OBJECTIVETo measure the energy expenditure of reading and watching TV for young women.

METHODSAll 30 girls in the college were selected according to questionnaire, medical examination, blood test, liver function and thyroid gland level. Energy expenditure of reading and watching TV was measured respectively by the Cosmid K4b2 portable gas analysis system from Italy. Basic metabolic rate (BMR) and resting metabolic rate (RMR) were measured as to analyzing results conveniently.

RESULTSThe energy expenditure in reading was (226.35 +/- 56.07) kJ/h and the heart rate was (69 +/- 5) bmp. For watching TV it was (220.79 +/- 65.69) kJ/h and the heart rate was (68 +/- 5) bmp. BMR was (178.53 +/- 53.51) kJ/h and the heart rate was (62 +/- 6) bmp. RMR was (214.76 +/- 44.56) kJ/h and the heart rate was (65 +/- 6) bpm.

CONCLUSIONSThe energy expenditure in reading should be higher than that of watching TV, however, the difference was not obvious. The expenditure rates might get closer to those of RMR. It might be regarded as an expenditure of very light physical active in Chinese.

Adolescent ; Adult ; Basal Metabolism ; Female ; Humans ; Reading ; Rest ; physiology ; Television

Vigilance is defined as the ability to maintain attention or alertness over prolonged periods of time. Since Mid-20th century, following the increasing man-machine communication, high level of vigilance has been demanded in many areas including driving safety, medical care and therapy, aerospace and military affairs, etc. Therefore, finding quick methods to improve the level of vigilance has become a key issue in medical study. Based on physical regulation, chemical regulation and physiological regulation, the research progress has been summarized in this paper. We, furthermore, also try to predict the future trend in this academic area and develop some tentative ideas about seeking more effective and convenient ways to improve the level of brain vigilance.
Arousal ; physiology ; Attention ; Brain ; physiology ; Coffee ; Humans ; Light ; Rest ; physiology ; Sound

OBJECTIVETo assess functional relationship by calculating inter- and intra-hemispheric electroencephalography (EEG) coherence at rest and during a working memory task of patients with mild cognitive impairment (MCI).

METHODSThe sample consisted of 69 subjects: 35 patients (n=17 males, n=18 females; 52-71 years old) and 34 normal controls (n=17 males, n=17 females; 51~63 years old). Mini-mental state examination (MMSE) of two groups revealed that the scores of MCI patients did not differ significantly from those of normal controls (P>0.05). In EEG recording, subjects were performed at rest and during working memory task. EEG signals from F3-F4, C3-C4, P3-P4, T5-T6 and O1-O2 electrode pairs are resulted from the inter-hemispheric action, and EEG signals from F3-C3, F4-C4, C3-P3, C4-P4, P3-O1, P4-O2, T5-C3, T6-C4, T5-P3 and T6-P4 electrode pairs are resulted from the intra-hemispheric action for delta (1.0-3.5 Hz), theta (4.0-7.5 Hz), alpha-1 (8.0-10.0 Hz), alpha-2 (10.5-13.0 Hz), beta-1 (13.5-18.0 Hz) and beta-2 (18.5-30.0 Hz) frequency bands. The influence of inter- and intra-hemispheric coherence on EEG activity with eyes closed was examined using fast Fourier transformation from the 16 sampled channels.

RESULTSDuring working memory tasks, the inter- and intra-hemispheric EEG coherences in all bands were significantly higher in the MCI group in comparison with those in the control group (P<0.05). However, there was no significant difference in inter- and intra-hemispheric EEG coherences between two groups at rest.

CONCLUSIONExperimental results comprise evidence that MCI patients have higher degree of functional connectivity between hemispheres and in hemispheres during working condition. It suggests that MCI may be associated with compensatory processes during working memory tasks between hemispheres and in hemispheres. Moreover, failure of normal cortical connections may exist in MCI patients.

Aged ; Cognition Disorders ; physiopathology ; Electrodes ; Electroencephalography ; Female ; Humans ; Male ; Memory ; physiology ; Middle Aged ; Rest ; physiology

OBJECTIVETo study the changes in cardiopulmonary function induced by mid/long-term simulated microgravity with 6° head down bed rest (HDBR), and the effects of Taikong Yangxin Prescription (, TYP) as a countermeasure.

METHODSFourteen healthy male volunteers were randomly divided into a control group and a Chinese medicine (CM) group (7 in each group) by a random digital table based on their body weight. Both groups underwent 6° HDBR for 60 days. Subjects in the CM group received daily TYP pills and subjects in the control group received daily placebo pills. Cardiac systolic and pumping functions were measured by echocardiography before HDBR; on days 20, 42, and 57 of HDBR; and on day 3 of recovery after HDBR (R+3). Cardiopulmonary functional reserve and exercise capacity were evaluated before HDBR, on day 29, and on day R+3 by exercise testing.

RESULTSThe heart rate (HR) increased gradually during HDBR. The HR was significantly higher on day 57 than before HDBR in the control group (P<0.05), but did not increase significantly in the CM group. The stroke volume/stroke volume index, ejection fraction, and left ventricular fractional shortening tended to decrease over time in the control group, but not in the CM group. These parameters were significantly higher in the CM group than in the control group on day 42 (P<0.05 or <0.01). Exercise testing showed that maximum O2 consumption (VO2max), metabolic equivalents, relative O2 consumption (VO2), O2 pulse, and exercise duration were significantly lower on day 29 than before HDBR in the control group, but not in the CM group.

CONCLUSIONSSixty days of 6° HDBR induced a reduction in cardiac systolic and pumping functions, and reduced cardiopulmonary functional reserve and exercise capacity. Administration of TYP significantly improved cardiac systolic and pumping functions, and maintained cardiopulmonary functional reserve and exercise capacity.

Adult ; Bed Rest ; Drugs, Chinese Herbal ; Exercise Test ; Heart ; physiology ; Humans ; Lung ; physiology ; Male

The membrane permeability to potassium at a resting state is greater than to any other ions and the maintenance of resting membrane potential is largely dependent on K+ concentration of outside medium (Hodgkin and Horowicz 1959), i.e. an increase of K+ concentration of medium induces a depolarization, vice versa. However, on the contrary to this prediction, in some mammalian heart muscle a reduction of external K+ concentration induces a depolarization of membrane potential rather than a hyperpolarization (Vassalle 1965). In this study it was aimed to elucidate the possible mechanism of spontaneous depolarization induced by low external K+ in canine Purkinje fibers. The membrane potential was constantly recorded while components of cations in the bathing medium were replaced one by one by equimolar sucrose until the low K+ induced depolarization was blocked. The results are summarized as follows; The membrane potential of canine Purkinje fibers was spontaneously depolarized by low external K+, and the magnitude of depolarization was not affected by verapamil TEA, and a partial replacement of external Na+ and Ca2+ with choline chloride. But the membrane potential was hyperpolarized only when the all external cations were substitued with sucrose; and this hyperpolarization was disappeared again by substitution of sucrose with choline chloride. From these results, it may be concluded that the depolarization induced by low external K+ in canine Purkinje fibers is due to the nonspecific increase of membrane permeability to external cations and/or combinations with decreased K+ conductance.
Animal ; Dogs ; Guinea Pigs ; Heart/physiology* ; Membrane Potentials/drug effects* ; Papillary Muscles/physiology ; Potassium/pharmacology* ; Purkinje Fibers/physiology ; Rest

OBJECTIVETo investigate the recovery duration of manual lifting tasks.

METHODS30 college student volunteers with gender equally distributed were involved in the simulated stoop-, squart- and semi squart-lifting tasks in the laboratory. Signals of electromyography (EMG) at the back muscles (left and right thorax m. erector spinae, LT(10) and RT(10); left and right lumbar m. erector spinae, LL(3) and RL(3)) and electrocardiography (ECG) were recorded during the rest intervals. The percentage of maximum voluntary electrical activation (MVE%), EMG median frequency (MF), and heart rate (HR) were analyzed to predict the recovery time required.

RESULTSDuring the break, MVE% at 4 back muscles of all the male subjects were recovered to resting level within 5 minutes and 91.8% were within 2 minutes. Except for RL(3) after squat- and stoop-lifting task, the MVE% of female subjects went back to resting level within 3 minutes and 67.8% were within 2 minutes. The MF of male subjects were recovered in 10 minutes and 74.9% within 2 minutes, with the exception of RL(3) after stoop- and squat-lifting tasks. All the female MF were recovered in 8 minutes and 83.4% were within 2 minutes. However, during the last 20 minute break after the lifting tasks, the MVE% and MF of all male and female subjects were recovered, while HR came back to resting level within 14 and 5 minutes, respectively.

CONCLUSIONSFor the three manual lifting tasks with 25% MVC workload lasting for 4.5 min, a break of 15 minutes is sufficient for most erectors spinae to recover from local muscle load. However, in terms of the HR, a break of 15 minutes is enough for the recovery of systematic load.

Adult ; Back ; Electrocardiography ; Electromyography ; Female ; Humans ; Lifting ; Lumbosacral Region ; Male ; Muscle, Skeletal ; physiology ; Posture ; Rest ; physiology ; Weight-Bearing ; Young Adult

OBJECTIVE: Resting-state networks (RSNs), including the default mode network (DMN), have been considered as markers of brain status such as consciousness, developmental change, and treatment effects. The consistency of functional connectivity among RSNs has not been fully explored, especially among resting-state-related independent components (RSICs). MATERIALS AND METHODS: This resting-state fMRI study addressed the consistency of functional connectivity among RSICs as well as their spatial consistency between 'at day 1' and 'after 4 weeks' in 13 healthy volunteers. RESULTS: We found that most RSICs, especially the DMN, are reproducible across time, whereas some RSICs were variable in either their spatial characteristics or their functional connectivity. Relatively low spatial consistency was found in the basal ganglia, a parietal region of left frontoparietal network, and the supplementary motor area. The functional connectivity between two independent components, the bilateral angular/supramarginal gyri/intraparietal lobule and bilateral middle temporal/occipital gyri, was decreased across time regardless of the correlation analysis method employed, (Pearson's or partial correlation). CONCLUSION: RSICs showing variable consistency are different between spatial characteristics and functional connectivity. To understand the brain as a dynamic network, we recommend further investigation of both changes in the activation of specific regions and the modulation of functional connectivity in the brain network.
Brain/*physiology ; Brain Mapping ; Humans ; Image Processing, Computer-Assisted ; Magnetic Resonance Imaging/*methods ; Male ; Neural Pathways/*physiology ; Regression Analysis ; Rest/*physiology ; Young Adult

OBJECTIVETo investigate if heart rate variability (HRV) can be used to evaluate mental workload.

METHODSForty-six volunteers were selected to simulate mental work by inputting the random number through keyboards. ECG was recorded by Holter 8800 during the performance and transferred into digital signal. Total power (TP), low frequency (LF), high frequency (HF) were analysed by Holter software.

RESULTSAlong with time, the inputting speed increased but accuracy decreased, and was positively correlated with TP, LF (r = 0.851 and 0.827 respectively, P < 0.05), showing a distinct dose-effect relationship. HRV values at rest were higher than during mental work [TP: (2 745.4 +/- 1 301.6) vs (686.2 +/- 420.7) ms(2)/Hz; HF: (670.6 +/- 393.8) vs (202.6 +/- 171.7) ms(2)/Hz; LF: (870.5 +/- 553.7) vs (206.0 +/- 187.9) ms(2)/Hz] indicating that they were decreased remarkably as the mental work started. Then, they were gradually increased with the workload (intensity and time) increased, but still at lower level.

CONCLUSIONHRV may be used as a parameter to evaluate mental workload but the change pattern of HRV needs to study further.

Adult ; Electrocardiography, Ambulatory ; statistics & numerical data ; Evaluation Studies as Topic ; Female ; Heart Rate ; physiology ; Humans ; Male ; Mental Processes ; physiology ; Rest ; physiology ; Workload

PURPOSE: In this study rest-activity rhythm, sleep pattern and quality of life of patients with restless legs syndrome were compared with those of a normal group. METHODS: The participants in this study were 36 patients with restless legs syndrome diagnosed by a neurologist and 36 participants in the normal group. An actigraph, sleep diary, Pittsburgh Sleep Quality Index and Insomnia Severity Index scale were used as measurement tools for the study. Chi-square test, Lamda test, t-test and Kendall's correlation with SPSS 12.0 program were used to analyze the data. RESULTS: Patients with restless legs syndrome had a higher rest-activity rhythm curve of Least 5 hr's activity (L5) and Most 10 hr's activity (M10) than those of normal group and sleep problems included decreased sleep efficiency and increased sleep latency, wake time and number of awakenings. The scores for the subscales of quality of life in patients with restless legs syndrome were lower than the normal group for general health, physical functioning, role limitations due to emotional problems, role limitation due to physical problems, social functioning, bodily pain, vitality and mental health. CONCLUSION: The results suggest that further studies are needed to identify rest-activity rhythm according to symptom severity and to develop nursing interventions which consider rest-activity rhythm.
Adult ; Aged ; Data Interpretation, Statistical ; Female ; Humans ; Male ; Middle Aged ; *Quality of Life ; *Rest ; Restless Legs Syndrome/*psychology ; Severity of Illness Index ; Sleep/*physiology

OBJECTIVETo investigate the relationship between resting energy expenditure (REE) and patterns of obesity/regional fat parameters in Chinese adults.

METHODSBody mass index (BMI), fat mass (FM), fat-free mass (FFM) were assessed in 109 Chinese adults (52 men and 57 women), and their abdominal visceral adipose tissue area (VA) and subcutaneous fat area (SA) were measured using magnetic resonance imaging (MRI) measurements. REE was measured with indirect calorimetry and compared with normal and obese subjects. Multivariate analysis was used to study the factors related to REE.

RESULTSThe resting energy expenditure per kilogram of body weight (REE/kg) was closely related with the area of abdominal visceral fat measured with MRI. REE/kg was significantly lower in overweight/obesity subjects than in normal-weighted subjects, and significantly lower in subjects with abdominal obesity (VA > or = 100 cm2) than in subjects with non-abdominal obesity (VA < 100 cm2, BMI > or = 25 kg/m2). In the stepwise regression analysis of REE/kg on regional fat parameters, VA in men and women and SA in women were independent factors reversely related to REE/kg.

CONCLUSIONREE/kg is associated with the visceral fat area and more prominent in men. REE/kg can be used as an index in the pathophysiology of intra-abdominal obesity.

Adipose Tissue ; metabolism ; Body Composition ; Body Mass Index ; Body Weight ; Energy Metabolism ; Fats ; metabolism ; Female ; Humans ; Male ; Middle Aged ; Obesity ; metabolism ; Rest ; physiology ; Viscera ; metabolism