, regulations, and technical documents, in line with the principle of "evidence-based, consensus-based, experience-based", and based on the best available evidences, fully combined with expert experience and patient preferences, we summarized eight clinical questions in this paper: can traditional Chinese medicine(TCM) treatment improve the clinical symptoms and the degree of dyspnea in patients with stable chronic obstructive pulmonary disease(COPD) Can TCM treatment reduce the number of exacerbations in patients with stable COPD? Can TCM treatment improve the exercise tolerance of patients with stable COPD? Can TCM treatment improve the quality of life of patients with stable COPD? Can TCM treatment delay the decline of lung function in patients with stable COPD? Can TCM treatment improve anxiety and depression in patients with stable COPD? Does the point application therapy benefit patients with stable COPD? Can non-pharmacological treatment benefit patients with stable COPD? Based on these eight clinical problems, the cha-racteristics of TCM itself, and actual clinical situation, the recommendations of TCM to treat the stable COPD were formed in this guideline, with intention to provide advice and guidance to clinicians in the use of TCM to treat stable COPD, to relieve symptoms, improve exercise tolerance, improve health status, prevent disease progression, prevent and treat exacerbations, and improve clinical efficacy. Due to the influence of the user's region, nationality, race and other factors, the implementation of this guideline should be based on the actual situations.
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Medicina Tradicional Chinesa , Doença Pulmonar Obstrutiva Crônica , Dispneia , Humanos , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Qualidade de Vida , Resultado do TratamentoRESUMO
Polyethylene glycol (PEG)-based composite phase change materials (PCMs) containing hydroxylated boron nitride (BN-OH), cellulose nanofiber (CNF), and chitosan (CS) were prepared by the method of interfacial polyelectrolyte complex spinning, based on in-situ ionic cross-linking between CNF and CS. The wrapping effect of cross-linked CNF/CS networks and the strong interfacial interactions contributed to superior shape-stability throughout the phase change process. Furthermore, the homogeneously dispersed BN-OHs was beneficial to the construction of the continuous thermal conductive paths, and the excellent interfacial interactions between BN-OH and the matrix would lower the heat loss caused by phonon scattering in the interface. As a result, the thermal conductivity of the PCMs containing 47.5 wt% BN-OH reached 4.005 W/mK, which was 22.56 times higher than that of the pure PEG. Combined with the excellent thermal reliability and thermal stability, the form-stable PCMs showed a promising application potential in the fields of electronic cooling or temperature-adaptable textiles.
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OBJECTIVE: The pathogenesis of chronic obstructive pulmonary disease (COPD) remains elusive. Here, we assessed the correlation between CD8+ T cell frequencies and autophagy in COPD patients. METHODS: Subjects were divided into three groups (n = 30 patients/group): (1) COPD patients in the stable phase; (2) smokers with normal lung function; and (3) non-smokers with normal lung function. Flow cytometry was used to enumerate CD8+ T cell subsets (CD8+, CD8+ effector, and CD8+ memory T cells) and quantitate T-cell apoptosis. RT-PCR and western blotting were used to measure levels of LC3 and p62. RESULTS: Frequencies of CD8+ T cell subsets and expression of p62 and LC3 II/I were significantly higher in COPD patients compared with the other two groups, while the rate of apoptosis was lower. In COPD patients, LC3 II/I and p62 expression were positively correlated with CD8+ T cell subset frequencies. Moreover, a significant correlation was observed between LC3 II/I and p62 expression and T cell subset frequencies. CONCLUSION: Autophagy level is positively correlated with the frequencies of CD8+ T cells, suggesting that autophagy might be involved in COPD pathogenesis.
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Doença Pulmonar Obstrutiva Crônica , Fumar , Autofagia , Linfócitos T CD8-Positivos , Humanos , Subpopulações de Linfócitos TRESUMO
In this work, the influence of molecular parameters of styrene-b-(ethylene-co-butylene)-b-styrene (SEBS) triblock copolymer as matrix material in form-stable phase change material (FSPCM) on the thermo-mechanical properties and leakage behavior are studied. Various SEBS grades differing in their molecular weight, styrene content, and ethylene/butylene ratio are used as supporting matrix in composites with 90 wt.% paraffin. Thermo-mechanical properties are determined by rheological measurements. The results show phase transitions temperatures from solid to hard gel, hard gel to soft gel, and soft gel to gel fluid. Paraffin leakage in FSPCM is analyzed by mass loss over time in an oven at 60 °C. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) are applied to determine the thermal energy storage capacity. Finally, the molecular weight and the styrene content are combined to the molecular weight of styrene block which is identified as the authoritative parameter for the thermo-mechanical properties of the SEBS/PCM composite.
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The practical application of shape-stable phase change composites (PCCs) is beneficial to thermal energy management and energy conservation due to their superior properties. A shape-stable PCC was fabricated by incorporating poly(ethylene glycol) (PEG) with biomass-based porous carbon that was produced via freeze-drying and carbonization using a low-cost and environmentally friendly fresh towel gourd. The towel gourd derived porous carbon with the characteristics of porosity, unique three-dimensional (3D) lamellar structure, and high specific surface area allowed a high encapsulation capacity (up to 94.5 wt %) for PEG. Structural morphologies, as well as the properties of latent heat storage, thermal reliability, thermal energy management, and thermal protection ability of the fabricated shape-stable PCC, were investigated. The micromorphologies revealed that PEG molecular chains were arranged in a 3D lamellar tissue structure. The shape-stable PCC demonstrated excellent thermal reliability and a high melting latent heat of â¼164.3 J/g. The analysis of infrared thermal images indicated that the shape-stable PCC exhibited remarkable strengths in thermal energy management. The result of the thermal insulation simulation experiment proved that the shape-stable PCC had superior thermal protection ability. This study provided an innovative strategy for the design and development of shape-stable PCCs for great potential in heat-insulating protective textiles, solar thermal energy storage, energy-saving buildings, and infrared stealth of military targets.
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In this paper, diatomite-based composite phase change materials (DI-based CPCMs) were fabricated by the vacuum impregnation of capric acid (CA) into reduced graphene oxide decorated diatomite (rGO-DI). In the DI-based CPCMs, DI was used as the supporting material, which was first purified by thermal treatment and alkali treatment, to improve the adsorption capacity of the PCM, rGO was used to decorate the DI to improve the thermal conductivity of CPCMs. The rGO-DI could retain CA at the weight fraction of 60% without leakage. The maximum melting and freezing enthalpy of CA/rGO-DI-2 reached 106.2 J g-1 and 108.6 J g-1, respectively, and its thermal conductivity was up to 0.5226 W m-1 · K, 260.4% and 81.3% higher than pure CA and CA/DI, respectively. The CPCMs have good thermal reliability and thermal stability, and there was no chemical reaction between CA and rGO-DI. The CPCMs maintained thermal properties after 200 melting-freezing cycles. Finally, the CPCMs have potential for application in solar energy storage systems.
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Alkyl chains of ß-hydroxyesters synthesized by the capping of terminal epoxy groups of diglycidylether of bisphenol A (DGEBA) with palmitic (C16), stearic (C18), or behenic (C22) fatty acids self-assemble forming a crystalline phase. Above a particular concentration solutions of these esters in a variety of solvents led to supramolecular (physical) gels below the crystallization temperature of alkyl chains. A form-stable phase change material (FS-PCM) was obtained by blending the ester derived from behenic acid with eicosane. A blend containing 20 wt % ester was stable as a gel up to 53 °C and exhibited a heat storage capacity of 161 J/g, absorbed during the melting of eicosane at 37 °C. Thermally reversible light scattering (TRLS) films were obtained by visible-light photopolymerization of poly(ethylene glycol) dimethacrylate-ester blends (50 wt %) in the gel state at room temperature. The reaction was very fast and not inhibited by oxygen. TRLS films consisted of a cross-linked methacrylic network interpenetrated by the supramolecular network formed by the esters. Above the melting temperature of crystallites formed by alkyl chains, the film was transparent due to the matching between refractive indices of the methacrylic network and the amorphous ester. Below the crystallization temperature, the film was opaque because of light dispersion produced by the organic crystallites uniformly dispersed in the material. Of high significance for application was the fact that the contrast ratio did not depend on heating and cooling rates.
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OBJECTIVE: This study assessed the postural stability in children with asthma using balance tests under conditions of a comfortable foot placement and with a foot placement provoking instability. METHODS: A group of 10 school children from 8 to 10 years old with mild intermittent asthma and 10 healthy children of the same age range performed four balance tests in a randomized order: preferred stance, adjusted stance, and tandem stance each under both conditions of eyes opened (EO) and eyes closed (EC), as well as a one-legged stance with eyes-opened conditions. To determine postural stability, the center of pressure (CoP) movement was recorded. Basic stabilographic parameters were calculated: CoP velocity in the anterior-posterior direction, CoP velocity in the medial-lateral direction, and the total CoP velocity. RESULTS: Statistically significant differences between the groups were found only for the one-legged stance. Significantly greater anterior-posterior CoP velocity (p = 0.05) and total CoP velocity (p = 0.03) were found in children with asthma when standing on the preferred foot. A significantly greater medial-lateral velocity (p = 0.02) was also found in the non-preferred foot of children with asthma. CONCLUSIONS: We can conclude that standing on one leg might be an appropriate test with which to identify balance differences between young children with mild intermittent asthma and healthy children.