Salivary gland dysfunction is a common complication of diabetes. Decreased saliva production and changes in saliva composition may cause oral diseases. Reactive oxygen species (ROS) generation in the salivary glands results in the loss of acinar cells and decreased saliva secretion. Glucagon-like peptide 1 (GLP-1) is the incretin hormone that regulates blood glucose level and can suppress ROS production and inflammation through its antioxidant effects. Dipeptidyl peptidase-4 (DPP-4) is an enzyme that breaks down GLP-1. In this study, we evaluated the pathological role of DPP-4 and GLP-1 on salivary gland dysfunction in type 2 diabetic db/db mice. We observed reduced salivary secretion and histopathological alteration of salivary glands in the db/db mice. The increased DPP-4 and decreased GLP-1 levels in the salivary glands were also detected in the db/db mice. Furthermore, the db/db mice had increased apoptosis and oxidative injury in salivary glands. There was an accumulation of advanced glycation end products and mucus in the salivary glands of the db/db mice. In conclusion, these results showed the possible involvement of DPP-4 and GLP-1, leading to increased ROS-induced apoptosis in diabetes-related salivary gland dysfunction. DPP-4 and GLP-1 may be a pharmacological target for patients with diabetes-related salivary gland dysfunction.

Background: The Natural killer cell activity measurement test of the ELISA method developed by company A could have many economic benefits in terms of cost and time compared to the existing 'cytotoxicity test method'. A portable incubator capable of culturing the specimen while moving was developed as a way to save test time and secure the stability of the specimen when transferring the specimen to the entrusted institution. Objectives: This study investigated efficacy evaluation of NK cell activity measurement in a portable incubator. Design: Experimental research. Methods: 100 participants were selected to measure NK cell activity. The collected blood was placed in a general incubator and a portable incubator at the same time to start culturing, and the plasma was separated by centrifugation. The NK cell activity test was measured by enzyme immunometry. Results: In the verification of the culturing performance of the developed portable incuvator, no significance was found between the general incuvator and the portable incuvator, and the same performance was maintained in culture. Conclusion: Portable incubators have a great effect on shortening the test time and securing the stability of samples.

We introduce the Transformable Reflective Telescope (TRT) kit that applies an aluminum profile as a base plate for precise, stable, and lightweight optical system. It has been utilized for optical surface measurements, developing alignment and baffle systems, observing celestial objects, and various educational purposes through Research & Education projects. We upgraded the TRT kit using the aluminum profile and truss and isogrid structures for a high-end optical test device that can be used for prototyping of precision telescopes or satellite optical systems. Thanks to the substantial aluminum profile and lightweight design, mechanical deformation by self-weight is reduced to maximum 67.5 μm, which is an acceptable misalignment error compared to its tolerance limits. From the analysis results of non-linear vibration simulations, we have verified that the kit survives in harsh vibration environments. The primary mirror and secondary mirror modules are precisely aligned within 50 μm positioning error using the high accuracy surface finished aluminum profile and optomechanical parts. The cross laser module helps to align the secondary mirror to fine-tune the optical system. The TRT kit with the precision aluminum mirror guarantees high quality optical performance of 5.53 μm Full Width at Half Maximum (FWHM) at the field center.

Declined salivary gland function is commonly observed in patients with diabetes. Advanced glycation end products (AGEs) are believed to contribute to the pathogenesis of diabetes-induces hypofunction of the salivary glands. Polydatin (resveratrol-3-O-β-mono-D-glucoside) is a polyphenol that can be easily accessed from peanut, grape, and red wines. Although polydatin is known to have anti-glycation, anti-oxidation, and anti-inflammation effects, its effect in the salivary gland is not known. In the present study, we evaluated the AGEs burden in the salivary gland in streptozotocin (STZ)-induced diabetic rats and the protective effect of polydatin on diabetes-related salivary hypofunction. Polydatin (50 and 100 mg/kg/day) was orally administered in the STZ-induced diabetic rats for 4 weeks. The results showed that the salivary flow rate of the STZ-induced diabetic rats was reduced compared with that in the normoglycemic control rats. The circulating AGEs in serum and secreted AGEs in saliva increased in the STZ-induced diabetic rats. The reactive oxygen specises (ROS) were highly generated in the salivary gland in these diabetic rats. The salivary gland from the diabetic rats showed increased acinar cell apoptosis compared to normoglycemic control mice. However, polydatin suppressed all of these diabetes-related salivary changes. Overall, polydatin could provide a beneficial option for diabetes-related salivary hypofunction.

The study investigated the individual coaching effect on TOEIC learning among college students. The participants were the 145 college students in Incheon who had taken TOEIC reading comprehension classes for two semesters. Two series of simple TOEIC tests were executed to measure the students’ English proficiency on the first day of each semester. Individual coaching was conducted through counseling and learning guidance for 25 students with the lower scores (3~7 points out of 25 based on the first simple TOEIC test). Among them, eight students participated in the in-depth interview at the beginning of each semester. When comparing the simple TOEIC test results of the two groups, the difference between the averages of the two groups was clear only with regard to the first semester. The t-test showed no proven statistical differences in the second semester outcomes. The results of paired-sample t-test on the change in the simple TOEIC scores before and after individual coaching in the individual and class coaching mixed group was also statistically verified. Individual coaching in this study was to find an appropriate learning process for the students with low language fluency, and it took place for a relatively long time. The interaction between the students and the professor in individual coaching created a special rapport between them.

In this study, we theorize that the way consumers communicate on social media (“liking”2 vs. posting) leads to consequential preferences for luxury products. Specifically, for light users, who spend less than one hour on social media, “liking” (vs. posting) strengthens (vs. weakens) preference for social value-framed luxury products (i.e., creates a good impression to others) compared to functional value-framed products (i.e., superior quality). This contrasts with heavy users, who spend more than two hours on social media, where posting (vs. “liking”) strengthens (vs. weakens) preference for social value-framed luxury products compared to functional value-framed products. Thus, the relationship between social media interaction (“liking” vs. posting) and preference for luxury products is conditionally mediated by communication expectation with others. Both the direct effect and indirect effect are moderated by the time spent on social media and luxury value type.

When social media users post their opinion on social media, they might expect to receive a favorable evaluation from others (e.g., ‘like’ on Facebook and ‘heart’ on Instagram). On the contrary, when users read and evaluate other’s posts, they are less likely to care about others. What’s more, if users spend more time on social media, posting would make them more care about others. This research answers the question ‘Does social media interaction alter the way we perceive value and affect different choice? Three studies show 1) how social media interaction affects consumers’ luxury value perception and the mediating role of social media self-view (interdependent vs. independent self), 2) how main effect and mediated relationship are different between two groups divided by participants’ time spent on social media (high vs. low: ±1 SD) and 3) how the type of social media interaction (post vs. “like”) affects handbag choice between social and functional luxury-superior option.

This study explored the effects of note-taking training on Korean college students’ notes during academic English listening tests. A total of 61 college students were randomly assigned to two different groups: Group A that later received training in note-taking strategy and Group B that did not. Group A received note-taking strategy training on three separate times, totaling 60 minutes (30 minutes, 15 minutes, and 15 minutes) that spread out over two months. The two groups took listening tests before and after Group A was trained. The results showed the positive effects of the notetaking training in relation with the groups’ note-taking behaviors. After training, the trained group used more and frequent notes whereas the untrained group’s number of notes decreased. Individual students who drastically increased the number of notes after training (in Test II) showed more systemic framework of notes for Test II than before training (in Test I). The present study is meaningful in that it utilized the different analyzing methods on the quality of notes compared with previous studies.

본 연구는 충남도립공원(덕산도립공원, 칠갑산도립공원, 대둔산도립공원)에 분포하고 있는 산림 식생을 비교 분석하기 위해 2006년부터 2016년까지 실시되었다. 본 연구 조사지의 식생을 식물사회학적 방법으로 분석한 결과, 덕산도립공원은 신갈나무군락, 소나무군락, 굴참나무군락 및 느티나무군락으로 구분되었고, 칠갑산도립공원은 굴참나무군락, 신갈나무군락, 소나무군락 및 서어나무군락으로 구분되었으며, 대둔산도립공원은 신갈나무군락, 굴참나무군락 졸참나무군락, 개서어나무군락, 서어나무군락, 소나무군락 및 상수리나무군락으로 구분되었다. 각 도립공원의 중요치는 덕산도립공원에서 신갈나무가 가장 높았으며(72.35), 다음으로 소나무(70.25), 굴참나무(53.11), 때죽나무(11.44), 산벚나무(11.17), 물푸레나무(10.41) 등의 순으로 나타났으며, 칠갑산도립공원에서는 굴참나무가(73.34) 가장 높았고 다음으로 소나무(58.71), 신갈나무(57.02), 서어나무(18.84), 졸참나무(13.48), 산벚나무(13.31) 등의 순으로 나타났다. 대둔산도립공원은 신갈나무가(57.03) 가장 높았고 다음으로 굴참나무(31.98), 졸참나무(31.53), 소나무(16.80), 개서어나무(16.50), 서어나무(16.07), 쪽동백나무(15.76), 당단풍나무(10.09 ) 등의 순으로 나타났다. 중요치가 높은 주요 분류군에 대한 흉고직경급을 분석한 결과 덕산도립공원에서는 신갈나무, 굴참나무가 정규분포형의 밀도를 나타내고 있어 당분간은 이들 수종의 우점 상태가 계속될 것으로 보인다. 칠갑산도립공원에서는 굴참나무, 신갈나무, 소나무가 정규분포형의 밀도를 나타내고 있어 당분간은 이들 수종의 우점 상태가 계속될 것으로 보이나 서어나무와, 졸참나무의 어린 개체 밀도가 높아 앞으로 이들의 세력이 확장될 것으로 판단된다. 대둔산도립공원은 신갈나무와 굴참나무는 어린개체의 밀도가 높은 역 J자형을 하고 있어 우점 상태가 계속될 것으로 보이며, 개서어나무와 소나무는 어린 개체와 큰 개체의 밀도가 낮고, 중간 개체의 밀도가 높아 정규분포형의 밀도를 나타내고 있는 것으로 보아 당분간은 이들 수종에 의한 우점 상태가 계속될 것으로 판단된다. 서어나무와 졸참나무는 중간이상의 개체와 비교해 볼 때 어린 개체의 밀도가 높아 앞으로 이들의 우점도가 증가할 것으로 예상된다.

There are many different types of heating methods in the world. Most of these heating methods are through radiation and convection. These heating types emphasize insulation because it is important to maintain the indoor air temperature. In contrast, the ondol, emphasizes thermal storage in the floor because it heats conduction. In other words it heats through direct contact. This unique heating method has created a unique interior environment. Activities have to occur close to the floor so that people may come in direct contact with the heat, thereby influencing the cultural development of the Korean people. The ondol has also created an interior environment where it is warmer near the floor than the ceiling in contrast to other heating systems where the area close to the ceiling is warmer. This environment is inline with the optimal healthy conditions the Koreans prefer, the warm feet cool head environment.