• International Journal of Automotive Technology
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• v.8 no.4
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• pp.437-444
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• 2007

This paper experimentally investigates the effects of oxygen-enriched air (OEA) on the running behaviors of an LPG SI engine during both start/warm-up (SW) and hot idling (HI) stages. The experiments were performed on an air-cooled, single-cylinder, 4-stroke, LPG SI engine with an electronic fuel injection system and an electrically-heated oxygen sensor. OEA containing 23% and 25% oxygen (by volume) was supplied for the experiments. The throttle position was fixed at that of idle condition. A fueling strategy was used as following: the fuel injection pulse width (FIPW) in the first cycle of injection was set 5.05 ms, and 2.6 ms in the subsequent cycles till the achieving of closed-loop control. In closed-loop mode, the FIPW was adjusted by the ECU in terms of the oxygen sensor feedback. Instantaneous engine speed, cylinder pressure, engine-out time-resolved HC, CO and NOx emissions and excess air coefficient (EAC) were measured and compared to the intake air baseline (ambient air, 21% oxygen). The results show that during SW stage, with the increase in the oxygen concentration in the intake air, the EAC of the mixture is much closer to the stoichiometric one and more oxygen is made available for oxidation, which results in evidently-improved combustion. The ignition in the first firing cycle starts earlier and peak pressure and maximum heat release rate both notably increase. The maximum engine speed is elevated and HC and CO emissions are reduced considerably. The percent reductions in HC emissions are about 48% and 68% in CO emissions about 52% and 78%; with 23% and 25% OEA, respectively, compared to ambient air. During HI stage, with OEA, the fuel amount per cycle increases due to closed-loop control, the engine speed rises, and speed stability is improved. The HC emissions notably decrease: about 60% and 80% with 23% and 25% OEA, respectively, compared to ambient air. The CO emissions remain at the same low level as with ambient air. During both SW and HI stages, intake air oxygen enrichment causes the delay of spark timing and the increased NOx emissions.

• Journal of Veterinary Clinics
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• v.32 no.5
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• pp.422-425
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• 2015

This study evaluated the myocardial performance on echocardiography after the sedation/anesthesia of medetomidine (D), the combination of medetomidine and tiletamine/zolazepam (DZ), and the combination of medetomidine, tiletamine/zolazepam and tramadol (DZT) in Beagle dogs. Ten healthy adult Beagle dogs (weighing $8.6{\pm}1.0kg$) were enrolled in this study. Heart rate (HR), fractional shortening (%FS), left ventricular ejection fraction (%LVEF), stroke volume (SV), cardiac output (CO), left ventricular internal diameter in systole (LVIDs) and left ventricular internal diameter in diastole (LVIDd) using M-mode echocardiography were measured prior to anesthesia, then every 10 min for 60 min. The HR, %FS, %LVEF, SV and CO were significantly decreased during sedation/anesthesia with D, DZ and DZT combination of anesthesia. Although those anesthetic protocols provided acceptable quality of sedation/anesthesia, levels of cardiovascular suppression were substantial and persistent and thus the continuous monitoring on vital signs should be accompanied in any situation. Close attention is required for dogs with pre-existing heart diseases, when those anesthetic protocols were applied.

• Journal of Korean Medical classics
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• v.29 no.1
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• pp.17-41
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• 2016

Subjects : A literature research on the constitution and medicinal effect & adaptation diseases of "Bullsusan". "Bullsusan" is a herbal prescription composed of Angelicae Gigantis Radix(當歸) and Cnidii Rhizoma(川芎). Objectives : Through the researching on the records of "Bullsusan" in Korean Traditional Medical Books, gain the literature evidence for adaptation to these days child labor as a pre-labor keeping herbal medicine. And have detailed consideration on the constitution of prescription and medicinal effect & adaptation diseases of "Bullsusan". Methods : First, researched the records of "Bullsusan" in Korean Traditional Medical Books which were included at A Series of Korean Medicine(韓國醫學大系) and analysed component ratio, nickname, herbal manufacture and drug processing method, medicinal effect and adaptation diseases. Second, referred related Korean and Chinese researches that examined the medicinal effect and adaptation diseases of "Bullsusan" by scientific experimentation. Conclusions : We found total 46 records of "Bullsusan" from 20 kinds of Korean Traditional Medical Books included at A Series of Korean Medicine. Prescription component ratio of Angelicae Gigantis Radix and Cnidii Rhizoma were 3:2, 1:1, 2:1, 1:1. 3:2 had most 20 records and 1:1 had second 14 records. Especially 1:1 had a tendency of having nickname "Goonguitang", but not must had. First herbal manufacture was powder, it had 8 records. First drug processing method was decocting with water and alcohol, had 19 records. Medical Effects of "Bullsusan" can be induced to next 8, that were "remove get bad blood, give birth new blood", "easy labor by reducing fetal volume", "acceleration of labor", "test of fetal survival, elimination of dead embryo", "elimination of placenta", "revive", "allaying pain", "nourish the blood". From these medical effects, 9 adaptation diseases can be induced. That were "threatened abortion", "womb ache and vaginal bleeding by spontaneous abortion", "pre-labor keeping(prevention of hard labor)", "acceleration of labor", "hard labor", "missed abortion", "postnatal vaginal bleeding, dizziness, asthma, headache, womb ache", "postnatal mastoptosis and mastodynia", "first aid symptom like as dizziness, unconsciousness, stroke caused by excessive bleeding". The medical effect of "acceleration of labor" and "elimination of placenta" have been examined by modern clinical research. The effect of "remove get bad blood, give birth new blood", "allaying pain" and "nourish the blood" have been examined by modern experimental study. But overdosing on "Bullsusan" to pregnant mouse can cause natural abortion, so the proper dose of "Bullsusan" in pregnant period is very important.

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.2
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• pp.87-94
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• 2005

It is not clear whether $Ca^{2+}-induced$ $Ca^{2+}$ release from the sarcoplasmic reticulum (SR) is involved in the regulation of atrial natriuretic peptide (ANP) release. Previously, we have shown that nifedipine increased ANP release, indicating that $Ca^{2+}$ entry via voltage-gated L-type $Ca^{2+}$ channel activation decreases ANP release. The purpose of the present study was two-fold: to define the role of SR $Ca^{2+}$ release in the regulation of ANP release and whether $Ca^{2+}$ entry via L-type $Ca^{2+}$ channel is prerequisite for the SR-related effect on ANP release. Experiments were performed in perfused beating rabbit atria. Ryanodine, an inhibitor of SR $Ca^{2+}$ release, increased atrial myocytic ANP release ($8.69{\pm}3.05$, $19.55{\pm}1.09$, $27.31{\pm}3.51$, and $18.91{\pm}4.76$% for 1, 2, 3, and $6{\mu}M$ ryanodine, respectively; all P<0.01) with concomitant decrease in atrial stroke volume and pulse pressure in a dose-dependent manner. In the presence of thapsigargin, an inhibitor of SR $Ca^{2+}$ pump, ryanodine-induced increase in ANP release was not observed. Thapsigargin attenuated ryanodine-induced decrease in atrial dynamic changes. Blockade of L-type $Ca^{2+}$ channel with nifedipine abolished ryanodine-induced increase in ANP release ($0.69{\pm}5.58$% vs. $27.31{\pm}3.51$%; P＜0.001). In the presence of thapsigargin and ryanodine, nifedipine increased ANP release and decreased atrial dynamics. These data suggest that $Ca^{2+}$-induced $Ca^{2+}$ release from the SR is inversely involved in the regulation of atrial myocytic ANP release.

• Journal of Korean Academy of Nursing
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• v.41 no.2
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• pp.197-203
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• 2011

Purpose: This study was done to identify whether pre-conditioning exercise has neuroprotective effects against cerebral ischemia, through enhance brain microvascular integrity. Methods: Adult male Sprague-Dawley rats were randomly divided into four groups: 1) Normal (n=10); 2) Exercise (n=10); 3) Middle cerebral artery occlusion (MCAo), n=10); 4) Exercise+MCAo (n= 10). Both exercise groups ran on a treadmill at a speed of 15 m/min, 30 min/day for 4 weeks, then, MCAo was performed for 90 min. Brain infarction was measured by Nissl staining. Examination of the remaining neuronal cell after MCAo, and microvascular protein expression on the motor cortex, showed the expression of Neuronal Nuclei (NeuN), Vascular endothelial growth factor (VEGF) & laminin. Results: After 48 hr of MCAo, the infarct volume was significantly reduced in the Ex+MCAo group ($15.6{\pm}2.7%$) compared to the MCAo group ($44.9{\pm}3.8%$) (p<.05), and many neuronal cells were detected in the Ex+ MCAo group ($70.8{\pm}3.9%$) compared to the MCAo group ($43.4{\pm}5.1%$) (p<.05). The immunoreactivity of laminin, as a marker of microvessels and Vascular endothelial growth factor (VEGF) were intensively increased in the Ex+MCAo group compared to the MCAo group. Conclusion: These findings suggest that the neuroprotective effects of exercise pre-conditioning reduce ischemic brain injury through strengthening the microvascular integrity after cerebral ischemia.

• Tribology and Lubricants
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• v.30 no.5
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• pp.278-283
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• 2014

Carbon nanotubes (CNTs) are used in various composite materials to enhance electrical, thermal and mechanical properties of composite materials. In this study, we investigate the wear characteristics of polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) blends containing multi-walled carbon nanotubes (MWCNTs). PC/ABS blends are commonly used in many industrial applications such as cellular phones and display cases and MWCNTs have been added to the PC/ABS blends to improve their electromagnetic interference shielding (EMS). We performed wear tests on PC/ABS blends containing MWCNTs under reciprocating linear sliding conditions with chrome steel balls as a counterpart material. The normal loads were 10, 30, 50, 70, 100 N, the sliding speed was 10 mm/s, the stroke length was 15 mm, and the tests lasted 900 s. The MWCNTs included in the PC/ABS blends lower the wear volume and friction coefficient of the composites. We analyzed the wear debris collected from the composites during the tests in terms of the MWCNT concentration using inductively coupled plasma optical emission spectroscopy. The results show that the quantity of MWCNTs in the debris is proportional to the concentration of MWCNTs in the composite, indicating that the exposure of the MWCNTs to environments by wear could be increased with their concentration in the composite.

• Journal of Life Science
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• v.19 no.11
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• pp.1568-1574
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• 2009

The purpose of this study was to investigate whether group III muscle afferents play an important role eliciting abnormal blood pressure response mediated during passive muscle stretch in prehypertensive individuals. Eleven middle-aged prehypertensive men (average BP 133/80 mmHg) and nine middle-aged normotensive men (average BP 119/74 mmHg) participated in this study. After 1 min rest baseline data collection, the subject's foot was flexed (dorsiflexion) by an automated cybex for one minute. Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial blood pressure (MAP), heart rate, stroke volume, cardiac output, and total peripheral resistance were continuously measured on a beat-by-beat basis from a finger via a Finapres device for 1 minute. To evaluate the role of mechanoreflex, a component of exercise pressor reflex, SBP, DBP, and MAP responses over the course of time were examined. The results showed that the pressor response mediated by the muscle mechanoreflex was faster in prehypertensive individuals compared to the normotensive individuals. The substantial pressor response was observed within mean 20 sec of the onset of passive stretch in prehypertension, while mean 45 sec in normotension (p<0.05). It is concluded that excessive pressor response produced during exercise in prehypertension may be due to the dysfunction of the mechano-receptors.

• Journal of the Korean Society of Fashion and Beauty
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• v.2 no.3 s.3
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• pp.11-18
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• 2004

The purpose of this study was to review the origin and background of well-being, the emerging well-being culture, and the phenomenon and features of the hair beauty affected by it. For this purpose, the researcher reviewed dissertations written between 199a and 2002, copies of the beauty journal Short Hair published between 2002 and 2003, beauty newspapers published between March, 2003 and June, 2004, and relevant Internet sites. When we review the well-being hair style tendency, we may be reminded of a light shaggy cut style with a thick wave volume or a natural wave highlighted, or a natural style with a natural color rendered by the braid technique. The well-being hair styles may be inspired by such natural images as the earth, sand, rock, wind, feather and flowers, while using cut, permanent wave or coloring technique for the hairs, in order to create new hair styles. The goal is to make men in contact with the nature. Meanwhile, as people are more concerned about diverse hair textures, natural and healthy hairs, they want their hairs to look comfortable and active rather than luxurious. The well-being cut styles may be categorized into cut style highlighting healthy hairs with a Bobos luxury and soft and light stroke cut reminiscent of a Bohemian freedom. The well-being permanent style may be divided into thick wave, natural wave, and the permanent style using a strong wave to make hairs look bloated. The hair colors reminding us of some natural images are used to highlight a well-being image. In addition, the concept of well-being pursuing a happy and healthy life has been being introduced into the permanent wave material liquids; such liquids made from natural materials, fruits or herbs increase, while environmental-friendly liquids or materials are used more for healthy hairs. The reason why the well-being culture influences hair styles importantly may be that people's desire of healthy body and mind and a comfortable life is reflected in hair styles. In conclusion, as the hair styles or an index for a new cultural current in our modern age are influenced by the well-being phenomenon, more and more people will put priority on healthy hairs. So, it is deemed necessary to apply the well-being hair styles appropriately to render satisfactory hair styles.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.05
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• pp.84-87
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• 1996

We have been developed electrohydraulic left ventricular assist device and done various in vivo evaluation on the device. Through the in vivo experiment conducted from Jan. 23, 1996 to Feb. 8, we could have experience of long-term evaluation fur the first time. The sheep used in this experiment had survived for 16 days. We used new actuator with reduced size and linear motion guide replacing oil box and ball bearings. Also, we used improved blood chamber with reduced size, reduced weight facilitating fixing the chamber to animal's body, and polymer sac having improved folding pattern. Against suction problem, we used absolute pressure limiter only. Motor current for driving this new actuator was not much higher than older one. Effective stroke volume was about 48 cc. Thrombosis was found around top area and peripheral boundary of the sac and valves. There was no sign of damage from suction problem in the atrium observed at autopsy. Main cause of death was presumed to be progressive formation of thrombosis in the cannulae. In this paper, the results of this experiment are documented.

• Journal of Chest Surgery
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• v.56 no.3
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• pp.155-161
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• 2023

Background: Surgical closure of an atrial septal defect (ASD) is infrequently indicated during infancy. We evaluated the clinical characteristics and outcomes of patients who underwent surgical ASD closure during infancy. Methods: A single-center retrospective review was performed for 39 patients (19 males) who underwent surgical ASD closure during infancy between 1993 and 2020. The median body weight percentile at the time of operation was 9.3. Results: During a median follow-up of 60.9 months, 4 late deaths occurred due to chronic respiratory failure. A preoperative history of bronchopulmonary dysplasia (BPD) was the only risk factor for late mortality identified in Cox regression (hazard ratio, 3.54; 95% confidence interval [CI], 1.75-163.04; p=0.015). The 5-year survival rate was significantly lower in patients with preoperative history of BPD (97.0% vs. 50.0%, p<0.001) and preoperative ventilatory support (97.1% vs. 40.4%, p<0.001). There were significant postoperative increases in left ventricular end-diastolic (p=0.017), end-systolic (p=0.014), and stroke volume (p=0.013) indices. A generalized estimated equation model showed significantly better postoperative improvement in body weight percentiles in patients with lower weight percentiles at the time of operation (<10th percentile, p=0.01) and larger indexed ASD diameter (≥45 mm/m², p=0.025). Conclusion: Patients with ASD necessitating surgical closure during infancy are extremely small preoperatively and remain small even after surgical closure. However, postoperative somatic growth was more prominent in smaller patients with larger defects, which may be attributable to an increase in postoperative cardiac output due to changes in ventricular septal configuration. The benefits of ASD closure in patients with BPD are undetermined.