• Geomechanics and Engineering
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• v.13 no.3
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• pp.489-504
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• 2017

The localized shear and the slip lines are easily observed in elastic-brittle-plastic rock. After yielding, the strength of the brittle rock suddenly drops from the peak value to the residual value, and there are slip lines which divide the macro rock into numbers of elements. There are slippages of elements along the slip lines and the displacement field in the plastic region is discontinuous. With some restraints, the discontinuities can be described by the combination of two smooth functions, one is for the meaning of averaging the original function, and the other is for characterizing the breaks of the original function. The slip lines around the circular opening in the plastic region of an isotropic H-B rock which subjected to a hydrostatic in situ stress can be described by the logarithmic spirals. After failure, the deformation mechanism of the plastic region is mainly attributed to the slippage, and a slippage parameter is introduced. A new analytical solution is presented for the plane strain analysis of displacements around circular openings. The displacements obtained by using the new solution are found to be well coincide with the exact solutions from the published sources.

• The Journal of Korean Physical Therapy
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• v.33 no.4
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• pp.179-186
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• 2021

Background: Patients with advanced asthma and chronic obstructive pulmonary disease (COPD) have postural deviations such as thoracic hyperkyphosis, forward shoulder posture (FSP) due to an increase in head and cervical protraction, reduced shoulder range of motion and a corresponding increase in scapula elevation and upward rotation. Unlike congenital vertebral kyphosis that are permanent and rigid deformities with bony and other structural deformations which cause respiratory impairment, these deformities in these patients may be more flexible. Since the thoracic hyperkyphosis has been implicated as having adverse health consequences it is necessary to evaluated the relationship between thoracic kyphosis and cardiopulmonary functions of patients with COPD and asthma. Methods: It was a cross-sectional analytical study. Eighty-four eligible patients with COPD and asthma were recruited from the Respiratory Unit, Department of Medicine, Lagos University Teaching Hospital (LUTH), and basic anthropometric parameters, pulmonary parameters, cardiovascular parameters, thoracic kyphosis (Cobb) angle and presence of respiratory symptoms of participants were assessed. Data was analyzed using SPSS version 20. Results: There was no significant correlation between the thoracic kyphosis and selected pulmonary parameters (Forced Expiratory Volume in one second (FEV1, p=0.36), Forced Vital Capacity (FVC, p=0.95), Peak Expiratory Flow Rate (PEFR, p=0.16), Thoracic expansion (TE, p=0.27)/cardiovascular parameters (Systolic Blood Pressure (SBP, p=0.108), Diastolic Blood Pressure (DBP, p=0.17) and Pulse Rate (PR, p=0.93) as well as the respiratory symptoms (SGRQ scores, p=0.11) in all subjects. Conclusion: There was no relationship between thoracic kyphosis and selected pulmonary/cardiovascular parameters as well as respiratory symptoms in patients with COPD and asthma.

• Coupled systems mechanics
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• v.8 no.2
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• pp.169-184
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• 2019

This research work presents a study that aims to assess the dynamic structural behaviour and also investigate the human comfort levels of a reinforced concrete building, when subjected to nondeterministic wind dynamic loadings, considering the effect of masonry infills on the global stiffness of the structural model. In general, the masonry fills most of the empty areas within the structural frames of the buildings. Although these masonry infills present structural stiffness, the common practice of engineers is to adopt them as static loads, disregarding the effect of the masonry infills on the global stiffness of the structural system. This way, in this study a numerical model based on sixteen-storey reinforced concrete building with 48 m high and dimensions of $14.20m{\times}15m$ was analysed. This way, static, modal and dynamic analyses were carried out in order to simulate the structural model based on two different strategies: no masonry infills and masonry infills simulated by shell finite elements. In this investigation, the wind action is considered as a nondeterministic process with unstable properties and also random characteristics. The fluctuating parcel of the wind is decomposed into a finite number of harmonic functions proportional to the structure resonant frequency with phase angles randomly determined. The nondeterministic dynamic analysis clearly demonstrates the relevance of a more realistic numerical modelling of the masonry infills, due to the modifications on the global structural stiffness of the building. The maximum displacements and peak accelerations values were reduced when the effect of the masonry infills (structural stiffness) were considered in the dynamic analysis. Finally, it can be concluded that the human comfort evaluation of the sixteen-storey reinforced concrete building can be altered in a favourable way to design.

• Journal of the Korean Geotechnical Society
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• v.34 no.11
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• pp.71-80
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• 2018

In this study, the seismic response of cut-and-cover box tunnels is evaluated from pseudo-static analyses and the fragility curves are derived. A series of site profiles were used to evaluate the effect of soil conditions. A total of 20 ground motions were used. The fragility curves were developed as functions of peak ground acceleration for three damage states, which are minor, moderate, and extensive states. The damage indices, defined as the ratio of the elastic moment to the yield moment, correlated to three damage states, were used. The curves are shown to greatly depend on the site profile. The curves are further compared to those derived in previous studies. The widely used empirically derived curves are shown not to account for the site effects, and therefore underestimate the response for soft sites.

• The Korean Journal of Physiology and Pharmacology
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• v.23 no.5
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• pp.419-426
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• 2019

Mosapride accelerates gastric emptying by acting on 5-hydroxytryptamine type 4 ($5-HT_4$) receptor and is frequently used in the treatment of gastrointestinal (GI) disorders requiring gastroprokinetic efficacy. We tested the effect of mosapride on 5-hydroxytryptamine type 3 ($5-HT_3$) receptor currents because the $5-HT_3$ receptors are also known to be expressed in the GI system and have an important role in the regulation of GI functions. Using the whole-cell voltage clamp method, we compared the currents of the $5-HT_3$ receptors when 5-HT was applied alone or was co-applied with mosapride in cultured NCB-20 cells known to express $5-HT_3$ receptors. The $5-HT_3$ receptor current amplitudes were inhibited by mosapride in a concentration-dependent manner. Mosapride blocked the peak currents evoked by the application of 5-HT in a competitive manner because the $EC_{50}$ shifted to the right without changing the maximal effect. The rise slopes of $5-HT_3$ receptor currents were decreased by mosapride. Pre-application of mosapride before co-application, augmented the inhibitory effect of mosapride, which suggests a closed channel blocking mechanism. Mosapride also blocked the opened $5-HT_3$ receptor because it inhibited the $5-HT_3$ receptor current in the middle of the application of 5-HT. It accelerated desensitization of the $5-HT_3$ receptor but did not change the recovery process from the receptor desensitization. There were no voltage-, or use-dependency in its blocking effects. These results suggest that mosapride inhibited the $5-HT_3$ receptor through a competitive blocking mechanism probably by binding to the receptor in closed state, which could be involved in the pharmacological effects of mosapride to treat GI disorders.

• Journal of The Korean Society of Integrative Medicine
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• v.8 no.4
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• pp.155-161
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• 2020

Purpose : This study was conducted to investigate the effect of positive active pressure technique and active breathing technique on lung function in healthy adults. Methods : In this study, the passive lung expansion technique and active respiration enhancement technique using an air mask bag unit were conducted in 30 normal adults to observe changes in pulmonary function with forced vital capacity (FVC), Forced expiratory volume at one second (FEV1). In order to observe the change in the level of respiratory function, we would like to investigate the peak expiratory flow (PEF) and the forced expiratory flow (FEF 25-75 %). Results : As a result of this study, there was no significant difference in comparison between the passive lung expansion technique and the active breathing enhancement technique (p>.05). The passive lung expansion technique effectively increased the effortful expiratory volume and the median expiratory flow rate of 1 second (p<.05). And the passive lung expansion technique effectively increased the effortless lung capacity and the maximum expiration flow rate (p<.05). Conclusion : The passive lung expansion technique effectively increases the range of motion of the lungs and chest cages, intrathoracic pressure, and elasticity of the lungs, and the active breathing technique increases the muscle functions such as the diaphragm and the biceps muscles. It is expected that it will be able to selectively improve the respiratory function of patients with respiratory diseases or functional limitations as it is found to be effective.

• The Journal of Korean Physical Therapy
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• v.35 no.4
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• pp.111-116
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• 2023

Purpose: Pneumoconiosis is a chronic lung disease in which the lungs become hardened due to the accumulation of fine mineral dust that has been breathed in at industrial sites. The lungs are unable to function properly, resulting in complications of several respiratory diseases. Methods: The subjects were 36 elderly adults (pneumoconiosis patients 18, healthy elderly 18) over the age of 65 years. The respiratory function was assessed using a spirometer to measure forced vital capacity (FVC), first second of forced expiration (FEV1), FEV1/FVC, and peak expiratory flow n(PEF). The static balance function test was determined by the center of mass (COM), ankle angle range, hip angle range, sway parameters, and reciprocal compensatory index (RCI). Cognitive function was measured by applying MoCA-k. Results: Comparison of respiration functions between the two groups showed statistically significant differences in FVC, FEV1, FEV1/FVC, and PEFs (p<0.05). Cognitive abilities showed statistically significant differences due to higher cognitive skills in the control group as compared to the patient group (p<0.05). Most results of the static balance capability measurements showed statistically significant differences between the groups (p<0.05). However, no statistically significant differences were obtained for COM AP Range, Angle AP Range, RCI ML Range, and AP Range (p>0.05). Conclusion: The results of the current study indicate that patients suffering from pneumoconiosis have less cognitive ability and balance function as compared to healthy elderly people. Therefore, we expect an improvement in the balance ability and cognitive function through systematic management and strengthening lung function training to improve the quality of life of pneumoconiosis patients.

• The Korean Journal of Physiology and Pharmacology
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• v.27 no.5
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• pp.481-491
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• 2023

The β subunits of high voltage-gated calcium channels (HGCCs) are essential for optimal channel functions such as channel gating, activation-inactivation kinetics, and trafficking to the membrane. In this study, we report for the first time the potent blood pressure-reducing effects of peptide fragments derived from the β subunits in anesthetized and non-anesthetized rats. Intravenous administration of 16-mer peptide fragments derived from the interacting regions of the β1 [cacb1(344-359)], β2 [cacb2(392-407)], β3 [cacb3(292-307)], and β4 [cacb4(333-348)] subunits with the main α-subunit of HGCC decreased arterial blood pressure in a dose-dependent manner for 5-8 min in anesthetized rats. In contrast, the peptides had no effect on the peak amplitudes of voltage-activated Ca²⁺ current upon their intracellular application into the acutely isolated trigeminal ganglion neurons. Further, a single mutated peptide of cacb1(344-359)-cacb1(344-359)_K357R-showed consistent and potent effects and was crippled by a two-amino acid-truncation at the N-terminal or C-terminal end. By conjugating palmitic acid with the second amino acid (lysine) of cacb1(344-359)_K357R (named K2-palm), we extended the blood pressure reduction to several hours without losing potency. This prolonged effect on the arterial blood pressure was also observed in non-anesthetized rats. On the other hand, the intrathecal administration of acetylated and amidated cacb1(344-359)_K357R peptide did not change acute nociceptive responses induced by the intradermal formalin injection in the plantar surface of rat hindpaw. Overall, these findings will be useful for developing antihypertensives.

• Journal of Biomedical Engineering Research
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• v.44 no.6
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• pp.377-383
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• 2023

Purpose: There is increasing attention to the application of transcranial direct current stimulation (tDCS) for enhancing cognitive functions in subjects to aging, mild cognitive impairment (MCI), and Alzheimer's disease (AD). Despite varying treatment outcomes in tDCS which depend on the amount of current reaching the brain, there is no general information on the impacts of anatomical features associated with AD on tDCS-induced electric field. Objective: The objective of this study is to examine how AD-related anatomical variation affects the tDCS-induced electric field using computational modeling. Methods: We collected 180 magnetic resonance images (MRI) of AD patients and healthy controls from a publicly available database (Alzheimer's Disease Neuroimaging Initiative; ADNI), and MRIs were divided into female-AD, male-AD, female-normal, and male-normal groups. For each group, segmented brain volumes (cerebrospinal fluid, gray matter, ventricle, rostral middle frontal (RMF), and hippocampus/amygdala complex) using MRI were measured, and tDCS-induced electric fields were simulated, targeting RMF. Results: For segmented brain volumes, significant sex differences were observed in the gray matter and RMF, and considerable disease differences were found in cerebrospinal fluid, ventricle, and hippocampus/amygdala complex. There were no differences in the tDCS-induced electric field among AD and normal groups; however, higher peak values of electric field were observed in the female group than the male group. Conclusions: Our findings demonstrated the presence of sex and disease differences in segmented brain volumes; however, this pattern differed in tDCS-induced electric field, resulting in significant sex differences only. Further studies, we will adjust the brain stimulation conditions to target the deep brain and examine the effects, because of significant differences in the ventricles and deep brain regions between AD and normal groups.

• Clinical and Experimental Vaccine Research
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• v.12 no.1
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• pp.32-46
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• 2023

Purpose: The present study aimed to compare the immune-enhancing potential of gold nanoparticles (AuNPs) to Alum against rabies vaccine and the related immunological, physiological, and histopathological effects. Materials and Methods: Alum and AuNPs sole and in combination with rabies vaccine were used at 0.35 mg/mL and 40 nM/mL, respectively. Rats used were categorized into six groups (20/each): control rats, rabies vaccine, aluminum phosphate gel, rabies vaccine adsorbed to Alum, AuNPs, and rabies vaccine adjuvant AuNPs. Results: Liver and kidney functions were in the normal range after AuNPs and Alum adjuvanted vaccine compared to control. Interleukin-6 and interferon-γ levels were significantly increased in groups immunized with Alum and AuNPs adjuvanted vaccine, the peak level was in the case of AuNP adjuvanted vaccine on the 14th day. Ninety days post-vaccination, total immunoglobulin G (IgG) against adjuvanted rabies vaccine showed a significantly elevated antirabies IgG with AuNPs and Alum adsorbed vaccine compared with unadjuvanted one. The total antioxidant capacity, malondialdehyde (MDA) levels, superoxide dismutase, and glutathione peroxidase activities were significantly increased post-adjuvanted AuNPs adjuvanted vaccine vaccination than in Alum adsorbed vaccine, while MDA was significantly decreased. The histopathological examination revealed detectable alterations post-AuNPs and Alum adjuvanted vaccine immunization compared with liver and kidney profiles post-administration of unadjuvanted and non-immunized groups, meanwhile, splenic tissue revealed hyperplasia of lymphoid follicles indicating increased immune reactivity. Conclusion: The AuNPs are promising enhancers of the immune response as Alum, and the undesirable effects of AuNPs could be managed by using suitable sizes, shapes, and concentrations.