Donga College of Health

Thermal energy storage (TES) is a key technology in the pursuit of cleaner energy production that enables the more efficient use of renewable energy sources and reduces reliance on fossil fuels. Phase change material emulsions (PCMEs) are studied as TES and transportation mediums. A stable PCME with n-hexadecane (HXD) as a dispersed phase and deionized water as base fluid was successfully fabricated using sodium dodecyl sulfate as a surfactant. Functionalized multi-walled carbon nanotubes (F-MWCNT) were incorporated into the emulsion as an additive to reduce supercooling and enhance thermal conductivity (TC). The prepared emulsions were analyzed in terms of droplet size distribution, phase change properties, stability, TC, and viscosity. The surfactant significantly improved the PCME stability and prevented phase separation. The average droplet size and zeta potential for PCME without nano additive were 166.9–202.2 nm and −67.56 mV, respectively, whereas for PCME with F-MWCNT, 183.41–188.73 nm and −49.53 mV, respectively. The latent heat increased as the concentration of the dispersed phase PCM was higher. The underlying mechanism for the TC enhancement of 22.9 % with the addition of F-MWCNT was investigated. The findings suggest that the developed PCME with F-MWCNT is a promising candidate for TES applications, offering efficient energy management and enhanced thermal performance.

Black soldier fly farming has increased in recent years. The black soldier fly larvae convert low-grade organic materials into high-value food, feed and technical products. To meet the rising demands for proteins in the feed and food industries, there is a need to improve the efficiency of production. Selective breeding can play an important role in such a scenario. Here we present the outcomes of a breeding program for increased larval weight, that started in 2019. The performance of the selected line over the base population line was evaluated in six rounds, under different environmental conditions. Under industrial conditions, an average improvement of +39% in larval weight, +34% in wet crate yield, +26% in dry matter crate yield, +32% in crude protein crate yield and +21% crude fat crate yield was achieved. This research clearly demonstrates the potential of selective breeding for improved efficiency when farming black soldier fly.

It is known that approximately 10% of successful quitters relapse annually. This study aimed to investigate the factors related to long-term smoking relapse in individuals who succeeded in maintaining smoking cessation for 6 months after attending a regional smoking cessation program.This study enrolled 943 individuals registered for the regional smoking cessation program at the Busan Smoking Cessation Center in 2018–2019 who maintained smoking cessation for 6 months. A survey was conducted using a smartphone link or through phone calls, and the data for 305 participants who finally completed the survey were analyzed. The questionnaire addressed individual, inter-individual, organizational, and community-level factors related to smoking relapse. Multivariate logistic regression analysis was performed to evaluate the factors associated with smoking relapse by period. The Cox proportional hazard regression model was used for the factors associated with smoking relapse for the entire period.The smoking relapse rate at the time of the survey was 25.4%. In the analysis of smoking relapse by period, relapse was associated with the belief that smoking relieves stress, the number of single-person households, and poor subjective health status. In the analysis of smoking relapse during the entire period, we observed a significant association with the belief that smoking relieves stress (hazard ratio [HR]: 2.65, 95% confidence interval [CI]: 1.52–4.61), single-person households (HR: 1.95, 95% CI: 1.16–3.26), and high levels of emotional stress (HR: 1.72, 95% CI: 1.04–2.85).Long-term follow-up is necessary to prevent smoking relapse in single-person households, individuals who believe that smoking relieves stress, and those experiencing high levels of subjective emotional stress. Interventional therapies for stress relief and awareness improvement in smokers need to be developed.

Abstract Background This study explores the pathways of nurses in LTCHs and its underlying conditions in Korea. Nursing shortage in long-term care setting has been a worldwide concern. Although the factors of staying or leaving of nurses in long term care hospitals (LTCHs) have been reported, few studies have examined the trajectory and conditions of nurses staying in and leaving LTCHs. Methods A qualitative study design with a grounded theory approach was conducted. Data were collected in one to one interviews. Purposive and theoretical sampling led to the inclusion of 17 registered nurses with diverse characteristics from 14 LTCHs in a metropolitan city in South Korea. Individual, in-depth interviews were conducted. Data collection and analysis coincided. Data were analyzed using open and focused coding, constant comparison, theoretical sampling and memoing, and this enabled the construction of a substantive theory. Results Seeking work-life balance was the core category of nurses’ pathway. Consequences of nurses’ pathway were categorized into three groups: thriving, surviving, and leaving. Thriving nurses in LTCHs found meaning in their work, fostered good relationships, and saw opportunities for growth. Surviving nurses in LTCHs were enduring their jobs in LTCHs, having a work-life balance, and supportive nursing leader. Leaving group nurses wished to leave LTCHs due to lack of professional growth, unappealing work, continuing conflict, and social stigma. However, compensation, work system, and interpersonal relationships were the common moving conditions for all three groups. Conclusions This study provided the trajectory and conditions of nurses to enter, stay, move, or leave at LTCHs. Understanding the pathways for staying or leaving can be used as a strategy for successful retention of registered nurses in LTCHs.

Cordyceps militaris has been used in traditional Chinese medicine owing to its anticancer and immunomodulatory activities. Germanium compounds have also been shown to be associated with many pharmacological functions, such as antimicrobial, antiviral, antitumor, antimutagenic, and immunomodulating effects. In this study, we examined the biological properties of hot water extract from mycelial liquid culture of germanium-enriched C. militaris (CMGe). CMGe displayed a concentration-dependent antiproliferation activity against four human cancer cell lines. The antiproliferative activity of CMGe was 2−4-fold lower than that of hot water extract from mycelial liquid culture in C. militaris (CM). However, CM had a concentration-dependent cytotoxicity to human bone marrow-derived mesenchymal stem cells (MSCs). Contrastingly, CMGe did not cause any cellular damage to MSCs. MSCs cultured with CMGe displayed an increased proliferative activity with no cytotoxic effect. The oral administration of CMGe inhibited increased tumor volume and weight compared with the control group. CMGe has the potential to be used as an industrial product in medicinal foods as well as in pharmaceutical products.

Jeong Su Choi, Sang Yong Park, Man Gil Yang, Dong Beom Lee, Tae Bok Lee, Ji Hye Heo, Min Woo Lee, and Suhng Wook Kim. Korean J Clin Lab Sci. 2016;48:169-75. https://doi.org/10.15324/kjcls.2016.48.3.169

It was carried out a review of operating limit analysis for small high-speed boat by author. In general, a review of ship's seakeeping performance is performed in the step of ship design, but this study was carried out in the state of completion of boat. Motion performance of Pitch, Vertical and Lateral acceleration and Slamming were satisfied in some encounter angle but deck wetness was not satisfied in all it does the analysis. As a result, sea state rather than the speed and encounter angle of vessel have a greater effect on the seakeeping performance of target vessel. It seems to be due to the size of the target ship.

생배추의 저온저장에 적합한 용기 및 기간을 살펴보고자, polypropylene 재질의 상자, polypropylene 재질의 그물망, high density polyethylene 재질의 컨테이너에 생배추를 담아 2달간 보관하였다. High density polyethylene 재질의 컨테이너에 담아 보관한 생배추의 폐기율이 가장 낮아 이것이 가장 효율적인 보관 용기인 것으로 보이며, 저장기간은 배추의 폐기율 및 보관비용 등을 고려했을 때 1달 이상이 되는 것은 바람직하지 않을 것으로 보인다. 저장기간이 다른 생배추로 절임배추를 제조하여 그 품질 특성을 살펴본 결과, 생배추로의 저장기간 없이 바로 절여서 만든 절임배추는 8주차 때 pH 4.0～4.3, 총균 및 유산균 10? cfu/g 이상, 탄력성 50% 이하를 나타내고, 8주차가 지나면서 변질이 상당히 진행되어 이의 저장 한계는 약 8주 이내인 것으로 사료된다. 1달, 2달간 저장한 생배추로 제조한 절임배추는 pH, 염도, 미생물, 탄력성 모두 생배추로의 저장기간 없이 바로 절여서 만든 절임배추의 경우와 비슷한 양상으로 변화하나 저장기간이 길어질수록 품질 저하가 보다 빠른 것으로 나타나, 저장 한계는 각각 약 6주와 4주 이내인 것으로 생각된다. 따라서 절임배추의 품질 측면을 고려하였을 때도 저장기간이 긴 생배추를 사용하는 것은 바람직하지 않으며, 생배추로서의 저장기간은 약 1달, 이를 이용한 절임배추로의 저장기간은 약 6주 정도가 가능한 것으로 보인다.

In order to develop a method for the removal of hydrogen sulfide via a biological process, two different packing materials were tested to assess their capabilities as biofilter bed materials under variable conditions of two parameters: inlet gas concentration and inlet gas flow rate. We detected a maximal elimination capacity (critical loading rate) of 515.1 (410.5) g-H2S/m3·hr, and 415.5 (80.0) g-H2S/m3·hr, respectively, when polypropylene fibrils and volcanic stone were employed as supporting materials. The results of this study show that the application of polypropylene fibrils might be a favorable choice as a packing material in biofilter for the biological removal of hydrogen sulfide.