• The Journal of the Korean dental association
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• v.53 no.10
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• pp.743-750
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• 2015

Objectives: This study compared the mechanical efficacy of sonic activated and passive ultrasonic irrigation for removing intracanal medicament from a simulated root canal under controlled conditions. Materials and Methods: Thirty simulated root canal in resin blocks were randomly divided into 3-groups. The canals were enlarged using ProTaper files and K3XF (#30/0.06). After cleaning and drying, canals were filled with Calcipex. Overfilled materials were wiped out and measured their weight to the unit of 1/10mg. After one week storage in 100% humidity $37^{\circ}C$ temperature, canals were irrigated using 20mL of saline with one of following methods according to the designated groups (n = 10). For group-NI, 30-gauge nickel-titanium irrigation needle was used. During irrigation with every 5mL, needle was moved in-and-out with 4-mm amplitudes. EndoActivator and ultrasonic tip were used for group-EA and group-UT respectively for 20 seconds after every 5mL irrigation using needle. Then the weight was measured again to calculate the weight of residual remnants. The data were analyzed by one-way ANOVA and Duncan's post-hoc test at a significance level of 95%. Results: The weight of the residual medicaments were $3.62{\pm}0.81mg$, $2.84{\pm}0.28mg$, and $2.73{\pm}0.90mg$ for group-NI, -EA, and -UT, respectively. Group-EA and group-UT had no significant differences to remove intracanal medicament and left significantly less amount of paste than group-NI (p < 0.05). Conclusions: Under the controlled conditions of this study, the sonic activation and PUI have similar mechanical efficacy for removing intracanal medicament.

• Science of Emotion and Sensibility
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• v.14 no.1
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• pp.93-100
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• 2011

Sonic branding is defined as creation and management of brand value by using sounds. Among various methods of sonic branding, sonic logo, i.e., brand’s acoustic identification element, is the most widely used form and usually combined with visual logo. Although sonic branding has become an increasingly important tool for marketers, little academic research has been done on this topic. The current study investigates neural responses to sonic branding using functional Magnetic Resonance Imaging (fMRI). Brain activity of 15 right-handed participants was monitored with 3T MRI machine, while they viewed sequentially presented pictures of brand logos (20 visual logos usually accompanied by sonic logos and 20 visual logos unaccompanied by sonic logos) without sound. Results showed that brain areas known to be associated with auditory imagery (including superior temporal gyrus, STG), showed greater activation for the visual logos usually accompanied by sonic logos compared to visual logos unaccompanied by sonic logos, although actual sound was not presented during scanning. The degree of familiarity participants have with the brand and its advertisements was correlated positively with signal strength in these areas.

• Molecules and Cells
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• v.26 no.4
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• pp.380-386
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• 2008

During embryonic and cancer development, the Hedgehog family of proteins, including Sonic Hedgehog, play an important role by relieving the inhibition of Smo by Ptc, thus activating the Smo signaling cascade. Recently, a purine compound, purmorphamine, has been reported to target the Hedgehog signaling pathway by interacting with Smo. Interestingly, both Sonic Hedgehog and purmorphamine were found to promote the osteogenic differentiation of mouse chondroprogenitor cells. However, there is insufficient information as to how the activation of this seemingly unrelated signaling pathway, either by Sonic Hedgehog or purmorphamine, contributes to osteogenesis. Using alkaline phosphatase assays, we screened 125 purmorphamine derivatives from the Korea Chemical Bank for effects on the differentiation of preosteoblast C2C12 cells. Here, we report that two purine derivatives modulate ALP activity as well as the expression of genes whose expression is known or suggested to be involved in osteogenesis.

• Journal of the Korean institute of surface engineering
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• v.27 no.2
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• pp.109-117
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• 1994

Effect of ultrasonic agitation on the contact properties was studied in Ni electroless plating and Pd activation. P-type Si bare wafers were used as substrate and DMAB was used as reducing agent due to its good electrical properties, solderability and compatibility to substrate. In activation, high density Pd nuclei of small size were formed during ultra-sonic agitation compared to that of no stirring. In electroless plating, the plating rate was enhanced by 30∼90% by using ultrasonic agitation. In elecrtoless plating, inhibitor is the most effective additives in ultrasonic agitation. In this experi-ment, thiourea was used as inhibitor. The less the amount of the inhibitor, the more ultrasonic agitation efficiency. It is confirmed by SEM that Ni-B films formed by ultrasonic were coarser, less porous, and denser than those of no stirring. In ultrasonic agitation, boron content of the films was more than those of no stirring. In this case, the more DMAB concentration, the higher the temperature, the less pH, the more boron content. Resistivity of the films formed by ultrasonic agitation was higher than that of no strirring. As the content of boron was increased, the resistivity of the films was increased exponentially.

• Restorative Dentistry and Endodontics
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• v.46 no.1
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• pp.10.1-10.16
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• 2021

Root canal debridement, which includes the removal of infected tissues and microbial biofilms, is considered the corner stone of root canal treatment. Chemical adjuncts play a multitude of functions in this regard, as tissue solvents, antimicrobial agents and for removing the smear layer. These adjuncts (irrigants) are usually delivered using a syringe and needle. With increasing knowledge of the complexity of root canal anatomy and tenacity of microbial biofilms, the need for strategies that potentiate the action of these irrigants within the root canal system cannot be overemphasized. Several such activated irrigation strategies exist. The aim of this review is to comprehensively discuss the different irrigant activation methods from the context of clinical studies.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.2
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• pp.437-442
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• 2015

Aim: To establish a pancreatic cancer stem cell model using human pancreatic cancer cells in nude mice to provide a platform for pancreatic cancer stem cell research. Materials and Methods: To establish pancreatic cancer xenografts using human pancreatic cancer cell line SW1990, nude mice were randomly divided into control and gemcitabine groups. When the tumor grew to a volume of $125mm^3$, they treated with gemcitabine at a dose of 50mg/kg by intraperitoneal injection of 0.2ml in the gemcitabine group, while the mice in control group were treated with the same volume of normal saline. Gemcitabine was given 2 times a week for 3 times. When the model was established, the proliferation of pancreatic cancer stem cells was observed by clone formation assay, and the protein and/or mRNA expression of pancreatic stem cell surface markers including CD24, CD44, CD133, ALDH, transcription factors containing Oct-4, Sox-2, Nanog and Gli, the key nuclear transcription factor in Sonic Hedgehog signaling pathway was detected by Western blot and/or RT-PCR to verify the reliability of this model. Results: This model is feasible and safe. During the establishment, no mice died and the weight of nude mice maintained above 16.5g. The clone forming ability in gemcitabine group was stronger than that of the control group (p<0.01). In gemcitabine group, the protein expression of pancreatic cancer stem cell surface markers including CD44, and ALDH was up-regulated, the protein and mRNA expression of nuclear transcription factor including Oct-4, Sox-2 and Nanog was also significantly increased (P<0.01). In addition, the protein expression of key nuclear transcription factor in Sonic Hedgehog signaling pathway, Gli-1, was significantly enhanced (p<0.01). Conclusions: The pancreatic cancer stem cell model was successfully established using human pancreatic cancer cell line SW1990 in nude mice. Gemcitabine could enrich pancreatic cancer stem cells, simultaneously accompanied by the activation of Sonic Hedgehog signaling pathway.

• Development and Reproduction
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• v.25 no.4
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• pp.279-291
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• 2021

Hair loss is one of the most common chronic diseases, with a detrimental effect on a patient's psychosocial life. Hair loss results from damage to the hair follicle (HF) and/or hair regeneration cycle. Various damaging factors, such as hereditary, inflammation, and aging, impair hair regeneration by inhibiting the activation of hair follicle stem cells (HFSCs) and dermal papilla cells (DPCs). Formyl peptide receptor 2 (FPR2) regulates the inflammatory response and the activity of various types of stem cells, and has recently been reported to have a protective effect on hair loss. Given that stem cell activity is the driving force for hair regeneration, we hypothesized that FPR2 influences hair regeneration by mediating HFSC activity. To prove this hypothesis, we investigated the role of FPR2 in hair regeneration using Fpr2 knockout (KO) mice. Fpr2 KO mice were found to have excessive hair loss and abnormal HF structures and skin layer construction compared to wild-type (WT) mice. The levels of Sonic hedgehog (Shh) and β-catenin, which promote HF regeneration, were significantly decreased, and the expression of bone morphogenetic protein (Bmp)2/4, an inhibitor of the anagen phase, was significantly increased in Fpr2 KO mice compared to WT mice. The proliferation of HFSCs and DPCs was significantly lower in Fpr2 KO mice than in WT mice. These findings demonstrate that FPR2 impacts signaling molecules that regulate HF regeneration, and is involved in the proliferation of HFSCs and DPCs, exerting a protective effect on hair loss.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.1
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• pp.73-79
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• 2018

The primary cilium protrudes from the cell body like a bio-antenna that has many receptors, channels and signaling molecules to sense and response to external stimuli. The external environment such as ultraviolet irradiation, temperature, humidity, gravity and shear stress always influences skin. Skin responds to external stimuli and differentiates by making melanin, collagen and horny layer. Ciliogenesis participates in developmental processes of skin, such as keratinocyte differentiation and hair formation. And it was reported that skin pigmentation was inhibited when ciliogenesis was induced by sonic hedgehog-smoothened-GLI2 signaling. When skin is exposed to ultraviolet irradiation, alpha-melanocyte stimulating hormones (${\alpha}$-MSH) increase melanin synthesis through activation of the cAMP pathway in melanocytes. We observed that ${\alpha}$-MSH and cAMP production inducers inhibited ciliogenesis of melanocytes. Therefore, we thought that regulation of ciliogenesis is potential candidate target for the development of agents to treat undesirable hyperpigmentation of skin. As a result, we found out that an ethanol extract of Glycyrrhiza glabra (EGG) root and 3,4,5-trimethoxy cinnamate thymol ester (TCTE, Melasolv) significantly inhibit melanin synthesis of normal human melanocyte by inducing primary cilium formation. This study proposed new theory to regulate skin pigmentation and cosmetic components for skin whitening.

• Restorative Dentistry and Endodontics
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• v.48 no.3
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• pp.25.1-25.13
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• 2023

Objectives: The purpose of this study was to evaluate the influence of endodontic access cavities design on the removal of calcium hydroxide medication of the apical third of mandibular incisor root canal walls and dentinal tubules with different cleaning protocols: EDDY sonic activation, Er,Cr:YSGG laser-activated irrigation, or conventional irrigation with IrriFlex. Materials and Methods: Seventy-eight extracted human mandibular incisors were assigned to 6 experimental groups (n = 13) according to the endodontic access cavity and cleaning protocol for calcium hydroxide removal: traditional access cavity (TradAC)/EDDY; ultraconservative access cavity performed in the incisal edge (UltraAC.Inc)/EDDY; TradAC/Er,Cr:YSGG; UltraAC. Inc/Er,Cr:YSGG; TradAC/IrriFlex; or UltraAC.Inc/IrriFlex. Confocal laser scanning microscopy images were used to measure the non-penetration percentage, maximum residual calcium hydroxide penetration depth, and penetration area at 2 and 4 mm from the apex. Data were statistically analyzed using Shapiro-Wilk and WRS2 package for 2-way comparison of non-normally distributed parameters (depth of penetration, area of penetration, and percentage of non-penetration) according to cavity and cleaning protocol with the significance level set at 5%. Results: The effect of cavity and cleaning protocol interactions on penetration depth, penetration area and non-penetration percentage was not found statistically significant at 2 and 4 mm levels (p > 0.05). Conclusions: The present study demonstrated that TradAC or UltraAC.Inc preparations with different cleaning protocols in extracted mandibular incisors did not influence the remaining calcium hydroxide at 2 and 4 mm from the apex.