• Journal of dental hygiene science
• /
• v.6 no.3
• /
• pp.153-158
• /
• 2006

Bleaching of vital and nonvital teeth is becoming a more commonly used treatment in the dental office and at home. To improve appearance and remove discoloration, the teeth of specific patients are treated with a variety of bleaching agents. The typical bleaching agents contains carbamide or hydrogen peroxide as the active component. The purpose of the review article was to summarize and discuss the available information concerning the effect of peroxide releasing bleaching agent on dental restorative materials and restorations. Information from all original scientific full papers or reviews listed in PubMed or ISI Web Science were included in the review. Bleaching may exert a negative influence on restorations and restorative materials. Advice is provided based on the current literature to minimize the impact of bleaching treatment on restorative materials and restorations.

• Journal of Radiation Protection and Research
• /
• v.41 no.1
• /
• pp.15-29
• /
• 2016

Research background: Despite the visible growth in radiation usage and nuclear power development, the analysis of their relationship with fundamental rights, a subject of public concern regarding issues including the right to health, environmental rights, safety rights, the right to know, the right to development, and the right to life, is currently non-existent. Methods: By examining various fundamental rights in the context of positive laws regarding radiation and nuclear power in an idealistic perspective that guarantees the maximum degree of rights, this paper aims to propose legislative supplements that will lead to improvements in quality of life. Result and discussion: In the South Korean Constitution, radiation and nuclear power is a subject incorporating several rights, including at least 12 clauses that are directly related to fundamental rights; these constitutional rights are manifested in the various clauses of the 14 positive laws regarding radiation and nuclear power. The question on the relative importance of each fundamental right as reflected in these positive laws- whether the right to life should be prioritized or considered equal in weight to the right to health, environmental rights, the right to know, and safety rights- requires careful deliberation and is difficult to humanly resolve in the short term. Conclusion: Making policy that expands the usage of radiation and nuclear power while simultaneously preventing their associated risks is an important task for the Republic of Korea, and a proper value judgment is necessary to find a balance in its associated rights.

• Journal of Life Science
• /
• v.27 no.1
• /
• pp.72-77
• /
• 2017

Inorganic iron is essential for various metabolic processes, including RNA synthesis, electron transport, and oxygen detoxification in microorganisms. Many bacterial pathogens compete for iron acquisition in diverse environmental condition such as host. Salmonella Typhimurium SL1344 also requires inorganic iron as a cofactor for growth. When a M9 minimal liquid medium was supplemented with ethylenediamine di-o-hydroxyphenylactic acid (EDDA) which acts as an iron-chelating agent, growth of Salmonella Typhimurium SL1344 in the supplemented medium was completely arrested by deficient of useful iron under iron-depleted condition. However, a number of siderophores, which are small, high-affinity iron chelating compounds secreted by microorganisms such as bacteria and fungi, were produced for utilization of restricted iron under iron-depleted condition. A M9 minimal liquid medium complemented with human transferrin (hTf)-iron complex turned completely off production of siderophores, but growth of Salmonella Typhimurium SL1344 maintained level similar to compare one complemented with iron (III) chloride (FeCl3). This means that human transferrin (hTf)-bound iron can utilize via directly interaction with Salmonella Typhimurium SL1344 without productions of siderophores. Through construction and analysis of negative mutant for utilization of human transferrin (hTf)-bound iron, we confirm that the bacterium can directly use human transferrin (hTf)-bound iron without extracellularly intermediated carriers such as siderophores.

• Journal of Food Hygiene and Safety
• /
• v.35 no.3
• /
• pp.219-224
• /
• 2020

The purpose of this study was to provide basic data necessary for the prevention of food poisoning and safe food management. We examined 872 food samples for B. cereus in accordance with the MFDS Food Code and investigated characteristics of their harboring toxin genes. We detected and isolated 113 strains of B. cereus from 78 food samples (8.9%), and the average detection level was 48 CFU/g. B. cereus isolates carried at least 1 toxin gene among the emetic toxins and 5 enterotoxin genes. The toxin gene profiles of B. cereus were classified into 18 different types of isolates showing genetic diversity. Among the strains, 34 (30.1%) had all 5 enterotoxin genes (Cytk-nheA-entFM-bceT-hblC), accounting for the highest percentage. The entFM and nheA genes were major enterotoxin genes, while the emetic toxin gene, CER, was the least detected in B. cereus isolated from food samples.

• Korean Journal of Food Science and Technology
• /
• v.38 no.6
• /
• pp.805-809
• /
• 2006

Ozonized olive oil was tested for its mutagenic potential in a Salmonella/microsome assay. Additionally, antimicrobial activity was tested against Propionibacterium acnes, Staphylococcus epidermidis, Staphylococcus aureus and Pseudomonas aeruginosa, pathogenic strains related to acne, using the paper disk and agar dilution method. Ozonized olive oil showed antimicrobial activities against all the strains tested, with minimal inhibitory concentrations (MICs) values in a range of 2${\sim}$10 mg/mL. Mutagenicity of ozonized olive oil was evaluated with Salmonells typhimurium TA98, TA100 and Ta1535, with and without addition of S9 mixture. No increase in the number of $his^{+}$ revertants over the negative control (solvent and non-ozonized olive oil) values was observed with TA98 (1,000 ${\mu}g/plate$), TA100 (1,500 ${\mu}g/plate$) and TA1535 (1,500 ${\mu}g/plate$) strains. The results from this study suggested that ozonized olive oil does not show any mutagenic potential.

• Korean Journal of Biological Psychiatry
• /
• v.2 no.1
• /
• pp.100-106
• /
• 1995

Antibodies to hepatitis C drew attention because of high morbidity to chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. HCV was known to be transmitted by transfusion, sexual behavior and parenteral drug use. However, some kind of autoimmune mechanism was suggested to be involved in the genesis of HCV-induced liver diseases. We hypothesized the prevalence of having anti-HCV might be higher in psychiatric patients rather than general population because of the characteristic route of transmission. Using Abbott HCV BA kit, anti-HCV was detected in the sera of 113 psychiatric inpatients from early December in 1992 to late May in 1994. The Positivity of anti-HCY was significantly(P<0.05) higher among psychiatric inpatients(10.6%) than in healthy controls(3.0%). There were no disease specificity among psychiatric inpatients who had anti-HCV, though alcoholics tended to have more anti-HCV. We couldn't find any significant correlation of anti-HCV with age, seasons of birth, lymphocytes (%) and liver function.

• Korean Journal of Microbiology
• /
• v.39 no.2
• /
• pp.76-82
• /
• 2003

To prepare evolved PHB depolymerase with increased activity for PHB or P(3HB-co-3HV) compared to the activity of the original PHB depolymerase from Alcaligenes faecalis T1, random mutation of the cloned PHB depolymerase gene was performed by using a DNA shuffling method. A library of mutated PHB depolymerase genes from A. faecalis T1 was fused to the ice nucleation protein (INP) gene from Pseudomonas syringae in pJHCl 1 and approximately 7,000 transformants were isolated. Using M9 minimal medium containing PHB or P(3HB-co-3HV) as the carbon source, mutants showing alteration in PHB depolymerase activity were selected from the transformants. The PHB depolymease activity of the transformants was confirmed by the formation of halo around colony and the turbidity decrease tests using culture supermatants. The catalytic activity of PHB depolymerase of the best mutant II-4 for PHB or P(3HB-co-13 mol% 3HV) was approximately 1.8-fold and 3.2-fold, respectively, higher than that of the original PHB depolymerase. DNA sequence analysis revealed that three amino acid residues (Ala209Val, Leu258Phe, and Asp263Thr) were substituted in II-4. From the mutational analysis, it was presumed that the substitution of amino acids near catalytic triad to more hydrophobic amino acids enhance the catalytic activity of PHB depolymerase from A. faecalis T1.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.43 no.3
• /
• pp.320-326
• /
• 2016

The fracture of a needle during local anesthesia in dental treatment is rare; however, when it occurs, the needle should be removed without damage to surrounding structures as soon as possible. A fractured needle fragment that is buried in soft tissue would be difficult to remove, and a careful surgical procedure under general anesthesia is recommended in such cases. Children who require dental treatment are often not capable of cooperative behavior, thus unexpected movements can increase the risk of needle fracture. Clinicians can reduce the incidence of needle fracture accidents with a few precautions. In the present case report, we report a case of needle fracture due to abrupt movement during inferior alveolar nerve block anesthesia in a young child, with the purpose of drawing attention to needle fracture incidents. This report describes the possible causes and prevention methods of local anesthetic needle fracture, and the localization methods and surgical procedure for needle fragment removal.

• Korean journal of communication and information
• /
• v.58
• /
• pp.106-129
• /
• 2012

Social Network Service(SNS), which are an emerging form of political architecture, have been a political means to promote civic engagement and shape pubic opinions on social issues. Along with the influence of SNSs, the governmental control on the dissemination of information over SNSs has increased more and more. It would be ideal if the autonomous governance regulates SNSs which facilitate the networks of the dispersed people. It is the fact, though, that compulsory regulations under which the government controls impose policy and legal restrictions on political expressions. The current study addresses expressive and participatory nature embedded in technological characteristics of SNSs and discusses the problems of content regulations of political expression over SNSs. First of all, it is analyzed that light touch regulation or light touch monitoring should be applied to regulating content on SNSs, particularly political expressions. Constitutional Court proclaimed that legal restrictions on the Internet could infringe basic rights of the people and thus under unambiguous standards, the Doctrine of Clear and Present Danger should be applied to its content. Second, it is found that clarifying the definition of illegality in the application of legal restrictions is necessary to minimize the excessive misleading. Third, it is required that Korea Communications Standards Commission under the government control needs to change in determining the scope of illegal information. In a domestic level, there needs to be safeguards for the protection of the self-regulatory organization such as KISO to guarantee voluntary and autonomous regulatory practices.

• The Korean Journal of Air & Space Law and Policy
• /
• v.20 no.2
• /
• pp.235-251
• /
• 2005

German working hour law of 1994(Arbeitszeitgesetz) provides maximum working hour as 8 hours a day and 48 hours per week. The law provides that minimum 11 hours rest-time is required between the end of a day's work and the beginning of the next day's work. Namely, the hour that the workers are put under commanding of the user is restricted within 13 hours per day. In the meantime, article 5, 7, 14, and 15 of the law have some letting the exceptional provisions regarding the working hour and rest-time of flight crew, and 2nd administrative order for the aviation transportation business owner, which is established based on such exceptional provisions(2.DV LuftBO), provides the working hour and rest-time of flight crew quite in detail. The administrative order is detailed quite regarding block time, flight working hour, and rest-time. So, it does not need to interpret additionally. Airlines in Korea should observe the both Labor Standard Act applying to general workers and Aviation Act focused on flight crew, so it is difficult that airlines manages working hour and rest-time of the flight crew efficiently. Therefore, it is desirable that our country refers to and considers adopting this legislation method of Germany which regulates working hour and rest-time of flight crew in detail in the 2.DV LuftBO.