• International Journal of Oral Biology
• /
• v.34 no.4
• /
• pp.191-197
• /
• 2009

Somatostatin (SST) is a known neuromodulator of the central nervous system. The substantia gelatinosa (SG) of the trigeminal subnucleus caudalis (Vc) receives many thinmyelinated $A{\delta}$-fiber and unmyelinated C primary afferent fibers and is involved in nociceptive processing. Many studies have demonstrated that SST plays a pivotal role in pain modulation in the spinal cord. However, little is yet known about the direct effects of SST on the SG neurons of the Vc in adult mice. In our present study, we investigated the direct membrane effects of SST and a type 2 SST receptor agonist, seglitide (SEG), on the SG neurons of the Vc using a gramicidin-perforated current clamp in adult mice. The majority (53%, n = 27/51) of the adult SG neurons were hyperpolarized by SST (300 nM) but no differences were found in the hyperpolarization response rate between males and females. When SST was applied successively, the second response was smaller ($76{\pm}9.5%$, n=19), suggesting that SST receptors are desensitized by repeated application. SST-induced hyperpolarization was also maintained under conditions where presynaptic events were blocked ($75{\pm}1.0%$, n=5), suggesting that this neuromodulator exerts direct effects upon postsynaptic SG neurons. SEG was further found to induce membrane hyperpolarization of the SG neurons of the Vc. These results collectively demonstrate that SST inhibits the SG neuronal activities of the Vc in adult mice with no gender bias, and that these effects are mediated via a type 2 SST receptor, suggesting that this is a potential target for orofacial pain modulation.

• Journal of Environmental Science International
• /
• v.10 no.3
• /
• pp.187-194
• /
• 2001

For the purpose of predicting air pollutants concentration in Pusan coastal urban, we used an Eulerian model of flow and dispersion/chemistry/deposition process considering SST effects which estimate through POM. The results of air quality model including emission from various sources show that the seasonal variation pattern of respective pollutants was affected by the seasonal SST fields and local circulation. Horizontal deviation of diurnal SST was 2.5~4K, especially large gradients in coastal region. Through numerical simulation of wind fields we predicted that local circulation prevailed during daytime in summer and nighttime in winter. So high concentration distribution showed toward inland in spring and summer seasons, while high concentration distribution showed at inland near coast in autumn and winter.

• The Journal of Asian Finance, Economics and Business
• /
• v.7 no.9
• /
• pp.489-497
• /
• 2020

The introduction of self-service technologies (SSTs) in retail stores aims to provide customers with a more satisfying shopping experience. Many retailers are increasingly turning toward the adoption of self-service technologies in providing services directly to customers. Given that previous SST research has focused mainly on the impact of the introduction of SST on customer responses, the present study explored the impact of the presence of employees in the relationship between SST and customer responses. Based on the two ground theories, motivation-based theories of behavior and social impact theory, this study tested the relationships between shopping motivations, SST use intention, and retailer attitude. Moderating effects of the presence of employees on the three relationships were also tested. Data were collected using an online survey and analyzed through structural equations modeling. Test results showed that both hedonic and utilitarian shopping motivations effect on SST use intentions, and SST use intentions effect on retailer attitude, subsequently. Although the presence of employee did not moderate the relationship between shopping motivations and SST use intentions, the employee presence moderated the relationship between SST use intentions and retailer attitude. The impact of SST use intentions on retailer attitude was higher in the high presence of employee group than in the low group.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.18 no.1
• /
• pp.137-147
• /
• 2004

In order to evaluate the antitumor activity and immunomodulatory effects of Seoleosojong-tang(SST), studies were done. We measured the cytotoxic activity for various kinds of cancer cells, inhibitory effect on activity of DNA topoisomerase I, cell adhesion to complex extracellular matrix, survival time in ICR bearing S-180, pulmonary colonization and histological changes of lung in C57BL/6 injected i.v. with B16-F10, CAM assay, expression of CD4/sup +/, CD8/sup +/, B220/sup +/, cytokine gene in spleen cell. The results were obtained as follows: 1. In cytotoxicity against A549, HT1080, 816-F10, NCL-H661 was showed cytotoxicity as compared with control. 2. The inhibitory effect on adhesion of A549, 816-F10 to complex extracellular matrix was over 40% at 100 ㎍/㎖ of SST. 3. In DNA topoisomerase I assay, SST has inhibitory effect. 4. The T/C% was 120.8 in SST treated group in S-180 bearing ICR mice. 5. In pulmonary colonization assay, a number of colonies were decreased significantly and histological changes were showed that infiltration area of cancer cells were inhibited effectively in SST treated group. 6. In CAM Assay, SST has antiangiogenic effect. 7. On the expression of positive cell to CD4/sup +/, CD8/sup +/ and 8220/sup +/ in spleen cells, CD4/sup +/ cells were increased significantly in SST treated group. 8. Effect of SST on IL-1β gene expression in splenic cell was significantly increased as function of whole concentration. 9. The gene expression of IL-4, IL-6, IL-10, IL-12, IFN-γ, TNF-α were increased in SST treated group. From above results SST could be usefully applied for antitumor activity and immunomodulatory effects, but further research of SST should be required.

• Atmosphere
• /
• v.23 no.2
• /
• pp.161-169
• /
• 2013

We examine the effects of the sea surface temperature (SST) distribution on heavy snowfall over the Yellow Sea using high-resolution SST products and WRF (Weather Research and Forecasting) model simulations in 30 December 2010. First, we evaluate the model by comparing the simulated and observed fresh snowfall over the Korean peninsula (Ho-Nam province). The comparison shows that the model reproduces the distributions and magnitudes of the observed snowfall. We then conduct sensitivity model simulations where SST perturbations by ${\pm}1.1^{\circ}C$ relative to baseline SST values (averaged SST for $5{\sim}15^{\circ}C$) are uniformly specified over the region of interest. Results show that ${\pm}1.1^{\circ}C$ SST perturbation simulations result in changes of air temperature by $+0.37/-0.38^{\circ}C$, and by ${\pm}0.31^{\circ}C$ hPa for sea level pressure, respectively, relative to the baseline simulation. Atmospheric responses to SST perturbations are found to be relatively linear. The changes in SST appear to perturb precipitation variability accounting for 10% of snow and graupel, and 18% of snowfall over the Yellow Sea and Ho- Nam province, respectively. We find that anomalies of air temperature, pressure, and hydrometeors due to SST perturbation propagate to the upper part of cloud top up to 500 hPa and show symmetric responses with respect to SST changes.

• The Korean Journal of Franchise Management
• /
• v.12 no.1
• /
• pp.7-19
• /
• 2021

Purpose: According to the growth of technology in the service industry, the interaction service between customer and employee has recently been transformed into between customer and technology by Self Service Technology (SST) requiring direct interaction with customers. In this context, self service technology such as unmanned ordering system installed at the store is actively introduced at the work place to reduce labor costs by food and retail company and the research for self-service technology which is rapidly replacing existing face-to-face service is needed. As the growth speed of SST is rapid, many researchers have studied the characteristics of SST, in every sector of business worldwide. Among the characteristics, attributes, Self Service Technology Quality (SSTQUAL) to evaluate SST is important because it may cause the customer's behavior. Thus, this research focuses on the effects of SSTQUAL on SST Satisfaction and SST continuance usage intention. This research suggests the guidelines for how Restaurant Company should prepare SST and build their customer satisfaction and continuance usage that increase the sales. Research design, data and methodology: This study tests the structural relationship between SSTQUAL of unmanned ordering system, SST satisfaction and SST continuance usage. SSTQUAL divided into four sub-dimensions and two categories, cognitive service attributes (Convenience, Functionality) and affective service attributes (Enjoyment, Assurance). In order to achieve the purposes of this research, research model and hypotheses were developed based on previous researches. All constructs were measured with multiple items developed and tested in the previous studies. The data were collected from 524 customers experiencing SST and were analyzed through SPSS 25.0 and SmartPLS 3.0 statistical package program. Results: The findings of this research are as follows. First, all SSTQUAL have significant positive impacts on SST satisfaction. Second, SST satisfaction has significant positive impact on SST continuance intention. Third, cognitive service attributes and affective service attributes had wealth of explanation of service attribute more than a single dimension. Conclusions: The implications of this study are as follows. Overall, Restaurant Company should manage SSTQUAL consisting of not only cognitive service attributes (Convenience, Functionality) but also affective service attributes (Enjoyment, Assurance) to satisfy customers basically regardless of the type of restaurant.

• The Korean Journal of Physiology and Pharmacology
• /
• v.7 no.2
• /
• pp.79-84
• /
• 2003

We have previously reported that expression of the somatostatin receptor subtypes, sst1-5, is differentially regulated by growth hormone (GH)-releasing hormone (GHRH) and forskolin (FSK), in vitro. GHRH binds to membrane receptors selectively located on pituitary somatotropes, activates adenylyl cyclase (AC) and increases sst1 and sst2 and decreases sst5 mRNA levels, without significantly altering the expression of sst3 and sst4. In contrast FSK directly activates AC in all pituitary cell types and increases sst1 and sst2 mRNA levels and decreases sst3, sst4 and sst5 expression. Two explanations could account for these differential effects: 1) GHRH inhibits sst3 and sst4 expression in somatotropes, but this inhibitory effect is masked by expression of these receptors in unresponsive pituitary cell types, and 2) FSK inhibits sst3 and sst4 expression levels in pituitary cell types other than somatotropes. To differentiate between these two possibilities, somatotropes were sequentially labeled with monkey anti-rat GH antiserum, biotinylated goat anti-human IgG, and streptavidin-PE and subsequently purified by fluorescent-activated cell sorting (FACS). The resultant cell population consisted of 95% somatotropes, as determined by GH immunohistochemistry using a primary GH antiserum different from that used for FACS sorting. Purified somatotropes were cultured for 3 days and treated for 4 h with vehicle, GHRH (10 nM) or FSK ($10{\mu}M$). Total RNA was isolated by column extraction and specific receptor mRNA levels were determined by semi-quantitative multiplex RT-PCR. Under basal conditions, the relative expression levels of the various somatostatin receptor subtypes were sst2＞sst5＞sst3=sst1＞ sst4. GHRH treatment increased sst1 and sst2 mRNA levels and decreased sst3, sst4 and sst5 mRNA levels in purified somatotropes, comparable to the effects of FSK on purified somatotropes and mixed pituitary cell cultures. Taken together, these results demonstrate that GHRH acutely modulates the expression of all somatostatin receptor subtypes within GH-producing cells and its actions are likely mediated by activation of AC.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.18 no.5
• /
• pp.1382-1386
• /
• 2004

This study was performed for the investigation of vasodilatory efficacy and its underlying mechanisms of Samhwangsasim-tang(SST), herbal remedy. SST relaxed vascular strips precontracted with phenylephrine or KCI(51 mM), but the magnitude of relaxation was greater in phenylephrine(PE) induced contraction. The relaxation effects of SST was endothelium-independent. L-NAME, iNOS inhibitor, and methyl en blue(MB), cGMP inhibitor, did not attenuate the relaxation responses of SST. In the absence of extracellular Ca2+, pre-incubation of the aortic rings with SST significantly reduced the contraction by PE, suggesting that the relaxant action of the SST includes inhibition of Ca/sup 2+/ influx and release of Ca/sup 2+/ from intracellular stores (SR). In addition, the cell death was induced by SST in human aortic smooth muscle cells but not that of human umbilical vein endothelial cells. We conclude that in rat thoracic aorta, SST may induce in part vasodilation through inhibition of Ca/sup 2+/ influx and release of Ca/sup 2+/ from intracellular stores.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.21 no.3
• /
• pp.688-699
• /
• 2007

This experiment was designed to investigate the effect of the SST hot water extract & ultra-fine Powder on Alzheimer's Disease Model Induced by ${\beta}$A. The effects of the SST hot water extract on expression of IL-1${\beta}$, IL-6, TNF-${\alpha}$, NOS-II, COX-2 mRNA and production of IL-l${\beta}$, IL-6, TNF-${\alpha}$, NO in BV2 microglial cell line treated by lipopolysacchaide(LPS). The effects of the SST hot water extract & ultra-fine powder on (1) the behavior (2) expression of IL-1${\beta}$, TNF-${\alpha}$, MDA, (3) Glucose, AChE in serum (4) the infarction area of the hippocampus, and brain tissue injury in Alzheimer's diseased mice induced with ${\beta}$A were investigated. The SST hot water extract suppressed the expression of IL-1${\beta}$, IL-6 and TNF-a mRNA ${\alpha}$in BV2 microglia cell line treated with LPS. The SST hot water extract suppressed the production of IL-1${\beta}$, IL-6, TNF-${\alpha}$, NO in BV2 microglial cell line treated with LPS. The SST hot water extract & ultra-fine powder a significant inhibitory effect on the memory deficit was shown for the mice with Alzheimer's disease induced by ${\beta}$A in the Morris water maze experiment, which measured stop-through latency. The SST ultra-fine powder suppressed the expression of TNF-a protein significantly in the microglial cell of mice with Alzheimer's disease induced by ${\beta}$A. The SST hot water extract & ultra-fine powder reduced the MDA and suppressed the over-expression of CD68, CD11b in the mice with Alzheimer's disease induced by ${\beta}$A. The SST hot water extract & ultra-fine powder decreased AChE significantly in the serum of the mice with Alzheimer's disease induced by ${\beta}$A. The SST hot water extract & ultra-fine powder reduced infarction area of hippocampus, and controlled the injury of brain tissue in the mice with Alzheimer's disease induced by ${\beta}$A. The SST hot water extract & ultra-fine powder reduced the tau protein, GFAP, and presenilin1, 2 of hippocampus in the mice with Alzheimer's disease induced by ${\beta}$A. These results suggest that the SST hot water extract & ultra-fine powder may be effective for the prevention and treatment of A1zheimer's disease. Investigation into the clinical use of the SST hot water extract & ultra-fine powder for Alzheimer's disease is suggested for future research.

• Herbal Formula Science
• /
• v.8 no.1
• /
• pp.241-255
• /
• 2000

Sihosamultang(SST) has been used for the treatment of puerperal fever, liver disease in traditional medicine. The present study was carried out to evaluate the antioxidant effects of SST extract in vitro. The inhibitory effect of SST extract on lipid peroxidant was examined in the linoleic acid autoxidation system. In this test, SST extract significantly inhibited the time course of the lipid peroxidation. And SST extract showed about 73% scavenging effect on DPPH radical. And this extract inhibited not only the lipid peroxide formation induced by hydroxyl radical derived from $ H_{2}O_{2}-Fe^{2+}$ in the rat liver homogenate, but also the superoxide generation from xanthine-xanthine oxidase system in a dose-dependent manner. In addition, SST extract protected the hepatic cell death induced by tert-butyl hydroperoxide. These data indicated that SST might play a protective role against oxidative injury by free radicals.