• Journal of Korean Dental Science
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• 제16권1호
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• pp.47-62
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• 2023

Purpose: We aimed to investigate the objective cutoff values of unstimulated flow rates (UFR) and stimulated salivary flow rates (SFR) in patients with xerostomia and to present an optimal machine learning model with a classification and regression tree (CART) for all ages. Materials and Methods: A total of 829 patients with oral diseases were enrolled (591 females; mean age, 59.29±16.40 years; 8~95 years old), 199 patients with xerostomia and 630 patients without xerostomia. Salivary and clinical characteristics were collected and analyzed. Result: Patients with xerostomia had significantly lower levels of UFR (0.29±0.22 vs. 0.41±0.24 ml/min) and SFR (1.12±0.55 vs. 1.39±0.94 ml/min) (P<0.001), respectively, compared to those with non-xerostomia. The presence of xerostomia had a significantly negative correlation with UFR (r=-0.603, P=0.002) and SFR (r=-0.301, P=0.017). In the diagnosis of xerostomia based on the CART algorithm, the presence of stomatitis, candidiasis, halitosis, psychiatric disorder, and hyperlipidemia were significant predictors for xerostomia, and the cutoff ranges for xerostomia for UFR and SFR were 0.03~0.18 ml/min and 0.85~1.6 ml/min, respectively. Conclusion: Xerostomia was correlated with decreases in UFR and SFR, and their cutoff values varied depending on the patient's underlying oral and systemic conditions.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제49권3호
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• pp.135-141
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• 2023

Objectives: This study aimed to develop and validate machine learning (ML) models using H₂O-AutoML, an automated ML program, for predicting medication-related osteonecrosis of the jaw (MRONJ) in patients with osteoporosis undergoing tooth extraction or implantation. Patients and Methods: We conducted a retrospective chart review of 340 patients who visited Dankook University Dental Hospital between January 2019 and June 2022 who met the following inclusion criteria: female, age ≥55 years, osteoporosis treated with antiresorptive therapy, and recent dental extraction or implantation. We considered medication administration and duration, demographics, and systemic factors (age and medical history). Local factors, such as surgical method, number of operated teeth, and operation area, were also included. Six algorithms were used to generate the MRONJ prediction model. Results: Gradient boosting demonstrated the best diagnostic accuracy, with an area under the receiver operating characteristic curve (AUC) of 0.8283. Validation with the test dataset yielded a stable AUC of 0.7526. Variable importance analysis identified duration of medication as the most important variable, followed by age, number of teeth operated, and operation site. Conclusion: ML models can help predict MRONJ occurrence in patients with osteoporosis undergoing tooth extraction or implantation based on questionnaire data acquired at the first visit.

• 한국안전학회지
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• 제39권1호
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• pp.16-26
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• 2024

This study aims to introduce a method for risk assessment analysis aimed at preventing electrical fires within the manufacturing industry. Initially, we provided a functional block diagram illustrating the electrical equipment employed in various processes within a food manufacturing company in Chungcheongbuk-do. Subsequently, we categorized the components of each machine outlined in the functional block diagram and determined the priority of failure for each classified component. Upon implementing the model in the frying process of the food manufacturing company, specific components, including MC, motor, mixer heater, electric wiring, and terminal block, exhibit a risk priority number (RPN) of 40 or higher. This identified an electrical issue within the manufacturing process and environment. Consequently, we propose a methodology to identify latent failure modes that could escalate into fires or systemic issues if not promptly addressed. It is essential to note that while the FMEA presented in this study may not immediately impact food manufacturing, its applicability extends to various workplaces.

• IMMUNE NETWORK
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• 제16권5호
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• pp.305-310
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• 2016

In this study, we compared two different tumor cell vaccines for their induction of anti-tumor immunity; one was a tumor cell clone expressing a membrane-bound form of IL-12 p35 subunit (mbIL-12 p35 tumor clone), and the other was a tumor clone expressing heterodimeric IL-12 as a single chain (mb-scIL-12 tumor clone). The stimulatory effect of mb-scIL-12 on the proliferation of ConA-activated splenocytes was higher than that of mbIL-12 p35 in vitro. However, the stimulatory effect of mbIL-12 p35 was equivalent to that of recombinant soluble IL-12 (3 ng/ml). Interestingly, both tumor clones (mbIL-12 p35 and mb-scIL-12) showed similar tumorigenicity and induction of systemic anti-tumor immunity in vivo, suggesting that tumor cell expression of the membrane-bound p35 subunit is sufficient to induce anti-tumor immunity in our tumor vaccine model.

• 유통과학연구
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• 제22권9호
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• pp.107-117
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• 2024

Purpose: This research aims to contribute to the search for strategies on innovation in chatbot services in airline distribution industry. Personal and systemic characteristics of chatbot were derived together. The extended technology acceptance model theory was applied. The effects of perceived ease of use, usefulness, and intention to use chatbot from the user's perspective were empirically analyzed. Research design, data and methodology: Through an online survey, 309 people who have experience using chatbot services in airline distribution industry responded. AMOS 18.0 was used to analyze the data. Results: The hypothesis that personal characteristics will positively influence perceived ease and perceived usefulness was tested. Self-efficacy and user's innovativeness were shown have a significant effect on both perceived ease and perceived usefulness. System characteristics present a positive effect on perceived ease and perceived usefulness was tested. Consistency and familiarity were found to affect perceived ease and perceived usefulness. Perceived ease of use and perceived usefulness show a positive effect on intention to continue using chatbot service. Conclusions: When building an airline chatbot service in airline distribution industry, it is necessary to consider systematic characteristics, ease of use, and usability. It provided practical implications in that it have a significant impact on users' intention to use.

• 동의생리병리학회지
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• 제16권1호
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• pp.124-132
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• 2002

Daebangpung-tang(DBPT) is one of the prescriptions used for the treatment of rheumatoid arthritis(RA) in oriental medicine. The present study aimed to examine the analgesic effect of DBPT on a rat model of CFA-induced arthritis, which is not identical to human auto-immune arthritis although it does have many features in common with RA, and the relation between DBPT-induced analgesia and steroid hormones. CFA-induced arthritis rat model used to test the effect of DBPT was chronic pain model. After the induction of arthritis, rats subsequently showed a reduced stepping force of the affected limb for at least the next 18 days. The reduced stepping force of the limb was presumably due to a painful knee, since oral injection of indomethacin produced temporary improvement of weight bearing. DBPT dissolved in water was orally administrated. After the treatment, behavioral tests measuring stepping force were periodically conducted during the next 4 hours. DBPT produce significant improvement of stepping force of the hindlimb affected by the arthritis lasting at least 3 hours. The magnitude of this improvement was equivalent to that obtained after an oral injection of 3mg/kg of indomethacin and this improvement of stepping force was interpreted as an analgesic effect. The reduced stepping force was divided into three stages(10-30g, 30-50g, and 50-70g). All experiments was performed at 50-70g of stepping force, since both DBPT and indomethacin showed the most excellent analgesic effect at 50-70g of stepping force. DBPT produced the improvement of stepping force of the affected hindlimb in a dose-dependent manner and showed analgesic effect on neuropathic pain as well. DBPT-induced analgesic effect could not be blocked by systemic injection of steroid antagonist mifepristone. The present study suggest 1) that DBPT produces a potent analgesic effect on the chronic knee arthritis pain model in the rat and 2) that steroids system does not mediate DBPT-induced analgesia.

• IMMUNE NETWORK
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• 제7권1호
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• pp.18-25
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• 2007

Background: Although glucocorticoids (GCs) are effective in controlling asthma in the majority of patients, a subset of asthmatics fails to demonstrate a satisfactory response, even to systemic GC therapy. This population is referred to as being "steroid-resistant". The actual mechanism underlying steroid resistance in asthma remains to be elucidated. Methods: We have investigated how dexamethasone (DEX) regulates asthmatic phenotypes in a murine model of asthma, in which mice received i.p. immunization twice, followed by two bronchoprovocations with aerosolized OVA with a one-week interval, which we have recently described. Results: Pretreatment with DEX resulted in an inhibition of NF-${\kappa}B$ activation in asthmatic lungs, and also inhibited bronchoalveolar lavage (BAL) levels of NF-${\kappa}B$-dependent cytokines such as TNF-${\alpha}$ and CC chemokines [eotaxin and monocyte chemotactic protein (MCP)-1]. DEX was effective in suppressing airway hyperresponsiveness (AHR) at 10 h, Th2-dependent asthmatic phenotypes such as airway eosinophilia, BAL levels of Th2 cytokines (IL-5 and IL-13), and mucin production. However, DEX failed to suppress BAL levels of CXC chemokines [macrophage inflammatory protein-2 (MIP-2) and keratinocyte-derived chemokine (KC)] and airway neutrophilia. Conclusion: Airway neutrophilia is among the phenomena observed in patients with severe GC-resistant asthma. This study will provide insight into the molecular basis for airway neutrophila seen in steroid-resistant asthma. Further studies are required to delineate the underlying mechanism of CXC chemokine expression in asthma.

• 정보교육학회논문지
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• 제18권4호
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• pp.529-540
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• 2014

우리는 수 과학 영재 고등학생들의 정보과학 창의성 향상을 위한 효과적인 정보과학 교수-학습 방법을 제안하였다. 학생들은 현실적 응용문제를 해결하는 정보과학 팀 프로젝트의 수행을 통하여 창의적 문제해결 능력과 팀워크 능력을 향상할 수 있다. 이러한 교육목표를 효과적으로 달성하기 위하여 기본과정과 응용과정으로 구성되는 2단계 정보과학 수업 방법과 체계적 프로젝트 수행 단계를 설계하고, 소규모 협력 학습 전략과 입체적 평가 방안을 적용하였다. 논문에서 제안한 프로젝트 기반 교수-학습 방법의 학습 효과를 분석한 결과, 정보과학 창의성의 지적 정의적 및 사회적 영역에서의 효과적인 교육 목표 달성을 확인할 수 있었다.

• Archives of Plastic Surgery
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• 제33권5호
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• pp.621-626
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• 2006

Purpose: Erythropoietin is traditionally known to regulate erythropoiesis, but recently its protective effect against ischemia-reperfusion injury has been studied mainly in cardiovascular and neuronal systems. This study was planned to investigate the effects of recombinant human erythropoietin on ischemia-reperfusion injury in rat TRAM flap model. Methods: Superiorly based TRAM flap was elevated and ischemic insult was given for four hours. Thirty minutes before reperfusion, single dose recombinant human Erythropoietin(5000IU/kg) was injected via intraperitoneal route in the treatment group. At 24 hours postoperatively, systemic neutrophil count, tissue myeloperoxidase activity, malonyldialdehyde amount, nitric oxide content, tissue water content and histologic finding of inflammation was evaluated. On 10 days postoperatively, flap survival rate, angiogenesis and change in hematocrit level was evaluated. Results: Tissue nitric oxide level was significantly higher and myeloperoxidase activity was significantly lower in the treatment group 24 hours after reperfusion. Tissue water content was significantly lower in the treatment group. Perivascular neutrophil infiltration and intravascular adhesion was marked in the control group. Mean flap survival after ten days was 69% in the treatment group, and 47% in the control group, demonstrating a significant difference. Neovascularization in the treatment group also outnumbered the control group. No significant hematocrit rise was noted ten days after erythropoietin administration. Conclusion: Recombinant human Erythropoietin improved flap survival in ischemia-reperfusion injured rat TRAM flaps, at least partially owing to suppressed inflammation, increased nitric oxide, and enhanced angiogenesis.

• Journal of Microbiology and Biotechnology
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• 제28권9호
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• pp.1413-1425
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• 2018

Shiga toxins (Stxs) are the main virulence factors expressed by the pathogenic Stx-producing bacteria, namely, Shigella dysenteriae serotype 1 and certain Escherichia coli strains. These bacteria cause widespread outbreaks of bloody diarrhea (hemorrhagic colitis) that in severe cases can progress to life-threatening systemic complications, including hemolytic uremic syndrome (HUS) characterized by the acute onset of microangiopathic hemolytic anemia and kidney dysfunction. Shiga toxicosis has a distinct pathogenesis and animal models of Stx-associated HUS have allowed us to investigate this. Since these models will also be useful for developing effective countermeasures to Stx-associated HUS, it is important to have clinically relevant animal models of this disease. Multiple studies over the last few decades have shown that mice injected with purified Stxs develop some of the pathophysiological features seen in HUS patients infected with the Stx-producing bacteria. These features are also efficiently recapitulated in a non-human primate model (baboons). In addition, rats, calves, chicks, piglets, and rabbits have been used as models to study symptoms of HUS that are characteristic of each animal. These models have been very useful for testing hypotheses about how Stx induces HUS and its neurological sequelae. In this review, we describe in detail the current knowledge about the most well-studied in vivo models of Stx-induced HUS; namely, those in mice, piglets, non-human primates, and rabbits. The aim of this review is to show how each human clinical outcome-mimicking animal model can serve as an experimental tool to promote our understanding of Stx-induced pathogenesis.