Maritime Security in East Asia: Major Issues and Regional Responses

The current maritime security environment of East Asia is a complicated mix of old and new challenges. The major issues include island and boundary disputes, naval arms build-up, protection of sea-lanes, navigational regimes and activities in the exclusive economic zone, competition over resources, and maintenance of law and order at sea. These issues, unless dealt with adequately, could pose serious threats to regional stability. The most urgent task for the region in responding to these challenges is the building of a stable and secure maritime regime as well as the implementation of maritime confidence-building measures

A NUMERICAL STUDY ON THE OPEN WATER PERFORMANCE OF A PROPELLER WITH SINUSOIDAL PITCH MOTION

When a ship operates in waves, the ship moves with 6 degrees-of-freedom, and a propeller at the stern of the ship cannot avoid moving due to the ship motion. Therefore, it is important to analyse the propulsion performance while considering the ship motion in waves for efficient ship operation. The pitch motion of the ship has a dominant effect on the variation of the propeller performance and results in sinusoidal pitch motion of the propeller. In this study, a numerical analysis was done using a KP458 model propeller with a diameter of 10 cm, which was designed for the KLVCC2 body plan. The propeller performance was calculated using computational fluid dynamics (CFD) at several constant tilt angles. Numerical simulations were then conducted with sinusoidal pitch motion in several conditions of varying pitch angle. The variations of the thrust and torque of the propeller in sinusoidal pitch motion were compared with the results obtained in constant tilt angles

Scale-up study for ex-vivo expansion of allogeneic natural killer cells in stirred-tank bioreactor

Natural killer (NK) cells are a type of lymphocyte in the blood that are responsible for innate and adaptive immune response, and they mature in the liver and bone marrow. Being a key role in host defense system with direct and indirect killing of virus-infected cells or cancer cells, NK cell has been considered an attractive candidate for cancer therapy. Peripheral blood shows the low frequency of NK cells, so ex vivo expansion method is important to obtain sufficient NK cells for therapeutic use. Currently, we successfully developed bioreactor process for NK cell expansion on lab-scale. Stirred-tank bioreactor could be considered as optimal alternative system for large-scale NK cell expansion compared with other ones because it is automated, less labor intensive, scalable, well-controlled and cost-effective. In bioreactor process, agitation is one of important parameters for NK cell expansion because it is necessary to provide homogenous culture conditions. So we defined effects of agitation in bioreactor and figured out an optimum condition. After that scale-up studies were carried out with manufacturing-scale bioreactor based on these results. The results in terms of growth rate, viability cytotoxicity and purity, were comparable with lab-scale

Risk Factors for Recurrence of Symptomatic Common Bile Duct Stones after Cholecystectomy

Purpose. The recurrence of CBD stone is still observed in a considerable number of patients. The study was to evaluate the risk factors for recurrence of symptomatic CBD stone in patients who underwent cholecystectomy after the removal of CBD stone. Methods. The medical records of patients who underwent removal of CBD stone with subsequent cholecystectomy were reviewed. The risk factors for the recurrence of symptomatic CBD stone were compared between the recurrence and the nonrecurrence group. Results. The mean follow-up period was 40.6 months. The recurrence of symptomatic CBD stones was defined as the detection of bile duct stones no sooner than 6 months after complete clearance of CBD stones, based on symptoms or signs of biliary complication. 144 patients (68 males, 47.2%) were finally enrolled and their mean age was 59.8 (range: 26~86) years. The recurrence of CBD stone occurred in 15 patients (10.4%). The mean period until first recurrence was 25.9 months. The presence of type 1 or 2 periampullary diverticulum and multiple CBD stones were the independent risk factors. Conclusion. For the patients with type 1 or 2 periampullary diverticulum or multiple CBD stones, careful followup is needed for the risk in recurrence of symptomatic CBD stone

Orbital Apex Syndrome in a Patient with Sphenoid Fungal Balls

Orbital apex syndrome (OAS) is a rare disease that presents with a complex of symptoms, including ophthalmoplegia, ptosis and visual loss. Due to the poor prognosis, making a prompt diagnosis and administering the appropriate treatment must be initiated without delay if OAS is suspected. We report here on a case of a patient with sphenoid fungal balls, and he presented with acute visual loss and ophthalmoplegia

Tinea incognito simulating herpes simplex virus infection

A 30-year-old-man presented with a 2-month history of a facial lesion. He was examined by general practitioners, and the eruption was diagnosed as eczema. Topical corticosteroid was applied for 1 month, and the eruption initially seemed to improve with this treatment; but later on, it persisted, and gradually extended in size. Dermatological examination revealed the presence of grouped erythematous papules, vesicles and crusts on erythematous bases, on the right lower eyelid (Fig. 1A). He had no medical history, and no family member who had had similar skin eruptions or symptoms. The initial clinical differential diagnosis included herpes simplex, herpes zoster, and allergic contact dermatitis, caused by an antibiotic eye drop.OAIID:oai:osos.snu.ac.kr:snu2014-01/102/2008000790/3SEQ:3PERF_CD:SNU2014-01EVAL_ITEM_CD:102USER_ID:2008000790ADJUST_YN:NEMP_ID:A079501DEPT_CD:801CITE_RATE:.611FILENAME:tinea incognito simulating hsv.pdfDEPT_NM:의학과SCOPUS_YN:YCONFIRM:

Obstructive ileus caused by phlebosclerotic colitis

A 57-year-old man with chronic kidney disease and a history of using numerous herbal medications visited Inje University Ilsan Paik Hospital for abdominal pain and vomiting. An abdominal radiograph showed diffuse small bowel distension containing multiple air-fluid levels and extensive calcifications along the colon. Computed tomography showed colon wall thickening with diffuse calcification along the colonic mesenteric vein and colonic wall. Colonoscopy, performed without bowel preparation, showed bluish edematous mucosa from the transverse to the distal sigmoid colon, with multiple scar changes. At the mid transverse colon, a stricture was noted and the scope could not pass through. A biopsy of the stricture site revealed nonspecific changes. The patient was diagnosed with phlebosclerotic colitis. After the colonoscopy, the obstructive ileus spontaneously resolved, and the patient was discharged without an operation. Currently, after 2 months of follow-up, the patient has remained asymptomatic. Herein, we report the rare case of an obstructive ileus caused by phlebosclerotic colitis with a colon stricture

Association between glycemic status and the risk of acute pancreatitis: a nationwide population-based study

Background Although diabetes is reportedly associated with the occurrence of acute pancreatitis (AP), the risk of AP according to the duration and severity of diabetes is not yet clear. We aimed to investigate the risk of AP based on glycemic status and the presence of comorbidities using a nationwide population-based study. Methods We enrolled 3,912,496 adults who underwent health examinations under the National Health Insurance Service in 2009. All participants were categorized by glycemic status as normoglycemic, impaired fasting glucose (IFG), or diabetes. Baseline characteristics and the presence of comorbidities at the time of health check-up were investigated, and the occurrence of AP was followed up until 31 December 2018. We estimated the adjusted hazard ratios (aHRs) for AP occurrence according to the glycemic status, duration of diabetes (new-onset, duration < 5 years, or ≥ 5 years), type and number of anti-diabetic medications, and presence of comorbidities. Results During the observation period of 32,116,716.93 person-years, 8,933 cases of AP occurred. Compared with normoglycemia, the aHRs (95% confidence interval) were 1.153 (1.097–1.212) in IFG, 1.389 (1.260–1.531) in new-onset diabetes, 1.634 (1.496–1.785) in known diabetes < 5 years, and 1.656 (1.513–1.813) in patients with known diabetes aged ≥ 5 years. The presence of comorbidities associated with diabetes severity had a synergistic effect on the relationship between diabetes and AP occurrence. Conclusion As glycemic status worsens, the risk of AP increases, and there is a synergistic effect when comorbidities coexist. To reduce the risk of AP, active control of factors that can cause AP should be considered in patients with long-standing diabetes and comorbidities