• Applied Biological Chemistry
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• v.47 no.2
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• pp.164-169
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• 2004

In the course of our screening for biocontrol agent (BCA) against Streptomyces scabiei and S. turgidiscabies causing potato scab using 5,000 actinomtcete isolates, 9 antagonistic strains were selected as BCA candidates through in vitro and in vivo assay. An antagonistic strain, A020645 was highly resistant to some pesticides and antibiotics such as dazomet and mancozeb and showed high control value in vivo. Two bioactive compounds (compound A, B) were purified by anion exchange chromatography, solid phase (ODS) extraction, TLC and reverse phase HPLC. Their chemical structures are now thought to be nucleoside derivative as determined by $^1H-NMR$ data analysis. Their full chemical structures would be elucidated through $^{13}C-NMR$, HMQC and HMBC analyses. Further studies will be focused on fitness in soil and formulation of the BCA candidates.

• The Transactions of the Korea Information Processing Society
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• v.4 no.11
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• pp.2786-2800
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• 1997

In this paper, we investigate how well the channel memory (statistical dependence in the occurrence of transmission errors) can be used in the evaluation of widely used error control schemes. For this we assume a special case named as the simplest Markovian block-error pattern with two states, in which each block is classified into two classes of whether the block transmission is in error or not. We apply the derived pattern to the performance evaluation of the practical link-level procedures, LAPB/D/M with multi-reject options, and investigate both throughput and user-perceived response time behaviors on the discrete-time domain to determine how much the performance of error recovery action is improved under burst error condition. Through numerical examples, we show that the simplest Markovian block-error pattern tends to be superior in throughput and delay characteristics to the random error case. Also, instead of mean alone, we propose a new measure of the response time specified as mean plus two standard deviations 50 as to consider user-perceived worst cases, and show that it results in much greater sensitivity to parameter variations than does mean alone.

• The Korean Journal of Physiology and Pharmacology
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• v.23 no.1
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• pp.47-54
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• 2019

Estrogen withdrawal in post-menopausal women leads to overactivation of osteoclasts, which contributes to the development of osteoporosis. Inflammatory cytokines are known as one of mechanisms of osteoclast activation after estrogen deficiency. SPA0355 is a thiourea derivative that has been investigated for its antioxidant and anti-inflammatory activities. However, its efficacy in bone resorption has not been previously investigated. The aim of this study was to investigate the impact of SPA0355 on the development of osteoporosis and to explore its mode of action. In vitro experiments showed that SPA0355 inhibited receptor activator of $NF-{\kappa}B$ ligand (RANKL)-induced osteoclastogenesis in primary bone marrow-derived macrophages. This effect appears to be independent of estrogen receptor activation as ICI 180,782 failed to abrogate its effects on osteoclasts. Further signaling studies revealed that SPA0355 suppressed activation of the MAPKs, Akt, and $NF-{\kappa}B$ pathways. SPA0355 also increased osteoblastic differentiation, as evidenced by its effects on alkaline phosphatase activity and mineralization nodule formation. Intraperitoneal administration of SPA0355 to ovariectomized mice prevented bone loss, as verified by three-dimensional images and bone morphometric parameters derived from ${\mu}CT$ analysis. Noticeably, SPA0355 did not show hepatotoxicity and nephrotoxicity and also had little effect on hematological parameters. Taken together, the results indicate that SPA0355 may protect against bone loss in ovariectomized mice by stimulation of osteoblast differentiation and by inhibition of osteoclast resorption. Therefore, SPA0355 is a safe and potential candidate for management of postmenopausal osteoporosis.

• Journal of Biomedical and Translational Research
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• v.19 no.4
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• pp.130-139
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• 2018

This study aimed to analyze a high-performance liquid chromatography (HPLC) separation using a pentafluorophenyl column of parent drug hydroxychloroquine (HCQ) and its active metabolite, desethylhydroxchloroquine (DHCQ) applying to determine bioequivalence of two different formulations administered to patients. A rapid, simple, sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for bioanalysis of HCQ and its metabolite DHCQ in human whole blood using deuterium derivative $hydroxychloroquine-D_4$ as an internal standard (IS). A triple-quadrupole mass spectrometer was operated using electrospray ionization in multiple reaction monitoring (MRM) mode. Sample preparation involves a two-step precipitation of protein techniques. The removed protein blood samples were chromatographed on a pentafluorophenyl (PFP) column ($50mm{\times}4.6mm$, $2.6{\mu}m$) with a mobile phase (ammonium formate solution containing dilute formic acid) in an isocratic mode at a flow rate of 0.45 mL/min. The standard curves were found to be linear in the range of 2 - 500 ng/mL for HCQ; 2 - 2,000 ng/mL for DHCQ in spite of lacking a highly sensitive MS spectrometry system. Results of intra- and inter-day precision and accuracy were within acceptable limits. A run time of 2.2 min for HCQ and 2.03 min for DHCQ in blood sample facilitated the analysis of more than 300 human whole blood samples per day. Taken together, we concluded that the assay developed herein represents a highly qualified technology for the quantification of HCQ in human whole blood for a parallel design bioequivalence study in a healthy male.

• Journal of Animal Science and Technology
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• v.61 no.3
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• pp.138-146
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• 2019

Vitamin $B_3$ (niacin) is essential for all living cells and plays a central role in energy metabolism and oxidative phosphorylation. Vitamin $B_3$, a water-soluble vitamin, is present in the form of nicotinic acid and nicotinamide, a monocarboxylic acid derivative of pyridine. While nicotinic acid is commonly effective in lowering cholesterol levels, unlike nicotinic acid, nicotinamide is ineffective on lipids. Presence rates of nicotinic acid and nicotinamide, which are the available forms of vitamin $B_3$, are different for each food. However, the studies in the literature are generally based on the analysis of total amount of vitamin $B_3$ in foods and the studies determining the profile of vitamin $B_3$ in foods are limited. The aim of the study was to determine the vitamin $B_3$ profiles of 10 kinds of animal based food and 10 different plant based food samples. In this study, 10 kinds of animal based food samples consisting of veal (veal steak fillet), chicken (breast), turkey meat (thigh), goat meat (leg, belly), lamb (leg, back, arm), mutton (belly), bovine meat (loin) and 10 different plant based food samples namely; barley, rye, wheat (bread), wheat (durum), oat, rice, dried pea, green lentil, red lentil and chickpea were studied by high performance liquid chromatography using post-column derivatization system. The presence rates of nicotinic acid and nicotinamide were determined in the meat samples as 30% and 70% and as 87% and 13% in the cereal and legume samples, respectively. Nicotinic acid levels were found in low amounts in the meat samples. The amounts of nicotinic acid in the cereal and legume samples were significantly higher than the meat samples. Consequently, the plant based foods such as cereals and legumes, with a ratio of 87% nicotinic acid presence, standout as the best source of nicotinic acid and encouraging regular intake of those cereals and legumes containing rich nicotinic acid would remove nicotinic acid deficiency in human.

• Advances in nano research
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• v.10 no.4
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• pp.359-371
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• 2021

A tumor immune interaction is a main topic of interest in the last couple of decades because majority of human population suffered by tumor, formed by the abnormal growth of cells and is continuously interacted with the immune system. Because of its wide range of applications, many researchers have modeled this tumor immune interaction in the form of ordinary, delay and fractional order differential equations as the majority of biological models have a long range temporal memory. So in the present work, tumor immune interaction in fractional form provides an excellent tool for the description of memory and hereditary properties of inter and intra cells. So the interaction between effector-cells, tumor cells and interleukin-2 (IL-2) are modeled by using the definition of Caputo fractional order derivative that provides the system with long-time memory and gives extra degree of freedom. Moreover, in order to achieve more efficient computational results of fractional-order system, a discretization process is performed to obtain its discrete counterpart. Furthermore, existence and local stability of fixed points are investigated for discrete model. Moreover, it is proved that two types of bifurcations such as Neimark-Sacker and flip bifurcations are studied. Finally, numerical examples are presented to support our analytical results.

• The korean journal of orthodontics
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• v.52 no.4
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• pp.268-277
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• 2022

Objective: Poor experience with Invisalign treatment affects patient compliance and, thus, treatment outcome. Knowing the potential discomfort level in advance can help orthodontists better prepare the patient to overcome the difficult stage. This study aimed to construct artificial neural networks (ANNs) to predict patient experience in the early stages of Invisalign treatment. Methods: In total, 196 patients were enrolled. Data collection included questionnaires on pain, anxiety, and quality of life (QoL). A four-layer fully connected multilayer perception with three backpropagations was constructed to predict patient experience of the treatment. The input data comprised 17 clinical features. The partial derivative method was used to calculate the relative contributions of each input in the ANNs. Results: The predictive success rates for pain, anxiety, and QoL were 87.7%, 93.4%, and 92.4%, respectively. ANNs for predicting pain, anxiety, and QoL yielded areas under the curve of 0.963, 0.992, and 0.982, respectively. The number of teeth with lingual attachments was the most important factor affecting the outcome of negative experience, followed by the number of lingual buttons and upper incisors with attachments. Conclusions: The constructed ANNs in this preliminary study show good accuracy in predicting patient experience (i.e., pain, anxiety, and QoL) of Invisalign treatment. Artificial intelligence system developed for predicting patient comfort has potential for clinical application to enhance patient compliance.

• Journal of Microbiology and Biotechnology
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• v.31 no.6
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• pp.855-866
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• 2021

The effects of various carbon sources on mycelial growth and polysaccharide synthesis of the medicinal fungus Inonotus obliquus in liquid fermentation were investigated. After 12-d fermentation, mycelial biomass, polysaccharide yield, and polysaccharide content were significantly higher in Glc+Lac group (glucose and lactose used as combined carbon source) than in other groups. Crude polysaccharides (CIOPs) and the derivative neutral polysaccharides (NIOPs) were obtained from mycelia fermented using Glc, fructose (Fru), Lac, or Glc+Lac as carbon source. Molecular weights of four NIOPs (termed as NIOPG, NIOPF, NIOPL, and NIOPGL) were respectively 780.90, 1105.00, 25.32, and 10.28 kDa. Monosaccharide composition analyses revealed that NIOPs were composed of Glc, Man, and Gal at different molar ratios. The NIOPs were classified as α-type heteropolysaccharides with 1→2, 1→3, 1→4, 1→6 linkages in differing proportions. In in vitro cell proliferation assays, viability of RAW264.7 macrophages was more strongly enhanced by NIOPL or NIOPGL than by NIOPG or NIOPF, and proliferation of HeLa or S180 tumor cells was more strongly inhibited by NIOPG or NIOPGL than by NIOPF or NIOPL, indicating that immune-enhancing and anti-tumor activities of NIOPs were substantially affected by carbon source. qRT-PCR analysis revealed that expression levels of phosphoglucose isomerase (PGI) and UDP-Glc 4-epimerase (UGE), two key genes involved in polysaccharide synthesis, varied depending on carbon source. Our findings, taken together, clearly demonstrate that carbon source plays an essential role in determining structure and activities of I. obliquus polysaccharides by regulating expression of key genes in polysaccharide biosynthetic pathway.

• Archives of Plastic Surgery
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• v.49 no.3
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• pp.304-309
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• 2022

Background Laminin 5, which is found in the basement membrane of dermal-epidermal junction (DEJ), is a major adhesive component and associated with proliferating and migrating keratinocytes. In this study, we hypothesized that the topical application of the skin care products containing the novel peptides might restore the DEJ structure by deriving deposition of laminin 5 and promoting the keratinocyte migration. Here, we evaluated the restoration of DEJ by measuring the skin thickness. Methods Single-center retrospective analysis was performed on a total of 13 patients who underwent skin care using Baume L.C.E. (France, Laboratories d' Anjou) between January and March 2021. All patients applied the skin care agent for 2 weeks only on their left hand dorsum. Before the initiation of the application and after 2 weeks, both their hands were evaluated on photography and ultrasound. And the patients were asked to rate their satisfaction with the questionnaire after 2 weeks. Results There was no obvious improvement in photographic assessment and questionnaire. The post-pre difference of skin thickness in ultrasound images was, in left hand, 0.1 ± 0.37 in distal point and 0.1 ± 0.35 in proximal point; and, in right hand, 0 ± 0.17 in distal point and 0 ± 0.15 in proximal point, respectively. The pre-post difference was statistically significant in proximal point (p = 0.035). Conclusion Topical application of novel peptide derivative comprising laminin 5 demonstrated cutaneous changes including skin thickness, as assessed by ultrasound. Further studies using other modalities including dermal density measurement, three-dimensional photography, optical coherence tomography, or skin biopsy would be helpful to determine the skin-improving effects.

• Geomechanics and Engineering
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• v.28 no.1
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• pp.49-64
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• 2022

In this work, the bending and dynamic behaviors of advanced composite plates resting on variable visco-Pasternak foundations are studied using a simple shear deformation integral plate model. The research is carried out with a view to a three-parameter foundation including the influences of the variable Winkler coefficient, the constant Pasternak coefficient and the damping coefficient of the elastic medium. The present theory uses a displacement field with integral terms instead of derivative terms by including also the shear deformation effect without introducing the shear correction factors. The equations of motion for advanced composite plates are obtained using the Hamilton principle. Analytical solutions for the bending and dynamic analysis are deduced for simply supported plates resting on variable visco-Pasternak foundations. Some numerical results are presented to demonstrate the impact of material index, elastic foundation type, and damping coefficient of the foundation, on the bending and dynamic responses of advanced composite plates.