• Structural Engineering and Mechanics
• /
• 제84권2호
• /
• pp.167-180
• /
• 2022

A strategic structure when exposed to direct hit of conventional bomb/projectile are severely damaged because of large amounts of energy released by the impact and penetration of bomb. When massive concrete slabs suffer a direct hit, the energy released during impact and penetration process are able to easily break up large mass of concrete. When over stressed under such impact of bombs, the concrete structure fails showing brittle behavioural nature. This paper is intended to study and suggest the protective measures for structures used for strategic application by adopting a means to dissipate the large quantum of energy released. To quantitatively evaluate the force, displacement and energy in such scenario, a fine numerical model of the proposed layered structure of different combinations was built in ANSYS programme in which tri-nitrotoluene (TNT) explosive was detonated at penetration depth calculated for GP1000 Lbs bomb. The distinct blast mitigation effect of the proposed structure was demonstrated by adopting various layers/barriers created as protective measures for the strategic structure. The calculated result shows that the blast effect on the structure is potentially reduced due to provision of buster slab with sand cushioning provided as protective measure to the main structure. This concept of layered protective measures may be adopted for safeguarding strategic structures such as Domes, Tunnels and Underground Structures.

• 한국노년학
• /
• 제38권4호
• /
• pp.1107-1125
• /
• 2018

본 연구는 치매환자와 동거하는 가족의 자살생각 위험요인과 보호요인에 따라 유형화를 하고, 각 유형집단이 자살생각에 미치는 영향을 분석하여 자살예방을 위한 실증적 기초 자료를 제시하는데 목적이 있다. 본 연구는 2013년 지역사회건강조사를 활용하여 치매환자와 동거하고 있는 가족 2,715명의 자료를 분석대상으로 하였고, 잠재계층모형분석과 이항로지스틱분석을 실시하였다. 주요분석내용은 (1) 자살생각의 위험요인과 보호요인의 유형화 (2) 유형화된 집단이 자살생각에 미치는 영향을 규명하고자 한다. 총24개의 자살생각 위험요인과 보호요인의 지표를 활용하여 잠재적 집단분석을 실시하여 '고위험-저보호요인'집단, '고위험-고보호요인'집단, '저위험-고보호요인'집단, '저위험-저보호요인'집단으로 유형화하였다. 분석 결과, '고위험-저보호요인'집단인 경우 자살생각이 가장 높았고, 유의하게 자살생각을 가지는 것으로 나타났다. 결과에 기반한 실천적 함의와 과제를 제시하였다.

• 경영과학
• /
• 제17권1호
• /
• pp.17-30
• /
• 2000

This paper addresses the effect of protective capacity on the lead time and throughput of a re-entrant line where statistical fluctuations exist in the form of variation in processing times and machine breakdowns. The specific framework employed in the paper is a five station re-entrant line structured as a closed network mode. This paper argues that protective capacity can be used in conjunction with WIP inventory in order to reduce the lead time and to increase the increase the throughput of a line. Simulation analyses are included to give insight into the effectiveness of protective capacity.

• Preventive Nutrition and Food Science
• /
• 제10권1호
• /
• pp.46-51
• /
• 2005

The protective effect of Acanthopanax senticosus (AS) extract on alloxan-induced pancreatic β-cell damage was investigated in HIT T-15 cells, a Syrian hamster pancreatic β-cell line. Alloxan caused the pancreatic β-cell damage through the generation of reactive oxygen free radicals, increased DNA fragmentation, and decreased cellular NAD/sup +/ levels. The β-cell damage was significantly prevented by the pretreatment with water soluble extract of AS roots. These results suggest that the protective effect of AS extract, on alloxan-induced β-cell damage, is primarily due to the inhibition of the generation of reactive oxygen free radical species (ROS) by alloxan.

• Journal of Microbiology and Biotechnology
• /
• 제26권5호
• /
• pp.823-828
• /
• 2016

The present study investigated the protective effect of naturally purified 4-(3,4-dihydroxyphenyl)-3-buten-2-one (DHP) from Phellinus linteus against naproxen-induced gastric antral ulcers in rats. To verify the protective effect of DHP on naproxen-induced gastric antral ulcers, various doses (1, 5, and 10 μg/kg) of DHP were pretreated for 3 days, and then gastric damage was caused by 80 mg/kg naproxen applied for 3 days. DHP prevented naproxen-induced gastric antral ulcers in a dose-dependent manner. In particular, 10 μg/kg DHP showed the best protective effect against naproxen-induced gastric antral ulcers. Moreover, DHP significantly attenuated the naproxen-induced lipid peroxide level in gastric mucosa and increased the activities of radical scavenging enzymes, such as superoxide dismutase, catalase, and glutathione peroxidase, in a dose-dependent manner. A histological examination clearly demonstrated that the gastric antral ulcer induced by naproxen nearly disappeared after the pretreatment of DHP. These results suggest that DHP can inhibit naproxen-induced gastric antral ulcers through prevention of lipid peroxidation and activation of radical scavenging enzymes.

• 한국수산과학회지
• /
• 제50권5호
• /
• pp.520-526
• /
• 2017

Carnosine was recently reported to protect against the DNA damage induced by oxidative stress. In this study, we investigated the protective effect of eel Anguilla japonica carnosine extracts prepared using different methods (heat treatment extracts, HTEs; ion exchange chromatography, IEC; ultrafiltration permeation, UFP) on leukocyte DNA damage using the comet assay. Human leukocytes were incubated with extracts of eel carnosine at concentrations (of 10, 50, $100{\mu}g/mL$), and then subjected to an oxidative stimulus [$200{\mu}M$ hydrogen peroxide ($H_2O_2$)]. Pretreatment of the cells for 30 min with carnosine significantly reduced the genotoxicity of $H_2O_2$ measured as DNA strand breaks. The protective effects of the three types of extract (HTE, IEC, and UFP) increased with concentration. At the highest concentration (100 g/mL). there were no statistical differences in oxidative damage between each extract treatment and PBS-treated negative controls. When leukocytes were incubated with carnosine for 30 min after exposure to $H_2O_2$. the protective ability of each extract changed. Therefore, eel carnosine inhibits the $H_2O_2$ induced damage to cellular DNA in human leukocytes, supporting the protective effect of this compound against oxidative damage.

• 대한한방내과학회지
• /
• 제31권1호
• /
• pp.84-101
• /
• 2010

Objectives : This study aimed to evaluate the protective effects of Seonpyejeongcheon-tang (SJT) on elastase-induced lung injury. Materials and Methods : The extract of SJT was treated to A549 cells and an elastase-induced lung injury mouse model. Then, various parameters such as cell-based cytoprotective activity and histopathological findings were analyzed. Results : SJT showed a protective effect on elastase-induced cytotoxicity in A549 cells. This effect was correlated with analysis for caspase 3 levels, collagen and elastin contents, protein level of cyclin B 1, Cdk1, and Erk1/2, and gene expression of TNF-$\alpha$ and IL-$1{\beta}$ in A549 cells. SJT treatment also revealed a protective effect on elastase-induced lung injury in mouse model. This effect was evidenced via histopathological findings, including immunofluoresence stains against elastin, collagen, and caspase 3, and protein levels of cyclin B1, Cdc2, and Erk1/2 in lung tissue. Conclusion : These data suggest that SJT has pharmaceutical properties on lung injury. This study thus provides scientific evidence for the efficacy of SJT for clinical application to patients with chronic obstructive pulmonary disease.

• Preventive Nutrition and Food Science
• /
• 제5권4호
• /
• pp.225-229
• /
• 2000

The antioxidative and protective activities of kefir, low-fat dry milk (NFDM) extract and fractions on SFME cells in serum-free medium were investigated. Kefir and low-fat kefir and NFDM extract were made by solubilizing the freeze dried powder forms in deionized water, filtering through glass prefilter, 12 ㎛ and 2 ㎛ membrane, and demineraling with chelating resin. Kefir, low-fat kefir and NFDM extract were fractioned into dialyzate and retentate by dialysis with membrane tube having the molecular cut-off of 3,500 Dalton. An antioxidative activity was analyzed by the in vitro model system using a linoleic acid. In the case of kefir an antioxidative activity was detected only in the retentate of kefir extract. On the other hand NFDM showed an antioxidative activity in extract, demineralized extract, dialyzate and retentate. The retentate of kefir extract had the higher antioxidative activity than that of NFDM extract. Kefir showed the protective effect of SFME cells in serum-free medium in extract, demineralized extract and retentate, but low-fat kefir didn't. NFDM had the similar protective effect on SFME cells as extract, demineralized extract and retentate of kefir.

• 농업과학연구
• /
• 제38권4호
• /
• pp.625-629
• /
• 2011

To investigate the protective effect of eggplant (Solanum melongena L.) and its active compound, delphinidin, we used in vitro and cellular system. The active fraction from eggplant, BuOH fraction, showed protective effect from hydrogen peroxide-induced oxidative stress in WI-38 fibroblast cells. It suggests that eggplant would have the protective activity from radical-induced oxidative damage and its BuOH fraction would play the crucial role with antioxidative activity. In addition, delphinidin, the active compound from eggplant, exerted the strong 1,1-diphenyl-2-picrylhydrazyl scavenging effect with $IC_{50}$ value of 6.59 ${\mu}g/mL$. Furthermore, the cellular oxidative stress was induced by 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH) in LLC-$PK_1$ cells, while treatment of delphinidin atteunated AAPH-induced oxidative stress as dose-dependent manner. The present study suggests the antioxidative activity of eggplant and delphinidin against free radical-induced oxidative stress.

• Biomolecules & Therapeutics
• /
• 제2권4호
• /
• pp.326-330
• /
• 1994

The treatment of pseudomonal infection is a perplexed problem because of its modest susceptibility to most of the major antibiotics. A novel Pseudomonas vaccine(CFC-101) was prepared from the outer membrane protein fractions of several Pseudomonas strains. In this study, we examined CFC-101's effectiveness in both active and passive immunization models. CFC-101 in mice at 0.2 mg/kg, i.p., given three times at two-day intervals, completely prevented the death caused by Pseudomonas aeruginosa. Antibody titer, in accordance with the protective effect in this active immunization, was elevated to its peak level following three consecutive administrations of CFC-101. Thereafter, antibody titer stayed at a constantly high level. Each outer membrane protein fraction from the four CFC-101 producers, exhibited good cross-protective effects in mouse infection models against different Fisher types of P. aeruginosa. In the passive immunization model, 21~336 $\mu\textrm{g}$/kg of anti-rabbit IgG to CFC-101, when mice being infected with a challenge strain, prevented the Pseudomonhas-induced death up to 60%. Therefore, the preventive effect of CFC-101 was verified in both the active and passive immunization models.