• 대한의용생체공학회:의공학회지
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• 제11권2호
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• pp.195-202
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• 1990

The hypothesis of asymmetric resistance to explain the phenomenon of lung hyperinflation (LHI) during hlgh frequency ventilation (HFV) was quantitatively studied. LHI was predicted by modeling the ism-volume pressure-flow (IVPF) data from 5 human subjects using the empirical Rohrer's equation. Non-steadiness during HFV was compensated by em- ploying recently proposed volume-frequency diagram. Tidal volume and ventilation frequency were 100 ml and 20 Hz, respectively. Airflow pattern was a symmetric sinusoid. The predic- tion results of mean pressure drop across the airways were averaged for those 5 subjects, and compared with zero by one-sided student's t-test. A marginally significant (P<0.1) increase in mean pressure drop was observed during HFV at low lung volumes (below FRC) , which could increase mean lung volume up to one liter When the lung volume was above FRC, no significant LHI (P >0.25) was resulted. LHI seemed to be inversely related to the lung volume. These results recommend to clinically apply HFV only at lung volumes above FRC.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2007년도 하계종합학술대회 논문집
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• pp.279-280
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• 2007

Airway wall thickness is an important bio-marker for evaluation of pulmonary diseases such as stenosis, bronchiectasis. Nevertheless, an image-based analysis of the airway tree can provide precise and valuable airway size information, quantitative measurement of airway wall thickness in CT images involves various sources of error and uncertainty. So we have developed an accurate airway wall measurement technique for small airways with three-dimensional (3-D) approach. To illustrate performance of these techniques, we used airway phantom that consisted of 4 acryl tubes with various inner and outer diameters. Results show that evaluation of interpolation and deconvolution methods of airways in 3-D CT images, and significant improvement over the full-width-half-maximum method for measurement of not only location of the luminal and outer edge of the airway wall but airway wall thickness.

• 수완나부미
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• 제12권2호
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• pp.225-244
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• 2020

Area Studies, by definition, conjure ideas of emplaced knowledge; in-depth interdisciplinary understanding of language, history, culture and politics of a nation or region. Where detractors might see this approach as overly empirical, therefore precluding theoretical sophistication, others argue that "places" are either artificially constructed, or that processes of globalisation have obliterated the cultural zone. But what if we turn an ethnographic eye to those very processes and technologies themselves? Can Area Studies take to the air, and if so, what are the attendant challenges and benefits? Based on insights from ethnography amongst airline customer service workers, ground and cabin crews in Thailand and Myanmar, this research examines the airline cabin as a field for ethnographic study, and as an emplaced site for political and cultural processes. With participant observation-based knowledge of Southeast Asian cabin crews, this paper examines the 1990 hijack of Thai Airways TG 305 from an emplaced cultural perspective.

• Journal of Preventive Medicine and Public Health
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• 제47권1호
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• pp.57-63
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• 2014

Objectives: We established a Wistar rat model of asthma caused by toluene diisocyanate (TDI) exposure, and investigated the relationship between TDI exposure concentrations and respiratory hypersensitivity, airway inflammation, and cytokine secretions in animals, to better understand the mechanism of TDI induced occupational asthma. Methods: Wistar rats were exposed to two different concentrations of TDI vapor four hours a day for five consecutive days. Bronchoalveolar lavage (BAL) was performed, and differential leucocytes from the BAL fluid were analyzed. Lung histopathological examination was carried out to investigate the inflammatory status in the airways. Production of cytokines interleukin (IL)-4 and IL-5 productions in the BAL fluid in vivo was determined with enzyme-linked immunosorbent assay kits. Results: The TDI-exposed rats exhibited greater airway hypersensitivity symptoms than the control rats. The BAL differential cell count and lung histopathological examination demonstrated that inflammation reactions were present in both the central and peripheral airways, characterized with marked infiltration of eosinophils in the TDI-exposed rats. The cytokine assay showed that IL-4 and IL-5 were predominantly produced in the BAL fluid in vivo. Conclusions: These findings imply that TDI exposure concentrations may greatly affect the occurrence and extent of inflammatory events and that Th2 type cytokines may play an important role in the immunopathogenesis of TDI-induced occupational respiratory hypersensitivity.

• The Korean Journal of Physiology and Pharmacology
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• 제16권1호
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• pp.59-64
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• 2012

Hypoxic pulmonary vasoconstriction (HPV) is physiologically important response for preventing mismatching between ventilation and perfusion in lungs. The HPV of isolated pulmonary arteries (HPV-PA) usually require a partial pretone by thromboxane agonist (U46619). Because the HPV of ventilated/perfused lungs (HPV-lung) can be triggered without pretone conditioning, we suspected that a putative tissue factor might be responsible for the pretone of HPV. Here we investigated whether HPV can be also observed in precision-cut lung slices (PCLS) from rats. The HPV in PCLS also required partial contraction by U46619. In addition, $K^+$ channel blockers (4AP and TEA) required U46619-pretone to induce significant contraction of PA in PCLS. In contrast, the airways in PCLS showed reversible contraction in response to the $K^+$ channel blockers without pretone conditioning. Also, the airways showed no hypoxic constriction but a relaxation under the partial pretone by U46619. The airways in PCLS showed reliable, concentration-dependent contraction by metacholine ($EC_{50}$, ~210 nM). In summary, the HPV in PCLS is more similar to isolated PA than V/P lungs. The metacholineinduced constriction of bronchioles suggested that the PLCS might be also useful for studying airway physiology in situ.

• Clinical and Experimental Pediatrics
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• 제45권7호
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• pp.875-883
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• 2002

목 적 : 기관지 천식은 Th2 반응 우세로 인한 기도의 호산구증과 IgE 증가를 특징으로 하는 질환이다. 박테리아 DNA 혹은 합성 ODNs인 unmethylated CpG motifs(CpG)은 Th1 사이토카인인 $INF-{\gamma}$와 IL-12 유도와 Th2 사이토카인을 하강 조절하여 기도 내의 호산구증 및 전신적 IgE 생성을 억제하며, 메타콜린 흡입에 의한 기관지 과민성을 방지한다. 저자들은 기도 염증을 유발한 생쥐의 비강내에 합성 CpG ODNs의 점적 투여로 기도의 호산구증과 그 외 면역학적 기전에 대한 영향을 연구하고자 한다. 방 법 : BALB/c 생쥐에 주당 2번씩 면역보강제 없이 OVA를 $10{\mu}g$을 피하 주사하여 감작 시켰다. 10주째에 $50{\mu}g$ OVA를 백서의 비강내로 주입하여 기도 염증을 유도한 후, 4주 뒤인 14주째 다시 생쥐의 비강내에 OVA＋CpG ODNs과 OVA를 점적 흡입 주입하였다. 마지막 항원 유발(14주) 후 4일째에 기관지 폐포 세척액을 추출하여 세포를 염색한 후 호산구를 측정하였고 동시에 비장 세포를 배양하여 사이토카인 측정을 하였다. 비장 세포에서 OVA에 의해 생성된 사이토카인 즉 Th1($INF-{\gamma}$, IL-12), Th2(IL-4, IL-5, IL-13) 사이토카인을 ELISA에 의해 측정하였다. 혈청 항원 특이 IgE, IgG2a 또한 ELISA에 의해 측정하였다. 결 과 : 1) 기관지폐포 세척액의 호중구수 : CpG ODNs을 투여한 군이 7.6[5.8-9.4]%, CpG ODNs을 투여하지 않은 군이 42.0[38.2-44.6]%로 기도 염증 세포내의 호산구증을 현저히 억제시켰다(P<0.01). 2) 혈청 OVA-specific IgE와 IgG2a : CpG ODNs으로 투여한 군과 투여하지 않은 군에서 측정한 혈청 OVA-specific IgE와 IgG2a는 음성 대조군에 비해 현저히 증가하였고, CpG ODNs을 비강내 투여 후 4일째 측정한 혈청 OVA-specific IgE와 IgG2a 수치는 CpG ODNs 투여군과 비투여군 사이에 유의한 차이가 없었다. 3) 사이토카인 분석 : CpG ODNs으로 투여한 군은 투여하지 않은 군에 비해 IL-4, IL-5, IL-13의 생성이 감소하였고 IL-12 생성은 증가하였으나, $INF-{\gamma}$의 상향조절은 보여주지 못하였다. 결 론: CpG ODNs의 백신 접종은 면역반응을 조절하여 기도 염증이 형성된 생쥐에서 기도 호산구증을 감소시키는데 매우 효과적이며 천식 치료에 유용할 수 있을 것으로 사료된다.

• Biomaterials and Biomechanics in Bioengineering
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• 제2권4호
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• pp.225-235
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• 2015

Treatments for asthma are largely pharmaceutical, with some therapies also utilising alternative breathing techniques. The objective of both medical and alternative methods is to relax contracted airway smooth muscle (ASM). In normal subjects, tidal breathing- and deep inspiration-oscillations are believed to have a bronchodilatory effect. Similarly, application of length oscillations to isolated, contracted ASM also elicits muscle relaxation. As a means of investigating more-effective alternative treatment methods for contracted airways, we analyse the combined effects of bronchodilators and length oscillations on isolated, contracted ASM. The contractile state of the muscle tissue prior to treatment is of primary interest. Thereafter, the effect of applying a combination of small superimposed length oscillations with tidal breathing-like oscillations to ASM is studied alone and in combination with a common bronchodilator, isoproterenol (ISO). This work suggests that relaxation of isolated, contracted ASM following application of combined oscillations and ISO is larger than treatments of either combined oscillations or ISO alone. Further, the observed oscillation-associated relaxation is found to be amplitude- rather than frequency-dependent. This study gives additional insight into the role of oscillations and bronchodilators on contracted airways.

• Journal of Dental Anesthesia and Pain Medicine
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• 제15권3호
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• pp.181-184
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• 2015

Airway difficulties are a major concern for anesthesiologists. Even though fiberoptic intubation is the generally accepted method for management of difficult airways, it is not without disadvantages-requires patient cooperation, and cannot be performed on soiled airway or upper airways with pre-existing narrowing pathology. Additionally, fiberoptic bronchoscopy is not available at every medical institution. In this case, we encountered difficult airway management in a 71-year-old man with a high Mallampati grade and a thick neck who had undergone urologic surgery. Several attempts, including a bronchoscope-guided intubation, were unsuccessful. Finally, blind nasal intubation was successful while the patient's neck was flexed and the tracheal cartilage was gently pressed down. We suggest that blind nasal intubation is a helpful alternative in difficult airway management and it can be a lifesaving technique in emergencies. Additionally, its simplicity makes it a less expensive option when advanced airway technology (fiberoptic bronchoscopy) is unavailable.

• 동의생리병리학회지
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• 제19권1호
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• pp.106-113
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• 2005

Asthma is an inflammatory disease of airways that is induced by Th2 cytokines and inhibited by Th1 cytokines. In this study we wanted to investigate the effect of SCT and BJT on eosinophilla and cytokines of BALF in a mouse model established airway inflammmation. Asthma was induced to male c57/bl6 mice. Allergen-specific antibody responses, cytokine$(IL-4,\;IL-5,\;INF-{\gamma})$, and eosinophil inflammation of the airways were investigated on the BALF and splenocyte. SCT and BJT effectively induced $INF-{\gamma}$ and inhibited IL-4, IL-5 as well as eosinophilic inflammation when SCT and BJT were administered. Total Ig E level in the BALF decreased. SCT was more effectiveness than BJT. It is considered that SCT and BJT have faborable effect on the asthma because the asthma specific series of abnormalities in respiratory system were decreased.

• The Journal of Asian Finance, Economics and Business
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• 제5권3호
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• pp.95-102
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• 2018

The objective of this research is to explore the diverse challenges faced by the customer as well transport providers through the selected modes of transportation of the second most populous country in the world - India. Two separate well-structured questionnaires administered to garner the opinions on different challenges. A random sample of 100 equally selected from the customers of 3 modes of transportation along with 30 transport providers. The collected data was analyzed in Microsoft Excel and R Studio platforms using Percentile Rank Tool and R Programming Language for Chi-square test respectively. Traffic congestion coupled with parking is the major problem in case of roadways while Safety and cleanliness in railways are the first amongst the problems to reckon with. High fares and lack of trained employees are the biggest challenges faced by aviation industry. The research is concentrated only in the states of Andhra Pradesh and Telangana in India with most widely used three modes of transportation viz., Road, Rail and Airways. This research paper is first of its kind which has collected the opinions of both customers as well transport providers on the problems faced. This research proffers information about the challenges faced by the customers which there will be an enormous possibility to review their strategies and plans.