• Journal of Life Science
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• v.32 no.2
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• pp.175-188
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• 2022

Relaxin has been demonstrated to have regulatory functions on both the smooth muscle and extracellular matrix (ECM) of blood vessels and fibrotic organs. The diverse mechanisms by which relaxin acts on small resistance arteries and fibrotic organs, including the bladder, are reviewed here. Relaxin induces vasodilation by inhibiting the contractility of vascular smooth muscles and by increasing the passive compliance of vessel walls through the reduction of ECM components, such as collagen. The primary cellular mechanism whereby relaxin induces arterial vasodilation is mediated by the endothelium-dependent production of nitric oxide (NO) through the activation of RXFP1/PI3K, Akt phosphorylation, and eNOS. In addition, relaxin triggers different alternative pathways to enhance the vasodilation of renal and mesenteric arteries. In small renal arteries, relaxin stimulates the activation of the endothelial MMPs and EtB receptors and the production of VEGF and PlGF to inhibit myogenic contractility and collagen deposition, thereby bringing about vasodilation. Conversely, in small mesenteric arteries, relaxin augments bradykinin (BK)-evoked relaxation in a time-dependent manner. Whereas the rapid enhancement of the BK-mediated relaxation is dependent on IK_Ca channels and subsequent EDH induction, the sustained relaxation due to BK depends on COX activation and PGI₂. The anti-fibrotic effects of relaxin are mediated by inhibiting the invasion of inflammatory immune cells, the endothelial-to-mesenchymal transition (EndMT), and the differentiation and activation of myofibroblasts. Relaxin also activates the NOS/NO/cGMP/PKG-1 pathways in myofibroblasts to suppress the TGF-β1-induced activation of ERK1/2 and Smad2/3 signaling and deposition of ECM collagen.

• KDI Journal of Economic Policy
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• v.12 no.1
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• pp.93-110
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• 1990

The basic purpose behind the Korean government's policy toward the Korean deep sea fishing industry is to limit growth of the industry. Therefore, the regulations on the industry are generally restrictive and interventionist. The policy is intended to maintain high domestic fish prices in order to protect the domestic coastal fishing industry. Some regulations have also been introduced to maintain "industrial order." Each fishing vessel must obtain a government permit for operation. The permit specifies the kind of fish it can catch, the area of sea in which it can operate, and the port at which it can unload its catches. The number of permits government issues each year is based on the estimates of the demand increase calculated by government officials, and the government traditionally has been fairly conservative in its estimation, reflecting its concern for fish price stabilization, which actually implies a gradual increase of the prices. There is also a restriction on importing vessels from abroad. This regulation is intended to protect the domestic shipbuilding industry. However, this regulation has resulted in an unusually high average age of Korean fishing vessels, causing fishing costs to rise. These regulations and the inflexible response of the regulators to changing circumstances have resulted in many problems: i) high domestic fish prices, which are, to some extent deliberately, inflated to three or four times the level of international prices, resulting in huge consumer welfare losses; ii) over-exploitation of coastal fish resources; iii) provision of a hospitable environment for inefficient firms to survive, which is especially evident from the fact that, despite the high fish prices in Korea, most of the firms in the industry do not enjoy high profitability. It also must be pointed out that the actual beneficiaries of the high fish prices are the large operators, who are protected from competition and provide most of the fish for domestic consumption, rather than the low-income fishing households and small coastal operators whom the policy was originally designed to help. This study proposes a set of regulatory reforms and policy changes which could Promote competition and equity within the industry and allow firms to reduce costs and increase productivity. Such changes can make the industry more efficient and internationally competitive. Major proposals are, among others: minimization of bureaucratic discretion in issuing fishing permits and maintaining transparency in the governments' decision-making processes; reduction of the government permit specifications and simplification of the operational categories within the industry; and removal of the restrictions on importing foreign fishing vessels.

• Journal of Korean Ophthalmic Optics Society
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• v.7 no.1
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• pp.39-43
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• 2002

This study was investigated the anti-angiogenic activities of Cnidium officinale Makino and Tabanus bovinus by using Chorioallantoic membrane (CAM) and rat cornea. First experiment, the fertilized chicken eggs were kept in a humidified egg incubator at $37^{\circ}C$. After 4 days incubation, about 3 ml of albumin was aspirated from eggs with an hypodermic needles through a small hole drilled at the narrow end of the eggs, and the shell membrane on the floor of the air sac was peeled away. Embryos with chorioallantois of 3~5 mm in diameter were employed for the assay of antiangiogenic activity. Retinoic acid was used as a positive control for this experiment. After 48 h of treatment. branching pattern of blood vessels below coverslip containing retinoic acid ($10{\mu}g/egg$) was dramatically decreased. A simiar angiogenic inhibition was observed in the CAM treated with $50{\mu}g/egg$ of Cnidium omcinale Makino and Tabanus bovinus extracts. Second experiment, rat corneal neovascularization was induced by suturing (one stitch) the cornea with 10-0 nylon, and terramycin was applied on the cornea for I week to prevent corneal inflammation. In the cornea of rats untreated with herbal extracts, numerous vessels were usually seen invading the cornea by day 2 or 3 after suture, and reaching the lesion area within 5~6 days. Corneal neovascularization was gradually increased and peaked at 3 weeks. In contrast to this, herbal extracts conspicuously inhibited the angiogenesis, Oral administration of herbal extracts (20 mg/kg body weight/day) for 4 weeks significantly inhibited the rat corneal angiogenesis induced by suture, and the length of blood vessels in herbal medicine-treated rat cornea was conspicuously lower than that in control animals. A similar phenomenon was also observed in the rat cornea treated with thalidomide (200 mg/kg body weight/day). These findings indicate the anti-angiogenic properties of Cnidium officinale Makino and Tabanus bovinus, suggesting that these properties may be one of the pharmacological mechanisms underlying the anti-tumor and anti-metastatic activities of herbal extracts tested in this study.

• Korean Journal of Veterinary Research
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• v.37 no.1
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• pp.71-78
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• 1997

This study was designed to investigate the number of the growing and mature follicles following gonadotrophin treatments for superovulation in mature rats. Eighteen mature rats (Sprague-Duwely, initially 190~230gm) were randomly alloted into 3 groups. One group was control group, another FSH-treated group was injected intramuscularly with 0.5 units of follicular stimulating hormone (FSH) / rat, and third PMS and HCG-treated group was intramuscularly injected with 20~25IU of pregnant mare serum (PMS) / rat and then at the 48 hrs later, with 20~25IU of human chorionic gonadotrophin (HCG) / rat. The uteri and ovaries of rats were collected and then were observed grossly and serial sections of paraffin embedding ovaries were stained with H-E. Number of ovarian follicles by following 3 grades of large, middle and small follicles from secondary and tertiary follicles were investigated by LM photography of preparations. Small follicles were classified as secondary follicles of preantral follicles with more than 2 layers of granulosa cells surrounding the oocyte and middle follicles were classified as secondary follicles with early signs of antral cavity or with more than one small cavity on either side of the oocytes and large follicles were classified as tertiary follicles with a single medium sized antral cavity or large well-formed antral cavity. In gross findings, the uteri were slightly swelling in FSH-treated group and markedly swelling or filled with fluid in the uterine lumen in PMS and HCG-treated group. In histological findings, the shape and size of the follicles were diverse in middle and large follicles of FSH-treated group and PMS and HCG-treated group, and proportion of atretic follicles was increased in FSH-treated group and PMS and HCG-treated group than those in control group. The uteri of FSH-treated group and PMS and HCG-treated group were hypertropied or filled with fluid in the lumens and walls of uteri. The wall tissue layers were flattened and their blood and lymph vessels were dilated. The mean number of follicle per ovary in control group were appeared to be $17.1{\pm}5.6$($14.0%{\pm}4.6%$), $37.8{\pm}9.1$($30.9{\pm}7.4%$) and $67.6{\pm}30.1$($55.2{\pm}24.6%$) respectively at large, middle and small follicles and total number of these 3 grade follicles were appeared to be $122.5{\pm}40.0$. The mean number of follicle per ovary in FSH-treated group were appeared to be $22.8{\pm}7.0$($17.4%{\pm}5.3%$), $43.4{\pm}6.6$($33.2{\pm}5.1%$) and $64.5{\pm}13.0$($49.3{\pm}9.9%$) respectively at large, middle and small follicles and total number of these 3 grade follicles were appeared to be $130.7{\pm}16.6$. The mean number of follicle per ovary in PMS and HCG-treated group were appeared to be $29.7{\pm}11.0$($16.3%{\pm}6.0%$), $61.9{\pm}17.2$($33.9{\pm}9.4%$) and $91.1{\pm}28.2$($49.9{\pm}15.4%$) respectively at large, middle and small follicles and total number of these 3 grade follicles were appeared to be $182.6{\pm}32.7$. The above findings reveal that large follicles were increased 29.8% in FSH-treated group and 73.7% in PMS and HCG-treated group than those in control group and in histologic findings, proportion of atretic follicles were more increased in ovaries with more number of more developing follicles.

• Journal of Fisheries and Marine Sciences Education
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• v.21 no.1
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• pp.52-58
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• 2009

With the increase of marine traffic capacity, marine accidents have also been increased for recent several years. Especially watch officer must maneuver not entering into the safety minimum approaching distances when two power-driven vessels are crossing. The author calculated the safety minimum approaching distances to provide a navigator with them based on zig-zag motion by experimental ship. The obtained results are summarized as follows : 1. The greatest distance is to be kept by the give way vessel to avoid collision when the crossing course angle is $90^{\circ}$. In this case the safety minimum approaching distance must be more than from 5 times to 11 times of her own length according to her size. 2. The watch officer of the give way vessel must always take an action to avoid collisions outside of the safety minimum approaching distance. 3. When the navigator used rudder to small angle than to large angle to avoid other vessel he must take action outside the sufficient safety minimum outside distances in advance. 4. Risk of collision in crossing situation is more greater in obtuse situation than in acute one.

• Journal of Yeungnam Medical Science
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• v.20 no.1
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• pp.71-78
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• 2003

Unilateral absence of a pulmonary artery (UAPA) is a rare congenital anomaly that is frequently associated with other cardiovascular anomalies first reported by Fraentzel in 1968. Most patients who have no associated cardiac anomalies have only minor or absent symptoms. We experienced a case of isolated UAPA in a young female presenting hemoptysis. The chest radiograph showed a small left lung volume and high resolutional CT of chest showed multiple subpleural nodules and centrilobular nodules in parenchyma. The video-assisted thoracoscopic biopsy revealed diffuse dilated vessels in visceral pleura. The pulmonary angiogram confirmed the absence of the left main pulmonary artery.

• Journal of Yeungnam Medical Science
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• v.27 no.2
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• pp.159-164
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• 2010

Hematoma of gastric wall is very rare, and occasionally associated with coagulopathy, trauma, peptic ulcer disease, and therapeutic endoscopy. Ischemic gastric necrosis is also rare because of the abundant anastomotic supply to the stomach, and it is usually associated with surgery and disruption of the major vessels. Endoscopic submucosal injection of hypertonic saline-epinephrine (HS-E) is a safe, cost-effective, and widely used therapy for hemostasis but it may cause tissue necrosis and perforation. We describe a case of gastric wall hematoma with oozing bleeding after endoscopic gastric mucosa biopsy in 71-year old woman with chronic renal failure and angina pectoris undergoing anti-platelet medication. We injected a small dose of HS-E (7ml) for controlling oozing bleeding. Two days later, endoscopy showed huge ulcer with necrotic tissue at the site of previously hematoma. Therefore we should pay particular attention for hematoma and mucosal necrosis when performing endoscopic procedure in a patients with high bleeding and atherosclerotic risk.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.2
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• pp.164-170
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• 2013

With the introduction of increasingly large-sized ships, the conditions of main domestic port facilities remain the same as in the past. So, there is high probability that marine traffic congestion can occur at the certain ship's routes. The standard ship's length used to assess the marine traffic congestion of domestic trade port is 70 meters. It has been in use for the last 30 years, so, its usefulness is highly recommended for review. This study deeply analyzes the tendency of ship's dimensional changes according to recent enlargement of ship's size by utilizing the particulars of 60,000 ships saved in domestic Port-MIS database and suggests the standard ship's length by figuring out the correlation between length of ship and gross tonnage. In addition, the basis of statistical data on the ship's tonnage in domestic trade over the last five years suggests the standard ship's length by deriving the reference point of cumulative incidences that occupy more than over 50 %, except for small vessels. It is necessary to consider the characteristic of each domestic trade port before the actual application of suggested standard ship's length.

• Journal of the Korean Society for Nondestructive Testing
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• v.9 no.1
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• pp.30-38
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• 1989

Since the nuclear power plants in Korea have been operated in 1979, the nondestructive testing (NDT) of pressure vessels and/or piping welds plays an important role for maintaining the safety and integrity of the plants. Ultrasonic method is superior to the other NDT method in the viewpoint of the detectability of small flaw and accuracy to determine the locations, sizes, orientations, and shapes. As the service time of the nuclear power plants is increased, the radiation level from the components is getting higher. In order to get more quantitative and reliable results and secure the inspector from the exposure to high radiation level, automation of the ultrasonic equipments has been one of the important research and development(R & D) subject. In this research, it was attempted to visualize the shape of flaws presented inside the specimen using a Modified C-Scan technique. In order to develope Modified C-Scan technique, an automatic ultrasonic scanner and a module to control the scanner were designed and fabricated. IBM-PC/XT was interfaced to the module to control the scanner. Analog signals from the SONIC MARK II were digitized by Analog-Digital Converter(ADC 0800) for Modified C-Scan display. A computer program has been developed and has capability of automatic data acquisition and processing from the digital data, which consist of maximum amplitudes in each gate range and locations. The data from Modified C-Scan results was compared with shape from artificial defects using the developed system. Focal length of focused transducer was measured. The automatic ultrasonic equipment developed through this study is essential for more accurate, reliable, and repeatable ultrasonic experiments. If the scanner are modified to meet to appropriate purposes, it can be applied to automation of ultrasonic examination of nuclear power plants and helpful to the research on ultrasonic characterization of the materials.

• Journal of Welding and Joining
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• v.32 no.6
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• pp.8-13
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• 2014

One of the main challenges of the automatic arc welding process which has been widely used in various constructions such as steel structures, bridges, autos, motorcycles, construction machinery, ships, offshore structures, pressure vessels, and pipelines is to create specific welding knowledge and techniques with high quality and productivity of the production-based industry. Commercially available automated arc welding systems use simple control techniques that focus on linear system models with a small subset of the larger set of welding parameters, thereby limiting the number of applications that can be automated. However, the correlations of welding parameters and bead geometry as welding quality have mostly been linked by a trial and error method to adjust the welding parameters. In addition, the systematic correlation between these parameters have not been identified yet. To solve such problems, a new or modified models to determine the welding parameters for tandem GMA (Gas Metal Arc) welding process is required. In this study, A new predictive model called STACO model, has been proposed. Based on the experimental results, STACO model was developed with the help of a standard statistical package program, MINITAB software and MATLAB software. Cross-comparative analysis has been applied to verify the reliability of the developed model.