• Journal of the Korea Organic Resources Recycling Association
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• v.29 no.4
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• pp.5-13
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• 2021

Ammonia, primarily originating from urinary urea of the livestock manure, is known to play as a major precursor of fine particulate matter (PM2.5) generation which leads to a decrease in air quality and to harmful effects on public health. The objective of this study was to evaluate the effect of acetohydroxamic acid (AHA) addition on inhibition of ammonia conversion from urea. The experiment was performed at different urea concentration (500-4,000 mg Urea-N/L), AHA concentration (0-4,000 mg AHA/L), pHs (pH 6-10), and temperature (10-35℃). The result showed that the urease inhibition efficiency increased at higher concentration of AHA. However, the specific urease inhibition activity decreased at higher pH, showing 867.1±6.7 Unit/g AHA at pH 6 and 1,167.9±17.4 Unit/g AHA at pH 10, respectively. Decreased urease inhibition efficiency at both AHA and control was observed at higher temperature. This finding indicates that AHA can be used as the urease inhibitor for reducing ammonia emission in the management of livestock manure.

• Korean Chemical Engineering Research
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• v.51 no.3
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• pp.403-406
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• 2013

This paper describes a simple route to synthesis of water-dispersible monodisperse maghemite (${\gamma}-Fe_2O_3$) nanocrystals using 6-aminohexanoic acid (AHA) as a stabilizer. The water-dispersible ${\gamma}-Fe_2O_3$ nanocrystals with an average size of 5 nm were obtained simply by addition of $Fe(CO)_5$ into an octyl ether solution containing AHA at $195^{\circ}C$ under argon condition. As-prepared AHA coated ${\gamma}-Fe_2O_3$ nanocrystals exhibited highly crystallinity and magnetic property while keeping a good dispersity in an aqueous phase. We also obtained water-dispersible AHA coated ${\gamma}-Fe_2O_3$ nanocrystals using ligand-exchange method, demonstrating that AHA can be a good candidate for preparing water-dispersible uniform metal oxide nanocrystals.

• Korean Journal of Clinical Laboratory Science
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• v.54 no.2
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• pp.163-166
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• 2022

Acquired hemophilia A (AHA) is an uncommon autoimmune bleeding disorder in which autoantibodies that affect the functions of factor VIII (FVIII) are present in the blood. The initial diagnosis of AHA is difficult as the presentations of AHA differ from those of congenital hemophilia A. Moreover, the treatment of AHA is more complex due to the presence of autoantibodies against FVIII. Here, we present a case report of postpartum AHA, to increase the perception and knowledge regarding the recognition and management of such cases. We present a young female with the chief complaint of vaginal bleeding and upper arm ecchymosis. Laboratory results exhibited isolated prolonged activated partial thromboplastin time (APTT) and FVIII inhibitors. The patient was treated with corticosteroids, FVIII concentrates, and a bypassing agent. In conclusion, unexplained postpartum bleeding, unmanageable with basic hemostatic measures, should lead to clinical suspicion of an acquired bleeding disease.

• Transactions of the Korean hydrogen and new energy society
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• v.22 no.2
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• pp.184-190
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• 2011

The membrane properties (membrane resistance and ion exchange capacity) of the five types of commercial anion exchange membrane, i.e. IOMAC, AHT, APS, AHA, AFN, were evaluated for the application in the alkaline electrolysis. The membrane resistance decreased in the order; in 1M KOH: AHT>IOMAC>AHA>AFN>APS; in 1M NaOH: AHT>IOMAC>AHA>APS>AFN. The ion exchange capacity decreased in the order: AFN>APS>AHT>AHA>IOMAC. The membrane life was determined from the change of membrane resistance in 1M KOH and NaOH with an increase of soaking time in 20 wt% KOH and 30 wt% NaOH solution. AHA membrane had a good membrane life in 20 wt% NaOH with its unchanged membrane resistance. And, AFN and AHA membrane had a good membrane life in 30 wt% NaOH with its unchanged membrane resistance.

• Clinical and Experimental Reproductive Medicine
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• v.22 no.2
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• pp.183-189
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• 1995

In human IVF-ET, the development and morphology of the embryo have been known to affect implantation and pregnancy rates(PRs). Recently, pregnancy has been reported to related to the embryos with thick zona-pellucida, high levels of fragmentation, poor blastomere development and zona hardening. Although the mechanism of implantation is unclear, it is thought that the hatching process precedes implantation and that the hatching is related to implantation and PRs. This study was carried out to investigate the effect of assisted hatching(AHA) on the improvement of PRs in human IVF-ET. The results were as follows; 1. The PRs of the AHA group (40.8%) was significantly higher than that of control group(27.2%)(P<0.01). 2. According to the age of patients, the PRs of control and AHA groups were 33.9%(20/59), 44,4%(12/27) in <30 yrs, 26.1%(30/115), 38.3%(18/47) in 31-35 yrs, 22.4%(13/58), 41.4%(12/29) in >36 yrs, respectively. 3. According to the factors of infertility in AHA group, unexplained(immunologic factor) (40.0%) and male factors(41.9%) were higher than female(tubal obstruction, endometriosis, adhesion) factor (28.9%). As a result, it is suggested that AHA technique improve the PRs in poor prognosis patients. It is concluded that AHA method can be used to improve the PRs in human lVF-ET.

• Korean Journal of Clinical Pharmacy
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• v.25 no.3
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• pp.200-208
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• 2015

Objective: Patients with acute coronary syndrome (ACS) are typically managed with dual antiplatelet therapy of acetylsalicylic acid (aspirin) and $P2Y_{12}$ receptor inhibitor. In this study, we discussed current and previous antiplatelet therapy guidelines and compared with guidelines of the USA (ACC/AHA), Europe (ESC) and Korea (KSC). Method: This study investigated from ACC/AHA Joint Guidelines (the USA), ESC Clinical Practice Guidelines (Europe) and Korea Society of Interventional Cardiology (Korea) web site, respectively. Results: It is significant that difference between the current and the previous guidelines was integration of terminology from clopidogrel to $P2Y_{12}$ receptor inhibitors since prasugrel and ticagrelor, new antiplatelet drugs, has been added. The other difference was all three guidelines has differences in dose of aspirin. The most notable difference was class of recommendation(COR) in $P2Y_{12}$ receptor inhibitors. ACC/AHA and Korean guidelines recommend clopidogrel, prasugrel, and ticagrelor with COR IB; whereas, ESC recommend prasugrel and ticagrelor with IB which is higher than clopidogrel with IC. Conclusion: This research addresses important movement to revise the Korean existing guideline recommendations. New Korean antiplatelet therapy guideline should be avoiding obvious differences in ACC/AHA and ESC guidelines and harmonizing international guidelines.

• Clinical and Experimental Pediatrics
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• v.48 no.2
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• pp.165-173
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• 2005

Purpose : We performed the study to evaluate the value of the follow-up echocardiogram performed 6 months to 1 year after the onset of Kawasaki disease(KD), as recommended by American Heart Association(AHA) guidelines, when echocardiograms in the convalescent period were normal. Methods : Patients were selected from 147 cases diagnosed with KD at Pusan Paik hospital from January 2000 to October 2003. A total of 45 KD patients belonged to AHA risk level I and II were performed follow-up echocardiography. The patient's medical records and echocardiogram were reviewed. Additionally, we sought the opinion of pediatric cardiologists on the subject by means of a multiple-choice survey. Results : 37 children were belonged to AHA risk level I and the remaining 8 patients were belonged to risk level II. Of these 45 children, none were noted to have abnormalities on later follow-up echocardiogram. In the results of questionnaire, 37 percent of the participants advocate no follow-up after convalescent period for risk level I, and 33.3 percent favor periodic follow-up with echocardiography for risk level II up to one year. But there were no consensus about the diagnostic criteria of coronary abnormalities and how to follow-up these patients. Conclusion : All children with KD should have an echocardiogram at present and a follow-up study 6 to 8 weeks after the onset of fever. However, additional echocardiographies are not justified if the 6- to 8-week follow-up echocardiogram is normal. We would recommend that the more reasonable diagnostic criteria for coronary abnormalities and the Korean guidelines for long-term cardiovascular management and follow-up of KD need to be established.

• Journal of Korea Foundry Society
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• v.1 no.2
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• pp.10-18
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• 1981

In this paper tensile strength and fatigue propagation rate were investigated by aging treatment $(T_6)$ and thermomechanical treatment (TMT) of 7075-Al Alloy specimen. The results of teat showed that TMT improved tensile strength and fatigue crack propagation due to bomogenization of microstructure. In TMT, the results of comparison between T-H' AHA and T-AHA and $T-AH{\cdot}{\cdot}{\cdot}$and $T-HA{\cdot}{\cdot}{\cdot}$were showed that T-AHA and $T-AH{\cdot}{\cdot}{\cdot}$treatments, after solution treatment, which are aging treated before rolling have higher tensile strength. Our investigation on high temperature stability at the Specimen for $T_6$, T-AHA, $T-AH{\cdot}{\cdot}{\cdot}$treatments resulted in rapid reduction of tensile strength over $150^{\circ}C$, but the reduction of tensile strength for specimen of TMT was smoothed than $T_6$.

• Clinical and Experimental Reproductive Medicine
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• v.35 no.3
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• pp.193-202
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• 2008

Objective: To evaluate efficacy of assisted hatching by laser (AHL) and acidified Tyrode solution (AHA) in selected groups of IVF-ET patients who have a poor prognosis. Methods: From February 2006 to September 2006, total of 328 IVF-ET cycles with advanced female age (${\geq}38$ years), recurrent implantation failure (${\geq}3$ cycles), thick zona (${\geq}17{\mu}m$), and/or poor quality of embryo were randomly divided into assisted hatching by acidified Tyrode solution (AHA, n=180) and the assisted hatching using the ZILOS-tk laser (AHL, n=148) groups. Clinical outcomes were analyzed and compared between AHA and AHL group based on the patient characteristics. Results: In all AHL and AHA group, there were no significant differences in pregnancy (42.6%, 63/148 vs. 33.3%, 60/180) and implantation rates (17.4%, 82/470 vs. 16.0%, 89/556) However, in advanced female age group (Group 1), pregnancy (37.0%, 20/54 vs. 18.7%, 14/75) and implantation rates (14.4%, 23/160 vs. 7.1%, 15/210) in AHL group were significantly (p<0.05) higher than those of AHA, although there was no difference in patient parameters of both groups. And, the clinical outcome of groups with recurrent implantation failure (Group 2), thick zona pellucida (Group 3) and poor quality embryo (Group 4) were improved in AHL compared to those of AHA: 43.8% (21/48) and 31.6% (25/79) in Group 2, 43.8% (32/73) and 34.1% (28/82) in Group 3, 25.0% (7/28) and 14.6% (6/41) in Group 4, but no significance. Conclusion: The AHL improved the pregnancy and implantation rates in patients with advanced female age and recurrent implantation failure when compared to outcomes achieved from AHA. Therefore, this AHL technique may be a efficient and safe method for patients with poor prognosis.

• Korean Journal of Microbiology
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• v.44 no.2
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• pp.147-155
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• 2008

The diversity of sulfate reducing bacteria was investigated in different depths of sediments in Lake Sihwa, Korea and Lake Aha, China by PCR amplification, denaturing gradient gel electrophoresis (DGGE) and clone libraries targeting dissimilatory sulfite redectase (dsr) gene. In the analysis of DGGE band patterns, the community compositions of dsr gene in the sediments of both lakes were significantly different whereas bands in all depths of each environment revealed similar patterns. Bands from Lake Sihwa were produced much more than those from Lake Aha, demonstrating a higher diversity of dsr gene in Lake Sihwa. Total 68 clones containing dsr gene were obtained to analyze their sequences. Sequences from the sediment of Lake Sihwa were affiliated to Deltaproteobacteria, the Gram-positive thermophilic sulfate reducers belonging to the genus Desulforomaculum and archaeal thermophilic SRB belonging to the genus Archaeoglobus, whereas sequences from the sediments of Lake Aha were related to genus Desulfotomaculum. Clones retrieved from sediment of Lake Sihwa revealed a higher numbers than those of Lake Aha, demonstrating a higher diversity of dsr gene in Lake Sihwa. Most of clones (59%) were distantly related to the known cultivated SRB with $60\sim65%$ of similarity, which were clustered only the sequences from the environments showed less than 90% similarity. These habitat specific sequences suggested that the clustered dsr sequences represent species or groups of species that were indigenous to these environments. This study showed that these lakes have a specific bacterial communities having dsr gene distinct from those in other environments such as soil and marine ecosystems around the world.