• Journal of Microbiology and Biotechnology
• /
• v.26 no.1
• /
• pp.130-138
• /
• 2016

The use of antibiotics in aquaculture raises environmental and food safety concerns because chronic exposure of an aquatic ecosystem to antibiotics can result in the spread of antibiotic resistance, bioaccumulation of antibiotics in the organisms, and transfer of antibiotics to humans. In an attempt to overcome these problems, high-concentration red clay was applied as an alternative antibiotic against the following common fish pathogens: Aeromonas salmonicida, Vibrio alginolyticus, and Streptococcus equinus. The growth of A. salmonicida and V. alginolyticus was retarded by red clay, whereas that of S. equinus was promoted. Phase contrast and scanning electron microscopy analyses confirmed the attachment of red clay on cell surfaces, resulting in rapid gravitational removal and cell surface damage in both A. salmonicida and V. alginolyticus, but not in S. equinus. Different cell wall properties of grampositive species may explain the unharmed cell surface of S. equinus. Significant levels of oxidative stress were generated in only the former two species, whereas significant changes in membrane permeability were found only in S. equinus, probably because of its physiological adaptation. The bacterial communities in water samples from Oncorhynchus mykiss aquacultures supplemented with red clay showed similar structure and diversity as those from oxytetracycline-treated water. Taken together, the antibiotic effects of high concentrations of red clay in aquaculture can be attributed to gravitational removal, cell surface damage, and oxidative stress production, and suggest that red clay may be used as an alternative for antibiotics in aquaculture.

• Journal of Digital Convergence
• /
• v.12 no.8
• /
• pp.229-234
• /
• 2014

Vehicular electronic communication system has continued to develop in favor of high performance and user convenience with the evolution of auto industry. Yet, due to the nature of communication system, concerns over intruder attacks in transmission sections have been raised with a need for safe and secure communication being valued. Any successful intruder attacks on vehicular operation and control systems as well as on visual equipment could result in serious safety and privacy problems. Thus, research has focused on hardware-based security and secure communication protocols. This paper proposed a safe and secure vehicular communication protocol, used the formal verification tool, Casper/FDR to test the security of the proposed protocol against different types of intruder attacks, and verified that the proposed protocol was secure and ended without problems.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.24 no.1
• /
• pp.97-106
• /
• 2014

CCTV(Closed Circuit television) is one of the widely used physical security technologies and video acquisition device installed at specific point with various purposes. Recently, as the CCTV capabilities improve, facial recognition from the information collected from CCTV video is under development. However, in case these technologies are exploited, concerns on major privacy infringement are high. Especially, a computer connected to a particular space images taken by the camera in real time over the Internet has emerged to show information services. In the privacy law, safety measures which is related with biometric template are notified. Accordingly, in this paper, for the protection of privacy video information in the video surveillance system, the technical and managerial requirements for video information security are suggested.

• Journal of Gastric Cancer
• /
• v.14 no.2
• /
• pp.105-110
• /
• 2014

Purpose: The advantages of totally laparoscopic surgery in early gastric cancer (EGC) are unproven, and some concerns remain regarding the oncologic safety and technical difficulty. This study aimed to evaluate the technical feasibility and clinical benefits of totally laparoscopic distal gastrectomy (TLDG) for the treatment of gastric cancer compared with laparoscopy-assisted distal gastrectomy (LADG). Materials and Methods: A retrospective review of 211 patients who underwent either TLDG (n=134; 63.5%) or LADG (n=77; 36.5%) for EGC between April 2005 and October 2013 was performed. Clinicopathologic features and surgical outcomes were analyzed and compared between the groups. Results: The operative time in the TLDG group was significantly shorter than that in the LADG group (193 [range, 160~230] vs. 215 minutes [range, 170~255]) (P=0.021). The amount of blood loss during TLDG was estimated at 200 ml (range, 100~350 ml), which was significantly less than that during LADG, which was estimated at 400 ml (range, 400~700 ml) (P<0.001). The hospital stay in the TLDG group was shorter than that in the LADG group (7 vs. 8 days, P<0.001). One patient from each group underwent laparotomic conversion. Two patients in the TLDG group required reoperation: one for hemostasis after intraabdominal bleeding and 1 for repair of wound dehiscence at the umbilical port site. Conclusions: TLDG for distal EGC is a technically feasible and safe procedure when performed by a surgeon with sufficient experience in laparoscopic gastrectomy and might provide the benefits of reduced operating time and intraoperative blood lossand shorter convalescence compared with LADG.

• Journal of Environmental Health Sciences
• /
• v.38 no.2
• /
• pp.166-174
• /
• 2012

Introduction: After 17 years since the first production of humidifier disinfectants in Korea, Korea Centers for Disease Control and Prevention (KCDC) announced that the odds ratio of lung injury related with humidifier disinfectant usage was 47.3 (95% confidence interval 6.0-369.7) according to a case-control study with 18 adult cases, including 8 pregnant women at a university hospital in Seoul. Results: From September 2011 to April 2012, one-hundred and seventy four victim cases have been reported to an environmental non-governmental group (NGO). We summarized timetable of humidifier disinfectants accidents, analyzed health outcomes (death, lung or lung and heart transplantation, pulmonary disease) of reported victims, and classified some information for humidifier disinfectants with health outcomes, and government action for this accident. Among the victims, number of death cases are 52 (30.0%), including 26 babies less than 3 years old. Sixty-nine victims come from twenty-seven family with 2 to 4 members per family. About twenty types of humidifier disinfectant products and about 600,000 product items a year have been sold. Fifty-two death cases used 7 different types of disinfectant products, including imported goods and some private brands of well-known supermarkets. KCDC confirmed inhalation toxicity of 6 products through an animal experimental test, and based on this observation recalled disinfectants containing PHMG (polyhexamethylene guanidine) and PGH (Oligo(2-(2-ethoxy)ethoxyethyl guanidinium chloride). Discussions: The use of these biocides involved highly fatal consequences among biologically vulnerable victims, such as pregnant women, several family member victims after semi-acute exposure. This is the first biocide disaster in Korea with non-specific targets, and unknown scale of victims, warranting concerns on use of biocides in the living environment. Conclusions: Special administrative agency for chemical safety and compensation act for environmental health victims are needed to prevent similar problems.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.16 no.5
• /
• pp.81-88
• /
• 2012

Turbopump is a key component in liquid rocket engines, and reducing weight while maintaining structural safety is one of the major concerns of turbopump designers. To reduce the weight aluminium alloy castings instead of steel casings are introduced. The casting process is especially useful for enhancement of productivity and for reduction of product costs. But, since castings are used in space vehicle engines, reliability cannot be compromised. Therefore, proper design, production process and thorough investigation should be performed to ensure structural integrity. In this study inlet casings for a fuel pump were casted with A356.0-T6 alloy and using one of them a burst test was conducted to ensure structural integrity. Structural analysis is performed for simulation, and with multiple strain gages strains are measured and compared with predictions.

• Journal of the Korean Society for Railway
• /
• v.15 no.6
• /
• pp.604-608
• /
• 2012

Traditionally, the track circuits have been used for the purpose of train locating. However, the recent train control systems like a CBTC(Communications Based Train Control) do not utilize the track circuits to minimize the amount of ground signal devices. Therefore, there are increasing concerns over the system that can locate the position of train exactly without using the track circuits. Then, the contactless locating methods are added to ensure safety when the shunting sensitivity of the track circuit becomes low for the existing sections equipped with the track circuits. In this paper, a prototype of train locating device has been designed and tested, which utilizes the current phase difference upon magnetic field variation. The results show improved features of this method over the conventional track circuits method.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.13 no.5
• /
• pp.41-50
• /
• 2009

Following an earthquake, the major concerns for damaged buildings are their safety/risk in the event of aftershocks, and thus a quantitative damage assessment must be performed in order to evaluate their residual seismic capacity and to identify necessary actions for the damaged buildings. Post-event damage evaluation is therefore as essential for the quick recovery of a damaged community as pre-event seismic evaluation and strengthening of vulnerable buildings. The objective of this study is to develop a post-earthquake seismic evaluation method for RC frames with URM infill wall for typical school buildings. For this purpose, full-scale, one-bay, single-story specimens having different axial loads in columns are tested under cyclic loadings. During the tests, residual crack widths, which can also be found in damaged buildings, are measured in order to estimate the residual seismic capacity from the observed damage. In this paper, the relationship between the measured residual crack width and the residual seismic capacity is discussed analytically and experimentally, and reduction factors are proposed to estimate the residual seismic capacity based on the observed damage level.

• Clinical and Experimental Reproductive Medicine
• /
• v.43 no.1
• /
• pp.26-30
• /
• 2016

Objective: We aimed to investigate the prevalence of erectile dysfunction (ED) and the usage of phosphodiesterase type 5 (PDE5) inhibitors for ED treatment in infertile couples. Methods: A total of 260 male partners in couples reporting infertility lasting at least 1 year were included in this study. In addition to an evaluation of infertility, all participants completed the International Index of Erectile Function (IIEF)-5 questionnaire to evaluate their sexual function. The participants were asked about their use of PDE5 inhibitors while trying to conceive during their partner's ovulatory period and about their concerns regarding the risks of PDE5 inhibitor use to any eventual pregnancy and/or the fetus. Results: Based on the IIEF-5 questionnaire, 41.5% of the participants (108/260) were classified as having mild ED (an IIEF-5 score of 17-21), while 10.4% of the participants (27/260) had greater than mild ED (an IIEF-5 score of 16 or less). The majority (74.2%, 193/260) of male partners of infertile couples had a negative perception of the safety of using a PDE5 inhibitor while trying to conceive. Only 11.1% of men (15/135) with ED in infertile couples had used a PDE5 inhibitor when attempting conception. Conclusion: ED was found to be common in the male partners of infertile couples, but the use of PDE5 inhibitors among these men was found to be very low. The majority of male partners were concerned about the risks of using PDE5 inhibitors when attempting to conceive. Appropriate counseling about this topic and treatment when necessary would likely be beneficial to infertile couples in which the male partner has ED.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.31 no.2
• /
• pp.104-112
• /
• 2018

Objectives : The purpose of this study is to examine whether the topical preparations containing 12 herbal extracts is effective for patients with atopic dermatitis. Methods : We retrospectively reviewed the medical records of 11 patients who were prescribed topical preparations containing 12 herbal extracts on the outpatient clinic of 4 hospitals; Noble Korean Medicine Clinic, Amar Korean Medicine Clinic, Chung-Yeon Korean Medical Hospital, Donggwangju Chung-Yeon Korean Medical Hospital. Results and Conclusions : A total of 11 patients were included in the selection and exclusion criteria. The OSI mean value before treatment and at the last treatment day decreased significantly from $37.03{\pm}16.75$ to $13.32{\pm}9.83$, and the mean value of EASI decreased from $13.33{\pm}12.85$ to $2.78{\pm}5.00$, which was statistically significant. No safety concerns were reported. The results of this study confirmed the possibility that the topical preparations can be effective in moderate to severe infants, adolescents, and adult atopic dermatitis patients.