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Static Stretching Combined with Conscious Slower Breathing May Increase Parasympathetic Activity and Reduce Stress in Adult Women
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作者 Mami Sakurai Yasushi Ikarashi +3 位作者 Masahiro Tabuchi Ailing Hu Takuji Yamaguchi Hiroyuki Kobayashi 《Health》 2024年第3期242-256,共15页
Background: Women are thought to be more susceptible to stress than men in a stressful society, and reducing stress is crucial for women to maintain their health. Static stretching (SST) is applied in various fields t... Background: Women are thought to be more susceptible to stress than men in a stressful society, and reducing stress is crucial for women to maintain their health. Static stretching (SST) is applied in various fields to not only increase muscle flexibility but also reduce stress. Additionally, conscious slower breathing (CSB) predominates parasympathetic activity, causing a relaxing effect. These results indicate that combining SST and CSB may be more useful in reducing stress. However, to the best of our knowledge, the effect of this combination remains unclear. Objective: This study aimed to elucidate the effects of the combination of SST and CSB on autonomic activity and stress in adult women. Methods: Eleven healthy Japanese adult female participants performed SST with nonconscious natural breathing for 20 min. The same participants performed SST in combination with CSB (2 s inspiratory and 4 s expiratory) for 20 min on another day. Salivary cortisol and chromogranin A levels were measured before and after stretching as stress markers of the hypothalamic-pituitary-adrenal axis and sympathetic nervous system. The coefficient of variation of the R-R interval (CVR-R) and high-frequency component (HF), which reflect parasympathetic nerve activity, and heart rate and low-frequency component (LF)/HF ratio, which reflect sympathetic nerve activity, were measured before, during, and after stretching. Results: SST decreased cortisol levels but with no significant changes in chromogranin A, heart rate, CVR-R, HF, or LF/HF ratio. The combination of SST and CSB increased CVR-R and HF levels in addition to decreasing cortisol levels but with no significant changes in chromogranin A, heart rate, or LF/HF levels. Conclusion: These results indicate that the combination of SST and CSB may increase parasympathetic activity and reduce stress. However, future randomized controlled trials with larger sample sizes should support this conclusion. 展开更多
关键词 Static Stretching Conscious Slower breathing Autonomic Activity Heart Rate Variability STRESS
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Analysis of the Effect of Psychological Nursing Combined with Breathing Exercises in Improving Lung Function in Patients with Pneumoconiosis
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作者 Jing Huang 《Occupational Diseases and Environmental Medicine》 2024年第1期35-40,共6页
Objective: To analyze the effect of psychological nursing combined with breathing exercises on lung function of patients with pneumoconiosis, and to analyze the methods. A total of 64 cases of pneumoconiosis admitted ... Objective: To analyze the effect of psychological nursing combined with breathing exercises on lung function of patients with pneumoconiosis, and to analyze the methods. A total of 64 cases of pneumoconiosis admitted from January 2020 to December 2022 were divided into the reference group and the experimental group by random numerical table. On the basis of symptomatic treatment, the control group was combined with conventional nursing measures and breathing exercises, while the experimental group was treated with psychological nursing on the basis of the control group, and the pulmonary function indexes and adverse mood of the two groups before and after nursing were compared. Results: There was no difference in SAS score, SDS score and pulmonary function indexes between the two groups before intervention (P > 0.05), and the SAS score in the experimental group was the SDS score was lower than that of the control group, and FEV1, FEV1% and FEV1/FVC were higher than those of the control group, and the P < 0.05 was lower. 展开更多
关键词 PNEUMOCONIOSIS Psychological Nursing breathing Exercises Lung Function
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Effects of relaxation breathing exercise on fatigue and cortisol level among Indonesian gynecological cancer patients undergoing chemotherapy:a pilot study
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作者 Mulhaeriah Mulhaeriah Mohammad Syafar Sangkala +1 位作者 Syahrul Syahrul Rezki Wahyuni 《Frontiers of Nursing》 2024年第2期201-208,共8页
Objective:This study aimed to determine the effect of the relaxation breathing exercise(RBE)on fatigue and cortisol levels among Indonesian women with gynecological cancer undergoing chemotherapy.Methods:This pilot st... Objective:This study aimed to determine the effect of the relaxation breathing exercise(RBE)on fatigue and cortisol levels among Indonesian women with gynecological cancer undergoing chemotherapy.Methods:This pilot study consecutively recruited 44 gynecological cancer patients to receive RBE(22)or usual care(22).Cortisol level was measured before and after completion of the intervention(day 8).Fatigue was measured using the Piper Fatigue Scale(PFS).Anxiety and depression were assessed using the Hospital Anxiety and Depression Scale(HADS)at the baseline days of the study for days 1,4,and 8.The obtained data were analyzed using Fisher’s exact test,the independent t-test,and the Mann-Whitney U test.Results:There were significant increases in cortisol levels within the groups,either the intervention or control groups,respectively(P-value=0.0003 and 0.001).Despite there being no statistical significance between the intervention and control groups,there were noticeable differences in the cortisol levels,indicating the extreme increase in cortisol levels in the control group(Median[IQR1-IQR3]:2.30[0.99-9.09];Min-Max:0.43-23.38)compared with the intervention group(Median[IQR1-IQR3]=2.97[1.26-5.18];Min-Max=0.39-6.91).Conclusions:RBE helps prevent a significant increase in cortisol levels that can alleviate fatigue for women with gynecological cancer.Further research was recommended to compare several intervention modalities for fatigue and cancer-related symptom management based on cortisol level changes. 展开更多
关键词 ANXIETY CORTISOL FATIGUE gynecological cancer relaxation breathing exercise
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The Importance of Breathing Training in Folk Dance Teaching
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作者 Xiaowei Sun 《Journal of Contemporary Educational Research》 2024年第4期187-192,共6页
The importance of breathing training in dance teaching is reflected in the two aspects of enhancing the quality of dance movements and sublimating the connotation of dance movements.For example,high-quality breathing ... The importance of breathing training in dance teaching is reflected in the two aspects of enhancing the quality of dance movements and sublimating the connotation of dance movements.For example,high-quality breathing can help performers complete the dance movements and improve the coordination of the movements;at the same time,the unique body rhythm formed by breathing can strengthen the visual effect of the performance and convey its spirit and soul to the audience.This requires folk dance teachers to carry out relevant training and teaching activities based on the categories and skills of dance breathing,such as changing students’ideological cognition,developing periodic breathing training courses,providing personalized guidance to students,and allowing students to adjust their learning and practice methods in the evaluation. 展开更多
关键词 Folk dance teaching breathing training IMPORTANCE Training methods
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Conscious Slower Breathing Predominates Parasympathetic Activity and Provides a Relaxing Effect, in Healthy Japanese Adult Women
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作者 Mami Sakurai Ailing Hu +3 位作者 Takuji Yamaguchi Masahiro Tabuchi Yasushi Ikarashi Hiroyuki Kobayashi 《Health》 2023年第9期954-964,共11页
Background: The optimal breathing pattern (BP) to effectively regulate autonomic nervous activity is yet to be determined. Objective: We aimed to clarify the effects of four BPs (BP-1, BP-2, BP-3, and BP-4) on autonom... Background: The optimal breathing pattern (BP) to effectively regulate autonomic nervous activity is yet to be determined. Objective: We aimed to clarify the effects of four BPs (BP-1, BP-2, BP-3, and BP-4) on autonomic nervous activity and mood changes. Methods: Eleven healthy adult female volunteers performed each BP in a sitting position for 5 min in a resting state. The time required for one breathing for BP-1 (30 breaths/min), BP-2 (20 breaths/min), BP-3 (15 breaths/min), and BP-4 (10 breaths/min) were 2 s, 3 s, 4 s, and 6 s, respectively. The inspiratory/expiratory time of one breathing was 1 s/1 s, 1 s/2 s, 2 s/2 s, and 2 s/4 s. The high-frequency component (HF) and low-frequency component (LF)/HF ratio during and before (control) performing a BP were calculated from heart rate variability data recorded using the wearable biometric information tracer M-BIT. Three mood changes, which are, “pleasure—unpleasure”, “relaxation—tension”, and “sleepiness—arousal”, in the subjects were assessed using the visual analog scale (VAS) before and after performing a BP. Results: Slower breathing induced an increase in HF power and a reduction in LF/HF ratio, indicating increased parasympathetic activity and decreased sympathetic dominance. Furthermore, VAS revealed that slower breathing increased the tendency to feel “pleasure”, “relaxation”, and “sleepiness”. Conclusion: Our results suggest that slower breathing predominates parasympathetic activity in the autonomic nervous system, resulting in a relaxing effect. This result may help lay the foundation for deriving breathing methods that efficiently regulate an individual’s autonomic activity. 展开更多
关键词 breathing Autonomic Activity Heart Rate Variability Analysis Visual Analog Scale
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Recognition System for Diagnosing Pneumonia and Bronchitis Using Children’s Breathing Sounds Based on Transfer Learning
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作者 Jianying Shi Shengchao Chen +3 位作者 Benguo Yu Yi Ren Guanjun Wang Chenyang Xue 《Intelligent Automation & Soft Computing》 SCIE 2023年第9期3235-3258,共24页
Respiratory infections in children increase the risk of fatal lung disease,making effective identification and analysis of breath sounds essential.However,most studies have focused on adults ignoring pediatric patient... Respiratory infections in children increase the risk of fatal lung disease,making effective identification and analysis of breath sounds essential.However,most studies have focused on adults ignoring pediatric patients whose lungs are more vulnerable due to an imperfect immune system,and the scarcity of medical data has limited the development of deep learning methods toward reliability and high classification accuracy.In this work,we collected three types of breath sounds from children with normal(120 recordings),bronchitis(120 recordings),and pneumonia(120 recordings)at the posterior chest position using an off-the-shelf 3M electronic stethoscope.Three features were extracted from the wavelet denoised signal:spectrogram,mel-frequency cepstral coefficients(MFCCs),and Delta MFCCs.The recog-nition model is based on transfer learning techniques and combines fine-tuned MobileNetV2 and modified ResNet50 to classify breath sounds,along with software for displaying analysis results.Extensive experiments on a real dataset demonstrate the effectiveness and superior performance of the proposed model,with average accuracy,precision,recall,specificity and F1 scores of 97.96%,97.83%,97.89%,98.89%and 0.98,respectively,achieving superior performance with a small dataset.The proposed detection system,with a high-performance model and software,can help parents perform lung screening at home and also has the potential for a vast screening of children for lung disease. 展开更多
关键词 Deep learning breath sounds transfer learning signal denoising
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Evaluation of urea breath test as a diagnostic tool for Helicobacter pylori infection in adult dyspeptic patients
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作者 Zeinab Nabil Ahmed Said Asmaa Mohamed El-Nasser 《World Journal of Gastroenterology》 SCIE CAS 2024年第17期2302-2307,共6页
In this editorial,we discuss the article in the World Journal of Gastroenterology.The article conducts a meta-analysis of the diagnostic accuracy of the urea breath test(UBT),a non-invasive method for detecting Helico... In this editorial,we discuss the article in the World Journal of Gastroenterology.The article conducts a meta-analysis of the diagnostic accuracy of the urea breath test(UBT),a non-invasive method for detecting Helicobacter pylori(H.pylori)infection in humans.It is based on radionuclide-labeled urea.Various methods,both invasive and non-invasive,are available for diagnosing H.pylori infection,inclu-ding endoscopy with biopsy,serology for immunoglobulin titers,stool antigen analysis,and UBT.Several guidelines recommend UBTs as the primary choice for diagnosing H.pylori infection and for reexamining after eradication therapy.It is used to be the first choice non-invasive test due to their high accuracy,specificity,rapid results,and simplicity.Moreover,its performance remains unaffected by the distribution of H.pylori in the stomach,allowing a high flow of patients to be tested.Despite its widespread use,the performance characteristics of UBT have been inconsistently described and remain incompletely defined.There are two UBTs available with Food and Drug Administration approval:The 13C and 14C tests.Both tests are affordable and can provide real-time results.Physicians may prefer the 13C test because it is non-radioactive,compared to 14C which uses a radioactive isotope,especially in young children and pregnant women.Although there was heterogeneity among the studies regarding the diagnostic accuracy of both UBTs,13C-UBT consistently outperforms the 14C-UBT.This makes the 13C-UBT the preferred diagnostic approach.Furthermore,the provided findings of the meta-analysis emphasize the significance of precise considerations when choosing urea dosage,assessment timing,and measurement techniques for both the 13C-UBT and 14C-UBT,to enhance diagnostic precision. 展开更多
关键词 Helicobacter pylori Urea breath test DIAGNOSIS Diagnostic test accuracy META-ANALYSIS
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Advancements in breath-based diagnostics for pancreatic cancer:Current insights and future perspectives
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作者 Mesut Tez Eda Sahingoz Huseyin Fahri Martli 《World Journal of Gastrointestinal Oncology》 SCIE 2024年第6期2300-2303,共4页
Recent decades have seen a concerning surge in carcinogenic diseases,with cancer cases and deaths on the rise globally.Conventional diagnostic methods are often invasive and time-consuming,highlighting the need for fa... Recent decades have seen a concerning surge in carcinogenic diseases,with cancer cases and deaths on the rise globally.Conventional diagnostic methods are often invasive and time-consuming,highlighting the need for fast,accurate,and painless alternatives.Non-invasive exhaled breath analysis emerges as a promising solution,with over 200 volatile organic compounds(VOCs)detected in exhaled air,showing potential as biomarkers for various diseases,including cancer.Despite the lack of standardized methodologies,advancements in analytical instruments have expanded detection capabilities,reaching 3500 VOCs.Studies have identified specific VOC patterns associated with different cancers,offering hope for non-invasive diagnosis.Techniques such as gas chromatography-mass spectrometry and electronic noses show promise in distinguishing between healthy individuals and cancer patients.However,further research and standardization are needed to realize the full clinical potential of breath-based diagnostics,particularly in the early detection of challenging cancers like pancreatic cancer. 展开更多
关键词 PANCREAS Volatile organic compounds Diagnosis Cancer breath
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Identification of breath volatile organic compounds to distinguish pancreatic adenocarcinoma,pancreatic cystic neoplasm,and patients without pancreatic lesions
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作者 Kasenee Tiankanon Nuttanit Pungpipattrakul +2 位作者 Thanikan Sukaram Roongruedee Chaiteerakij Rungsun Rerknimitr 《World Journal of Gastrointestinal Oncology》 SCIE 2024年第3期894-906,共13页
BACKGROUND Volatile organic compounds(VOCs)are a promising potential biomarker that may be able to identify the presence of cancers.AIM To identify exhaled breath VOCs that distinguish pancreatic ductal adenocar-cinom... BACKGROUND Volatile organic compounds(VOCs)are a promising potential biomarker that may be able to identify the presence of cancers.AIM To identify exhaled breath VOCs that distinguish pancreatic ductal adenocar-cinoma(PDAC)from intraductal papillary mucinous neoplasm(IPMN)and healthy volunteers.METHODS We collected exhaled breath from histologically proven PDAC patients,radiological diagnosis IPMN,and healthy volunteers using the ReCIVA®device between 10/2021-11/2022.VOCs were identified by thermal desorption-gas chromatography/field-asymmetric ion mobility spectrometry and compared between groups.RESULTS A total of 156 participants(44%male,mean age 62.6±10.6)were enrolled(54 PDAC,42 IPMN,and 60 controls).Among the nine VOCs identified,two VOCs that showed differences between groups were dimethyl sulfide[0.73 vs 0.74 vs 0.94 arbitrary units(AU),respectively;P=0.008]and acetone dimers(3.95 vs 4.49 vs 5.19 AU,respectively;P<0.001).After adjusting for the imbalance parameters,PDAC showed higher dimethyl sulfide levels than the control and IPMN groups,with adjusted odds ratio(aOR)of 6.98(95%CI:1.15-42.17)and 4.56(1.03-20.20),respectively(P<0.05 both).Acetone dimer levels were also higher in PDAC compared to controls and IPMN(aOR:5.12(1.80-14.57)and aOR:3.35(1.47-7.63),respectively(P<0.05 both).Acetone dimer,but not dimethyl sulfide,performed better than CA19-9 in PDAC diagnosis(AUROC 0.910 vs 0.796).The AUROC of acetone dimer increased to 0.936 when combined with CA19-9,which was better than CA19-9 alone(P<0.05).CONCLUSION Dimethyl sulfide and acetone dimer are VOCs that potentially distinguish PDAC from IPMN and healthy participants.Additional prospective studies are required to validate these findings. 展开更多
关键词 Volatile organic compound PANCREAS ADENOCARCINOMA Pancreatic intraductal neoplasms breathing
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Urea breath test for Helicobacter pylori infection in adult dyspeptic patients: A meta-analysis of diagnostic test accuracy
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作者 Fabian Fellipe Bueno Lemos Caroline Tianeze de Castro +9 位作者 Marcel Silva Luz Gabriel Reis Rocha Gabriel Lima Correa Santos Luís Guilherme de Oliveira Silva Mariana Santos Calmon Cláudio Lima Souza Ana Carla Zarpelon-Schutz Kádima Nayara Teixeira Dulciene Maria de Magalhães Queiroz Fabrício Freire de Melo 《World Journal of Gastroenterology》 SCIE CAS 2024年第6期579-598,共20页
BACKGROUND Helicobacter pylori(H.pylori)infection has been well-established as a significant risk factor for several gastrointestinal disorders.The urea breath test(UBT)has emerged as a leading non-invasive method for... BACKGROUND Helicobacter pylori(H.pylori)infection has been well-established as a significant risk factor for several gastrointestinal disorders.The urea breath test(UBT)has emerged as a leading non-invasive method for detecting H.pylori.Despite numerous studies confirming its substantial accuracy,the reliability of UBT results is often compromised by inherent limitations.These findings underscore the need for a rigorous statistical synthesis to clarify and reconcile the diagnostic accuracy of the UBT for the diagnosis of H.pylori infection.AIM To determine and compare the diagnostic accuracy of 13C-UBT and 14C-UBT for H.pylori infection in adult patients with dyspepsia.METHODS We conducted an independent search of the PubMed/MEDLINE,EMBASE,and Cochrane Central databases until April 2022.Our search included diagnostic accuracy studies that evaluated at least one of the index tests(^(13)C-UBT or ^(14)C-UBT)against a reference standard.We used the QUADAS-2 tool to assess the methodo-logical quality of the studies.We utilized the bivariate random-effects model to calculate sensitivity,specificity,positive and negative test likelihood ratios(LR+and LR-),as well as the diagnostic odds ratio(DOR),and their 95%confidence intervals.We conducted subgroup analyses based on urea dosing,time after urea administration,and assessment technique.To investigate a possible threshold effect,we conducted Spearman correlation analysis,and we generated summary receiver operating characteristic(SROC)curves to assess heterogeneity.Finally,we visually inspected a funnel plot and used Egger’s test to evaluate publication bias.endorsing both as reliable diagnostic tools in clinical practice.CONCLUSION In summary,our study has demonstrated that ^(13)C-UBT has been found to outperform the ^(14)C-UBT,making it the preferred diagnostic approach.Additionally,our results emphasize the significance of carefully considering urea dosage,assessment timing,and measurement techniques for both tests to enhance diagnostic precision.Nevertheless,it is crucial for researchers and clinicians to evaluate the strengths and limitations of our findings before implementing them in practice. 展开更多
关键词 Helicobacter pylori Urea breath test DIAGNOSIS Diagnostic test accuracy META-ANALYSIS
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Generation of breathing solitons in the propagation and interactions of Airy–Gaussian beams in a cubic–quintic nonlinear medium 被引量:4
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作者 陈卫军 鞠莹 +2 位作者 刘春阳 王连锴 卢克清 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第11期528-533,共6页
Using the split-step Fourier transform method, we numerically investigate the generation of breathing solitons in the propagation and interactions of Airy–Gaussian(AiG) beams in a cubic–quintic nonlinear medium in... Using the split-step Fourier transform method, we numerically investigate the generation of breathing solitons in the propagation and interactions of Airy–Gaussian(AiG) beams in a cubic–quintic nonlinear medium in one transverse dimension. We show that the propagation of single AiG beams can generate stable breathing solitons that do not accelerate within a certain initial power range. The propagation direction of these breathing solitons can be controlled by introducing a launch angle to the incident AiG beams. When two AiG beams accelerated in opposite directions interact with each other,different breathing solitons and soliton pairs are observed by adjusting the phase shift, the beam interval, the amplitudes,and the light field distribution of the initial AiG beams. 展开更多
关键词 cubic-quintic nonlinear medium Airy-Gaussian beams propagation and interactions breathing solitons
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Device-guided breathing exercises for the treatment of hypertension: An overview 被引量:2
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作者 Kornelis JJ van Hateren Gijs WD Landman +2 位作者 Susan JJ Logtenberg Henk JG Bilo Nanne Kleefstra 《World Journal of Cardiology》 CAS 2014年第5期277-282,共6页
The American Heart Association considers device-guided breathing as a reasonable treatment modality in their statement on non-pharmacological options for lowering blood pressure. This review discusses all randomized c... The American Heart Association considers device-guided breathing as a reasonable treatment modality in their statement on non-pharmacological options for lowering blood pressure. This review discusses all randomized controlled trials that have investigated the effects of device-guided breathing on blood pressure in patients with hypertension. Thirteen studies were included in this review. In total, 627 patients were in-cluded, of which 365 patients were allocated to device-guided breathing. Only 6 studies used acceptable control groups: listening to music, meditative relaxa-tion exercises, or a sham-device. Two sponsored trials showed beneficial effects of device-guided breathing, both used listening to music as a control group. The remaining 4 studies, which had no employees of the manufacturer listed as co-author, observed no benefi-cial effects on blood pressure. There is only 1 study that used a sham device as a control group. All other studies were to some extend methodologically flawed. Based on the studies with an acceptable methodologi-cal quality, there is no clear evidence supporting a short-term beneficial effect on blood pressure by using device-guided breathing. 展开更多
关键词 HYPERTENSION Device-guided breathing Review
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Sleep disordered breathing in interstitial lung disease: A review 被引量:2
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作者 Lauren K Troy Tamera J Corte 《World Journal of Clinical Cases》 SCIE 2014年第12期828-834,共7页
Patients with interstitial lung disease commonly exhibit abnormal sleep architecture and increased sleep fragmentation on polysomnography. Fatigue is a frequent complaint, and it is likely that poor sleep quality is a... Patients with interstitial lung disease commonly exhibit abnormal sleep architecture and increased sleep fragmentation on polysomnography. Fatigue is a frequent complaint, and it is likely that poor sleep quality is a significant contributor. A number of studies have shown that sleep disordered breathing is prevalent in this population, particularly in the idiopathic pulmonary fibrosis subgroup. The factors that predispose these patients to obstructive sleep apnoea are not well understood, however it is believed that reduced caudal traction on the upper airway can enhance collapsibility. Ventilatory control system instability may also be an important factor, particularly in those with increased chemo-responsiveness, and in hypoxic conditions. Transient, repetitive nocturnal oxygen desaturation is frequently observed in interstitial lung disease, both with and without associated obstructive apnoeas. There is increasing evidence that sleep-desaturation is associated with increased mortality, and may be important in the pathogenesis of pulmonary hypertension in this population. 展开更多
关键词 SLEEP DISORDERED breathing INTERSTITIAL lung disease Pulmonary fibrosis NOCTURNAL hypoxia OBSTRUCTIVE SLEEP APNOEA
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Explicit solution of the radial breathing mode frequency of single-wailed carbon nanotubes 被引量:5
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作者 Tienchong Chang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2007年第2期159-162,共4页
On the basis of a molecular mechanics model, an analytical solution of the radial breathing mode (RBM) frequency of single-walled carbon nanotubes (SWCNTs) is obtained. The effects of tube chirality and tube diame... On the basis of a molecular mechanics model, an analytical solution of the radial breathing mode (RBM) frequency of single-walled carbon nanotubes (SWCNTs) is obtained. The effects of tube chirality and tube diameter on the RBM frequency are investigated and good agreement between the present results and existing data is found. The present analytical formula indicates that the chirality and size dependent elastic properties are responsible for the effects of the chirality and small size on the RBM frequency of an SWCNT. 展开更多
关键词 Carbon nanotubes.Radial breathing mode . Molecular mechanics
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Exact breathing soliton solutions in combined time-dependent harmonic-lattice potential 被引量:1
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作者 佑六云 李画眉 何俊荣 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第3期153-158,共6页
We investigate the explicit novel localized nonlinear matter waves of the cubic-quintic nonlinear Schr6dinger equation with spafiotemporal modulation of the nonlinearities and the harmonic-lattice potential using a mo... We investigate the explicit novel localized nonlinear matter waves of the cubic-quintic nonlinear Schr6dinger equation with spafiotemporal modulation of the nonlinearities and the harmonic-lattice potential using a modified similarity trans- formation. We also find that when the modulus of the Jacobian elliptic function in the limit closes to 1, the shapes of the breathing solitons may exhibit some interesting features, i.e., one breathing soliton dividing into two in the ground state. The stability of the exact solutions is investigated numerically such that some stable breathing soliton solutions are found. 展开更多
关键词 breathing soliton cubic-quintic nonlinearity harmonic-lattice potential
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A semi-analytical approach for calculating the equilibrium structure and radial breathing mode frequency of single-walled carbon nanotubes 被引量:1
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作者 J.Gong L.Thompson G.Li 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2016年第6期1075-1087,共13页
A semi-analytical model for determining the equilibrium configuration and the radial breathing mode (RBM) frequency of single-wall carbon nanotubes (CNTs) is presented. By taking advantage of the symmetry characterist... A semi-analytical model for determining the equilibrium configuration and the radial breathing mode (RBM) frequency of single-wall carbon nanotubes (CNTs) is presented. By taking advantage of the symmetry characteristics, a CNT structure is represented by five independent variables. A line search optimization procedure is employed to determine the equilibrium values of these variables by minimizing the potential energy. With the equilibrium configuration obtained, the semi-analytical model enables an efficient calculation of the RBM frequency of the CNTs. The radius and radial breathing mode frequency results obtained from the semi-analytical approach are compared with those from molecular dynamics (MD) and ab initio calculations. The results demonstrate that the semi-analytical approach offers an efficient and accurate way to determine the equilibrium structure and radial breathing mode frequency of CNTs. 展开更多
关键词 Carbon nanotubes Equilibrium structure Radial breathing mode frequency
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Nonlinear Dynamic Characteristics of a Simple Blade with Breathing Crack Using Ansys Software 被引量:2
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作者 Salwan Obeed Waheed Nawras Haidar Mostafa Dhyai Hassan Jawad 《World Journal of Mechanics》 2011年第2期21-30,共10页
Nonlinear dynamic response represents the most important studies for structures subjected to a dynamic mo-tion so that it provides the researcher by an excellent information especially at critical design levels. The u... Nonlinear dynamic response represents the most important studies for structures subjected to a dynamic mo-tion so that it provides the researcher by an excellent information especially at critical design levels. The un-predictable nonlinearity in the structure appears when damage is inherited. Most times, the failure of the structure is related to the dynamic nonlinearity. With regard to the breathing phenomena for nonlinear struc-tural systems, very little is known about how the nonlinearities influence the response and the dynamic char-acteristics of cracked structures. In this research, dynamic nonlinearity is presented in damaged structure due to presence of a crack. The crack is assumed to be open and close simultaneously and then breathing. Effect of breathing phenomenon was studied deeply. Crack breathing is simulated at the crack surfaces using con-tact elements. The contact, geometrical, penalty, and spin stiffnesses are taken in consideration. In addition, effect of several important parameters such as rotor angular velocity and crack ratio are studied. The study showed that the breathing natural frequency of any structure is ranged between opened (no contact) and closed crack natural frequencies. The larger crack length, the more nonlinear disturbance in the dynamic re-sponse behavior. Also, at a critical crack length, some mode shapes tend to exchange and pass over with other modes. The presence of the mode interchanging and mode crossover was a guide on the nonlinear re-sponse for the cracked structure. The numerical modeling is achieved using ANSYS finite element program. Experimental data are used for validating the accurate use of contact elements in ANSYS environment. 展开更多
关键词 Nonlinear DYNAMICS breathing PHENOMENA Cracked BLADE CONTACT ANSYS
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The Complex Magnetism in the Breathing Pyrochlore LiIn(Cr_(1-x)Rh_x)_4O_8 被引量:1
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作者 王冬逸 谭程 +1 位作者 Kevin Huang 殳蕾 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第12期129-132,共4页
We perform a detailed investigation of the new 'breathing' pyrochlore compound LiInCr4O8 through Rh substi- tution with measurements of magnetic susceptibility, specific heat, and x-ray powder diffraction. The antif... We perform a detailed investigation of the new 'breathing' pyrochlore compound LiInCr4O8 through Rh substi- tution with measurements of magnetic susceptibility, specific heat, and x-ray powder diffraction. The antiferro- magnetic phase of LiInCr4O8 is found to be slowly suppressed with increasing Rh, up to the critical concentration of x = 0.1 where the antiferromagnetic phase is still observed with the peak in specific heat Tp = 12.5 K, slightly lower than Tp =14.3 K for the x = 0 compound. From tile measurements of magnetization we also uncover evidence that substitution increases the amount of frustration. Comparisons are made with the LiGayIn1-yCr4O8 system as well as other frustrated pyrochlore-related materials and comparable amounts of frustration are found. The results of this work show that the engineered breathing pyrochlores present an important method to further understand the complex magnetism in frustrated systems. 展开更多
关键词 RH is for in of x)Rh_x The Complex Magnetism in the breathing Pyrochlore LiIn Cr
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Comparing the rhythm and frequency of heart,breathing and knee movement in Tai Chi Chuan
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作者 魏珊珊 刘宇 李立 《医用生物力学》 EI CAS CSCD 2009年第S1期150-151,共2页
Background:The basic exercise involved in TCC is a series of individual movements that are linked together in a continuous manner and that flow smoothly from one movement to another.Deep breathing and mental concentra... Background:The basic exercise involved in TCC is a series of individual movements that are linked together in a continuous manner and that flow smoothly from one movement to another.Deep breathing and mental concentration are also required to achieve harmony 展开更多
关键词 Comparing the rhythm and frequency of heart breathing and knee movement in Tai Chi Chuan
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Association of breastfeeding with tidal breathing analysis in infants with bronchiolitis 被引量:2
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作者 Evanthia Perikleous Sotirios Fouzas +5 位作者 Athina Karageorgiou Paschalis Steiropoulos Evangelia Nena Athanasios Chatzimichael Aggelos Tsalkidis Emmanouil Paraskakis 《World Journal of Clinical Pediatrics》 2021年第6期168-176,共9页
BACKGROUND Tidal breathing flow-volume(TBFV)analysis provides important information about lung mechanics in infants.AIM To assess the effects of breastfeeding on the TBFV measurements of infants who recover from acute... BACKGROUND Tidal breathing flow-volume(TBFV)analysis provides important information about lung mechanics in infants.AIM To assess the effects of breastfeeding on the TBFV measurements of infants who recover from acute bronchiolitis.METHODS In this cross-sectional study,TBFV analysis was performed in infants with bronchiolitis prior to hospital discharge.The ratio of time to peak expiratory flow to total expiratory time(tPEF/tE)at baseline and after the administration of 400 mcg salbutamol was evaluated.RESULTS A total of 56 infants(35 boys),aged 7.4±2.8 mo,were included.Of them,12.5%were exposed to tobacco smoke and 41.1%were breastfed less than 2 mo.There were no differences in baseline TBFV measurements between the breastfeeding groups;however,those who breastfed longer than 2 mo had a greater change in tPEF/tE after bronchodilation(12%±10.4%vs 0.9%±7.1%;P<0.001).Moreover,there was a clear dose-response relationship between tPEF/tE reversibility and duration of breastfeeding(P<0.001).In multivariate regression analysis,infants who breastfed less(regression coefficient-0.335,P=0.010)or were exposed to cigarette smoke(regression coefficient 0.353,P=0.007)showed a greater change in tPEF/tE after bronchodilation,independent of sex,prematurity,and family history of asthma or atopy.CONCLUSION Infants who recover from bronchiolitis and have a shorter duration of breastfeeding or are exposed to cigarette smoke,have TBFV measurements indicative of obstructive lung disease. 展开更多
关键词 Tidal breathing analysis Lung function BRONCHIOLITIS BREASTFEEDING Cigarette smoke INFANTS
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