• Archives of Pharmacal Research
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• v.19 no.5
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• pp.416-422
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• 1996

Twenty one phenylacetylshikonin analogues were synthesized from various subsitituted phenyl acetic acids and their cytotoxicity values against A549, K562 and L1210 cell lines and antitumor action in mice bearing S-180 cells were measured. All of phenylacetylshikonin analogues expressed a potent cytotoxicity $(ED_{50}, 0.1-1.80{\mu}g/ml)$ against L1210 and K562 cells. L1210 cells were the most sensitive to shikonin analogues among these cells. Except 4-methosyphenylacetylshikonin $(0.098 {\mu}g/ml)$, and a-acetoxyphenylacetylshikonin $(0.10 {\mu}g/ml)$, all other shikonin derivatives sshowed higher $ED_{50}$ values than phenylacetylshikonin $(0.13{\mu}g/ml)$, in L1210. In K562 cell, a-substitution of phenylacetylshikonin $(0.1{\mu}g/ml)$, while other subsitutions increased it slightly; 4-methoxyphenylacetylshikonin $(0.033{\mu}g/ml)$ showed a exceptionally good cytotoxicity against K562 cell. 4-Halogenation tended to decrease the cytotoxic effect on L1210 cells, while it enhanced the effect on K562; 4-bromophenylacetyl $$[ED_{50};(L1210)=1.76{\mu}g/ml, ;ED_{50};(K 562)=0.32 {\mu}g/ml]$$ and 4-chlorophenylacetyl shikonin $$[ED_{50};(L1210)=1.64 {\mu}g/ml, ;ED_{50};(K562)=0.32 {\mu}g/ml]$$. In contrast, A549 cells were much less sensitive to these shikonin analogues which showed $ED_{50}$ values of$1.5-1.35 {\mu}g/ml)$.Most of phenylacetylshikonin derivatives showed good antitumor activity in mice bearing S-180 cells. a-A-cetoxyphenylacetylshikonin and 4-dimethylaminophenylacetylshikonin showed highest T/C value (192-195%), implying that introduction of a-acetyl or of 4-dimethylamino group enhanced the antitumor activity as shown for 4-dimethylaminophenylacetylshikonin (T/C, 192%). It might be due to improvement of water solubility by dimethylamino group in the molecule.

• Microbiology and Biotechnology Letters
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• v.10 no.1
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• pp.53-58
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• 1982

In order to obtain anticancer substances from natural products, extracts of dry herbs, which have long been used to treat cancer or canter-like diseases in oriental countries, were screened. Extracts were made with hot water and/or organic solvents. With the extracts we treated murine leukemic L1210 cells growing in Fischer's medium. After 48 hours of incubation, cells were counted and concentrations of dry extracts to achieve 50 percent inhibition of the control growth, ED$_{50}$ values, were determined. Among the 38 species of medicinal plants tested, water extracts of six species showed ED$_{50}$ values of substantially low. Further extraction with organic solvents could reduce their ED$_{50}$ values within the range of the NCI quality control limit. The promising species as potential sources of anti-cancer substances included Cinnamomum cassia, Citrus trifoliata, Coptis japonica, Panax ginseng, Phellodendron amurense, and Scutellaria baikalensis.

• Journal of the Korea Society of Computer and Information
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• v.29 no.1
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• pp.1-9
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• 2024

This paper proposes an integration of the ED-H scheduling algorithm, known for optimal real-time scheduling, with the LoRaEnergySim simulator. This integration facilitates the simulation of interactions between real-time scheduling algorithms for tasks with time constraints in Class-A LoRaWAN Class-A devices using a super-capacitor-based energy harvesting system. The time and energy characteristics of LoRaWAN status and state transitions are extracted in a log format, and the task model is structured to suit the time-slot-based ED-H scheduling algorithm. The algorithm is extended to perform tasks while satisfying time constraints based on CPU executions. To evaluate the proposed approach, the ED-H scheduling algorithm is executed on a set of tasks with varying time and energy characteristics and CPU occupancy rates ranging from 10% to 90%, under the same conditions as the LoRaEnergySim simulation results for packet transmission and reception. The experimental results confirmed the applicability of co-simulation by demonstrating that tasks are prioritized based on urgency without depleting the supercapacitor's energy to satisfy time constraints, depending on the scheduling algorithm.

• Journal of Animal Science and Technology
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• v.49 no.1
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• pp.15-24
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• 2007

The purpose of this study was to evaluate the presence and differential expression of connexin isoforms in the efferent ductules (ED) of male rat reproductive tract during postnatal development. Total RNA was isolated from the ED collected from rats at 1 week, 2 weeks, 1 month, 3 months, and 6 months of ages. Expression of six connexin mRNAs of 14 isoforms tested was detected by semi-quantitative RT-PCR. Fluctuation of mRNA levels of connexins 26 and 30 was found according to ages. A significant decrease of connexin 31.1 mRNA level was observed in the ED at 1 month of age. The highest levels of connexin 37 and 45 mRNAs were detected in the ED of early developmental period, while the expression of connexin 43 was the lowest at 1 week of age. The present study demonstrates differential regulation on expression of connexin isoforms in the rat ED in age-dependent manner.

• Journal of Korean Clinical Nursing Research
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• v.14 no.2
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• pp.83-92
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• 2008

Purpose: This study was done to identify the relationship between experiences of violence, and burnout and job satisfaction of emergency department (ED) nurses and to provide basic information to improve quality of life for nurses and quality of nursing care by increasing the ability of nurses to deal with violent situations and thus, improve job satisfaction. Method: Participants (n=153) were recruited in S and B cities from October 16 to December 22, 2007. Descriptive statistics, t-test, ANOVA, and Pearson correlation coefficient were used to analyze the data. Results: Level for ED nurse burnout was 2.54 out of a possible 4, and for ED nurse job satisfaction, 2.81 out of a possible 5. There were significant differences according to sex (t=-3.217, p=.002), total clinical career (F=5.805, p<.05), and clinical career in the ED (F=1.640, p<.01). There was a significant positive correlation between violence experience and burnout (r=.500, p<.001), and significant negative correlations between violence experience and job satisfaction (r=-.300, p<.001), and between burnout and job satisfaction (r=-.492, p<.001). Conclusion: The findings from this study indicate that experiences of violence in the ED decrease work efficiency of the nurses and increase burnout. So, it is important to reduce occurrences of violence in ED and to prepare programs for dealing with violence and providing emotional support in cases of violence directed at nurses.

• Korean Journal of Occupational Health Nursing
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• v.27 no.1
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• pp.59-66
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• 2018

Purpose: This study aimed to identify the effect of role conflict, self-efficacy, and resilience on the nursing task performance of emergency department (ED) nurses. Methods: Data were collected from 140 ED nurses working in 6 general hospitals, using self-reporting questionnaires. Data were analyzed using SPSS 23.0, and the analyses included descriptive statistics, a t-test, an ANOVA, the Pearson's correlation coefficient test, and a stepwise multiple regression. Results: Nursing task performance differed significantly in terms of the following general characteristics of the participants: age, marital status, total clinical experience, clinical experience in the ED, and position at the hospital. Nursing task performance was positively correlated with role conflict, self-efficacy, and resilience. Self-efficacy, role conflict, clinical experience in the ED, and resilience were significant predictors of nursing performance, and they accounted for 36.9% of the variance. Conclusion: Self-efficacy was identified as the most significant factor affecting the nursing task performance of ED nurses. Therefore, it is necessary to develop programs to improve the self-efficacy of ED nurses.

• Journal of Trauma and Injury
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• v.37 no.1
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• pp.20-27
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• 2024

Purpose: Severe abdominal injuries often require immediate clinical assessment and surgical intervention to prevent life-threatening complications. In Jeju Regional Trauma Center, we have instituted a protocol for emergency department (ED) laparotomy at the trauma bay. We investigated the mortality and time taken from admission to ED laparotomy. Methods: We reviewed the data recorded in our center's trauma database between January 2020 and December 2022 and identified patients who underwent laparotomy because of abdominal trauma. Laparotomies that were performed at the trauma bay or the ED were classified as ED laparotomy, whereas those performed in the operating room (OR) were referred to as OR laparotomy. In cases that required expeditious hemostasis, ED laparotomy was performed appropriately. Results: From January 2020 to December 2022, 105 trauma patients admitted to our hospital underwent emergency laparotomy. Of these patients, six (5.7%) underwent ED laparotomy. ED laparotomy was associated with a mortality rate of 66.7% (four of six patients), which was significantly higher than that of OR laparotomy (17.1%, 18 of 99 patients, P=0.006). All the patients who received ED laparotomy also underwent damage control laparotomy. The time between admission to the first laparotomy was significantly shorter in the ED laparotomy group (28.5 minutes; interquartile range [IQR], 14-59 minutes) when compared with the OR laparotomy group (104 minutes; IQR, 88-151 minutes; P<0.001). The two patients who survived after ED laparotomy had massive mesenteric bleeding, which was successfully ligated. The other four patients, who had liver laceration, kidney rupture, spleen injury, and pancreas avulsion, succumbed to the injuries. Conclusions: Although ED laparotomy was associated with a higher mortality rate, the time between admission and ED laparotomy was markedly shorter than for OR laparotomy. Notably, major mesenteric hemorrhages were effectively controlled through ED laparotomy.

• Communications for Statistical Applications and Methods
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• v.9 no.2
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• pp.565-576
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• 2002

We propose a new sampling design for the 2001 Health Index Survey at Seoul. In this stratified two-stage sampling design, the ED(enumeration district) of 2000 Population and Housing Census is used as primary sampling unit and the Gu is used as stratification variable in order to obtain the sub-domain estimate for 25 Gu's as well as population estimate for Seoul. The sample ED's are systematically selected after the Ed's are ordered by location and property to obtain a representative sample. And also, the imputation methods for item nonresponses are suggested.

• Applied Chemistry for Engineering
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• v.7 no.1
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• pp.59-66
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• 1996

Novel chitosan beads containing a series of bisamino-terminated polyethylene glycol (Bisamino-PEG, $Jeffamine^{(R)}ED$ series) have been prepared via capillary extrusion method using an alkaline solution. The results of swelling kinetics of chitosan beads showed that as the chain length of PEG in chitosan beads increased, the swelling process of the beads proceeded slowly. In order to study the releasing kinetics quantitatively, fluorescamine was coupled to the pendant amino groups and the releasing processes were followed by UV spectra. The results revealed that the releasing process was retarded in the order of $Jeffamine^{(R)}ED$-600 < $Jeffamine^{(R)}ED$-900 < $Jeffamine^{(R)}ED$-2001 as the chain length of PEG was increased. The slow release of PEG from the beads is considered to be governed by the chain length of PEG and interpolymeric hydrogen bonding between PEG and the chitosan molecule.

• Journal of Korean Society on Water Environment
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• v.33 no.3
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• pp.334-340
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• 2017

A pilot-scale electrodialysis system was designed and constructed to treat groundwater polluted with arsenic and manganese. Synthetic groundwater, in which some amount of arsenic and manganese was added to make 500 mg/L of Mn and $50{\mu}g/L$ of As, was used as a feed for the ED system. The limiting current density, linear water velocity, applied voltage, and membrane surface area were investigated to obtain efficient and economic operation of the ED system. The linear water velocity was increased 0.74 cm/s to 11 cm/s based on evaluation of limiting current density. The water quality of diluate for 85 minutes of operation was satisfied with water quality criteria for drinking water using the ED system with 14 pairs of ion exchange membranes. The increased membrane pairs to 21 and 42 pairs were very effective to reduce conductivities of the diluate. The operation cost of the ED system was assessed using specific energy consumption, which was $1.065{\sim}1.2kWh/m^3$. Considering low salt concentrations of the groundwater, improvement of the ED system are required to increase current utilization and to apply low voltage while the ED system was applicable to produce drinking water.