• Journal of Life Science
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• v.28 no.7
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• pp.864-873
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• 2018

There has been increasing attention and research in various nanoparticle applications. Nanoparticles have been used for a variety of purposes in different departments including but not limited to cosmetics, food, machinery, and chemical. A highly sought-after field to use nanoparticles, especially natural or artificial silver nanoparticles (SNPs), is the utilization of their significant antimicrobial properties in daily items such as fabrics, indoor air filters, and, water filtration units where abundant bacterial and fungal growth are inevitable. These applications of SNPs, however, have enabled continuous human exposure and hence paved the way for potential SNP toxicity depending on exposure method and particle size. This potential toxicity has led to researches on safer antimicrobial solutions to be utilized in textile and filtration. In this context, products of natural origin have gained expanding interest due to their eco-friendly, cost-effective, and biologically safe properties along their promising antibacterial and antifungal activities. Natural product-applied fabrics and filters have been shown to be comparable to those that are SNP-treated in terms of ease production, material durability, and antimicrobial efficiency. This article summarizes and assesses the current state of in vitro and in vitro toxicity of SNPs and discusses the potential of natural products as an alternative.

• Journal of the Korean Data and Information Science Society
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• v.28 no.5
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• pp.1153-1165
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• 2017

Structural equation modeling (SEM) is a basic tool for testing theories in a variety of disciplines. A maximum likelihood (ML) method for parameter estimation is by far the most widely used in SEM. Alternatively, two-stage least squares (2SLS) estimator has been proposed as a more robust procedure to address model misspecification. A regularized extension of 2SLS, two-stage ridge least squares (2SRLS) has recently been introduced as an alternative to ML to effectively handle the small-sample-size issue. However, it is unclear whether and when misspecification and small sample sizes may pose problems in theory testing with 2SLS, 2SRLS, and ML. The purpose of this article is to evaluate the three estimation methods in terms of inferences errors as well as parameter recovery under two experimental conditions. We find that: 1) when the model is misspecified, 2SRLS tends to recover parameters better than the other two estimation methods; 2) Regardless of specification errors, 2SRLS produces small or relatively acceptable Type II error rates for the small sample sizes.

• Journal of Life Science
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• v.28 no.6
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• pp.745-752
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• 2018

Melanogenesis is involved in the pigmentation of the hair, eyes, and skin in living organisms. Various signaling pathways stimulated by ${\alpha}-MSH$, SCF/c-Kit, $Wnt/{\beta}-catenin$, nitric oxide and ultraviolet activate melanocyte, leading to melanin production by tyrosinase, tyrosinase-related protein (TRP)-1, and TRP-2 expressed via the microphthalmia-associated transcription factor (MITF). However, the abnormal regulation of melanogenesis causes dermatological issues such as graying hair and vitiligo. Therefore, the activators that promote melanogenesis are crucial for the prevention of graying hair and the treatment of hypopigmentary disorders. Many melanogenesis stimulators have been studied for the development of novel drugs derived from synthesized compounds and natural products. Here, in addition to providing a description of a common signaling pathway in the melanogenesis of graying hair and the vitiligo process for the development of novel anti-hair graying agents, this article reviews natural herbs and the active ingredients that promote melanin synthesis as a pharmaceutical agent for the treatment of vitiligo. In particular, compounds such as Imatinib and Sugen with a stimulating effect on melanogenesis as a side effect of the drugs, are also introduced. Recent advances in research on natural plant extracts such as Polygonum multiflorum, Rhynchosia Nulubilis, Black oryzasativa, and Orysa sartiva, widely known as traditional and medicinal extracts, are also reviewed.

• Membrane Journal
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• v.28 no.1
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• pp.75-82
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• 2018

Forward osmosis (FO) desalination system has been highlighted to improve the energy efficiency and drive down the carbon footprint of current reverse osmosis (RO) desalination technology. To improve the trade-off between water flux and salt rejection of thin film composite (TFC) desalination membrane, thin film nanocomposite membranes (TFN), in which nanomaterials as a filler are embeded within a polymeric matrix, are being explored to tailor the separation performance and add new functionality to membranes for water purification applications. The objective of this article is to develop a graphene nanocomposite membrane with high performance of water selective permeability (high water flux, high salt rejection, and low reverse solute diffusion) as a next-generation FO desalination membrane. For advances in fabrication of graphene oxide (GO) membranes, layer-by-layer (LBL) technique was used to control the desirable structure, alignment, and chemical functionality that can lead to ultrahigh-permeability membranes due to highly selective transport of water molecules. In this study, the GO nanocomposite membrane fabricated by LBL dip coating method showed high water flux ($J_w/{\Delta}{\pi}=2.51LMH/bar$), water selectivity ($J_w/J_s=8.3L/g$), and salt rejection (99.5%) as well as high stability in aqueous solution and under FO operation condition.

• Journal of the Korean Society for information Management
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• v.28 no.2
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• pp.97-115
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• 2011

A large and reliable citation database is necessary to identify and analyze citation behavior of Korean researchers in science and technology. Korea Institute of Science and Technology Information (KISTI) built the Korea Science Citation Database (KSCD), and have provided Korea Science Citation Index (KSCI) and Korea Journal Citation Reports (KJCR) services. In this article, citing behavior of Korean scientists on Korean journals was examined by using the KSCD that covers 459 Korean core journals. This research dealt with (1) statistical numeric information of journals in KSCD, (2) analysis of document types cited, (3) ratio of domestic to international documents cited and ratio of citing different disciplines, (4) analysis on immediacy index, peak time, and half-life of cited documents, and (5) analysis on impact of journals based on KJCR citation indicators. From this research, we could find the immediacy citation rate (average 2.36%), peak-time (average 1.7 years) and half-life (average 5.2 years) of cited journals in Korea. We also found that the average journal self-citation rate is more than 50% in every field. In sum, citing behavior of Korean scientists on Korean journals was comprehensively identified from this research.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.8
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• pp.3945-3951
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• 2016

Background: Whether concurrent chemotherapy treatment is superior to radiotherapy alone as an adjuvant regimen for postoperative cervical carcinoma with risk factors remains controversial. Materials and Methods: A literature search strategy examined Pubmed, Embase, the Cochrane Library, the China National Knowledge Internet Web, the Chinese Biomedical Database and the Wanfang Database. Article reference lists and scientific meeting abstracts were also screened. Controlled trials comparing concurrent chemoradiotherapy versus radiotherapy alone in postoperative cervical cancer were included. The methodological quality of non-randomized controlled trials was evaluated using the Newcastle-Ottawa Scale. Randomized controlled studies were evaluated with the Cochrane handbook. A meta-analysis was performed with RevMan 5.3. Results: A total of 1,073 patients from 11 clinical trials were analysed, with 582 patients in the concurrent chemoradiotherapy group and 491 patients in the radiotherapy group. Hazard ratios (HR) of 0.47 (95% CI 0.31-0.72) and 0.50 (95% CI 0.35-0.72) were observed for overall survival and progression-free survival, indicating a benefit from the additional use of concurrent chemotherapy. Subgroup analyses demonstrated that cervical cancer with high risk factors significantly benefitted from concurrent chemotherapy when examining overall survival (HR 0.44, 95% CI 0.28-0.67) and progression-free survival (HR 0.48, 95% CI 0.33-0.70), but patients with intermediate risk factors showed no benefit from concurrent chemotherapy in overall survival (HR 1.72, 95% CI 0.28-10.41) and progression-free survival (HR 1.09, 95% CI 0.19-6.14). No significant differences were observed for grade 3-4 anaemia (risk ratio (RR) 3.87, 95% CI 0.69-21.84), grade 3-4 thrombocytopenia (RR 3.04, 95% CI 0.88-10.58), grade 3-4 vomiting or nausea (RR 1.71, 95% CI 0.27-10.96), or grade 3-4 diarrhoea (RR 1.40, 95% CI 0.69-2.83). Significant differences were observed for grade 3-4 neutropenia in favour of the radiotherapy group (RR 7.23, 95% CI 3.94-13.26). Conclusions: In conclusion, concurrent chemoradiotherapy improves survival in postoperative cervical cancer with high risk factors but not in those with intermediate risk factors.

• The Journal of Korean Academy of Sensory Integration
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• v.14 no.2
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• pp.33-45
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• 2016

Objective : The purpose of this article is to study the effectiveness of a group occupational therapy for children via systematic review, and to provide clinical evidences. Methods : The systematic review initially included articles in Pubmed, Ovid, RISS, KISS, and DBpia, published until 2014. Total 14 articles have been chosen, using different keyword of each domestic/foreign studies. Selected articles were divided depending on the level of evidence, and eventually been organized into group PICO (Patient, Intervention, Comparison, Outcome). Results : The results indicated that there are more diagnosed children than normal in participants and especially children with sensory integration disorder (28.6%) appeared to be the most common. In intervention, group sensory integrative intervention had the largest frequency, and instruments measuring social skills were used most for analyzing the intervention results. The effectiveness of interventions showing statistically significant results were 40.7% of Total. Conclusion : Group occupational therapy for children should be provided to various diagnosis with widely better quality of interventions providing the enough support for the evidence level.

• Parasites, Hosts and Diseases
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• v.53 no.1
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• pp.35-41
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• 2015

Pyronaridine and artesunate have been shown to be effective in falciparum malaria treatment. However, pyronaridine is rarely used in Hainan Island clinically, and artesunate is not widely used as a therapeutic agent. Instead, conventional antimalarial drugs, chloroquine and piperaquine, are used, explaining the emergence of chloroquine-resistant Plasmodium falciparum. In this article, we investigated the sensitivity of P. falciparum to antimalarial drugs used in Hainan Island for rational drug therapy. We performed in vivo (28 days) and in vitro tests to determine the sensitivity of P. falciparum to antimalarial drugs. Total 46 patients with falciparum malaria were treated with dihydroartemisinin/piperaquine phosphate (DUO-COTECXIN) and followed up for 28 day. The cure rate was 97.8%. The mean fever clearance time ($22.5{\pm}10.6hr$) and the mean parasite clearance time ($27.3{\pm}12.2hr$) showed no statistical significance with different genders, ages, temperatures, or parasite density (P>0.05). The resistance rates of chloroquine, piperaquine, pyronarididine, and artesunate detected in vitro were 71.9%, 40.6%, 12.5%, and 0%, respectively (P<0.0001). The resistance intensities decreased as follows: chloroquine>piperaquine>pyronarididine>artesunate. The inhibitory dose 50 ($IC_{50}$) was $3.77{\times}10^{-6}mol/L$, $2.09{\times}10^{-6}mol/L$, $0.09{\times}10^{-6}mol/L$, and $0.05{\times}10^{-6}mol/L$, and the mean concentrations for complete inhibition (CIMC) of schizont formation were $5.60{\times}10^{-6}mol/L$, $9.26{\times}10^{-6}mol/L$, $0.55{\times}10^{-6}mol/L$, and $0.07{\times}10^{-6}mol/L$, respectively. Dihydroartemisinin showed a strong therapeutic effect against falciparum malaria with a low toxicity.

• Journal of the Korean Chemical Society
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• v.55 no.1
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• pp.57-62
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• 2011

Sometimes inhabitants in remote areas have inadequate or no access to modern medicines or medical services. They can get benefit in term of the treatment against malaria by cultivating selected breeding of A. annua and making teas or decoctions from the plant materials following the proper way of tea preparation. In order to have the maximum extraction efficiency for artemisinin, different ways of tea preparations of A. annua were investigated by applying the developed DPP method and described in this article. Tea was prepared by three different ways (cooking, without cooking with/without shaking and microwave oven) with different times. From the results, it has been found that higher concentration of artemisinin (84.7%) can be attained by following the approach for tea preparation without cooking with shaking for 15 minutes (R.S.D. 2.34%). The concentration of artemisinin decreases with cooking more than 1.5 min in microwave oven. The utmost extraction (88.9% of artemisinin) is possible to extract by shaking with boiled 5% ethanol in distilled water (R.S.D. 2.28%).

• Journal of the Korean Data and Information Science Society
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• v.28 no.4
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• pp.831-841
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• 2017

The irrational number ${\pi}$ is defined as the ratio of circumference of a circle to its radius and always becomes constant. This article does Monte Carlo approximation of its value using the famous Buffon's needle experiment and shows that its convergence is not always proportional to the sample size. We also do Monte Carlo simulations to see the convergence of the computed ${\pi}$ values from the random walk series with independent normal increment. Finally we apply the theoretical derivation to various financial time series data such as KOSPI, stock prices of Korean big firms, global stock indices and major foreign exchange rates. The historical data shows that log transformed data random walk process but most of their first lagged data don't follow a normal distribution. More importantly the computed value from the ratio of the regression coefficient ${\pi}$ tend to converge a constant, unfortunately not ${\pi}$. Using this result we could doubt on the efficient market hypothesis, and relate the degree of the hypothesis with the amount of deviation of the estimated ${\pi}$ values.