• Restorative Dentistry and Endodontics
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• v.49 no.2
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• pp.16.1-16.10
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• 2024

Objectives: This cross-sectional study evaluated the prevalence of apical periodontitis (AP) and the technical quality of root canal fillings in an adult Kuwaiti subpopulation using cone-beam computed tomography (CBCT) images. Materials and Methods: Two experienced examiners analyzed 250 CBCT images obtained from Kuwaiti patients aged 15-65 years who attended government dental specialist clinics between January 2019 and September 2020. The assessment followed the radiographic scoring criteria proposed by De Moor for periapical status and the technical quality of root canal filling. Chi-square and Fisher's exact tests were used for statistical analysis, with significance level set at p < 0.05. Results: Among the 2,762 examined teeth, 191 (6.91%) exhibited radiographic signs of AP, and 176 (6.37%) had undergone root canal filling. AP prevalence in root canal-treated teeth was 32.38%, with a significant difference between males and females. Most of the endodontically treated teeth exhibited adequate root canal filling (71.5%). Conclusions: The study demonstrated a comparable prevalence of AP and satisfactory execution of root canal treatment compared to similar studies in different countries.

• Bulletin of the Korean Chemical Society
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• v.24 no.8
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• pp.1181-1187
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• 2003

Condensation of 4-cyano-5,6-dimethyl-3-pyridazinone 1 with aromatic aldehydes gave the novel styryl derivatives 2a-c. Refluxing of compound 2a with phosphorus oxychloride furnished 3-chloropyridazine derivative 3. Compound 3 was reacted with thiourea and produced pyridazine-3(2H)thione 4. Thieno[2,3-c]- pyridazines 5a-e were achieved by cycloalkylation of compound 4 with halocompounds in methanol under reflux and in the presence of sodium methoxide. Also, refluxing of compound 4 with N-substituted chloroacetamide in the presence of potassium carbonate afforded thienopyridazines 6a-e. Cyclization of compound 6 with some electrophilic reagents as carbon disulfide and triethyl orthoformate furnished the novel pyrimido[4',5':4,5]thieno[2,3-c]pyridazines 12 and 13a-c, respectively. Diazotisation of compound 6 with sodium nitrite in acetic acid produced the pyridazino[4',3':4,5]thieno[3,2-d][1,2,3]triazines 14a-c. Ternary condensation of compound 1, aromatic aldehydes and malononitrile in ethanol containing piperidine under reflux afforded the novel phthalazines 16a-c. Compound 3 was subjected to some nucleophilic substitution reactions with amines and sodium azide and formed the aminopyridazines 17a, b and tetrazolo[1,5-b]-pyridazine 19, respectively. The structures of the synthesized compounds were established by elemental and spectral analyses.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.13 no.4
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• pp.58-75
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• 2005

본 연구는 국적항공사를 포함하여 지난 1998${\sim}$2001년까지 세계 주요 항공사들의 생산성의 변화 추이가 어떻게 전개되었고, 어떤 요인에 의해 영향을 받았는지를 분석하였다. 특히, 1997년 금융위기 이후 생산성의 변화에 주안점을 두었다. 추정결과, 우선 세계 주요 항공사들은 1998${\sim}$2001년 기간 동안 약 0.3%의 생산성 하락을 기록하였고, 이러한 생산성의 변화는 생산 프론티어에 비해 0.9% 악화된 반면, 산출물을 생산하는 기술 수준은 0.6% 확대된 것으로 분석되었다. 다음으로, 항공사의 '유상톤키로미터' 기준에 의한 규모별 생산성 증가율은 소형규모(group1)와 대형규모(group6)에 속한 항공사들에서 각각 3.5%, 2.1% 하락한 것으로 나타났다. 반면, 중형사들은 생산성의 증가가 이루어진 것으로 제시되었다. 또한, 기간별로는 1997년 금융위기 이후 1998년과 1999년은 각각 1.5%, 0.2%의 생산성 하락을 보였다가, 2000년은 1.7% 생산성이 다소 향상되었으며, 2001년 다시 1.2%의 생산성 하락을 보이고 있다. 마지막으로 항공사별로는 동 기간 동안 아시아지역 항공사들(AAR, SIA, ANA 등)은 생산상 향상을 가져온 반면, 미국 항공사들(UAL, AAL 등)은 생산성 하락을 가져온 것을 알 수 있다. 국적항공사의 경우에는 KAL은 1998${\sim}$1999년 기간 동안은 생산성 하락을 가져왔으나, 2000${\sim}$2001년은 큰 폭의 생산성 향상을 가져왔다. AAR은 1998년 생산성 하락이 이루어진 이후 1999년부터는 높은 생산성 향상이 이루어졌다.

• The Transactions of the Korea Information Processing Society
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• v.5 no.1
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• pp.128-136
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• 1998

TTCN(Tree and Tabular Combined Notation), as an international standard, provides a concept and notation to describe a protocol test specification. In this paper, we explain some considerations on each components of Abstract Test Suite and propose naming conventions for Constraints and Test Cases based on the experience of describing Test Suite for real protocol. We also analyze some problems on real application of Test Suite and propose an approach to avoiding such problems in the stage of Test Suite specification. In this paper, we use the SSCOP(Service Specific Connection Oriented Protocol) protocol, that is a sub-layer of ATM Forum UNI 3.1 protocol stack, as an example to proposals on naming conventions on Constraints and Test Cases.

• Journal of Communications and Networks
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• v.10 no.3
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• pp.316-330
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• 2008

This paper proposes a novel method for transporting various types of user traffic effectively over the next generation network called integrated services digital network 3 (ISDN3) (or quantum network) using quantum packets. Basically, a quantum packet comprises one or more 53-byte quanta as generated by a "quantumization" process. While connection-oriented traffic is supported by fixed-size quantum packets each with one quantum to emulate circuit switching, connectionless traffic (e.g., IP packets and active packets) is carried by variable-size quantum packets with multiple quanta to support store-and-forward switching/routing. Our aim is to provide frame-like or datagram-like services while enabling cell-based multiplexing. The quantum packet method also establishes a flexible and extensible framework that caters for future packetization needs while maintaining backward compatibility with ATM. In this paper, we discuss the design of the quantum packet method, including its format, the "quantumization" process, and support for different types of user traffic. We also present an analytical model to evaluate the consumption of network resources (or network costs) when quantum packets are employed to transfer loss-sensitive data using three different approaches: cut-through, store-and-forward and ideal. Close form mathematical expressions are obtained for some situations. In particular, in terms of network cost, we discover two interesting equivalence phenomena for the cut-through and store-and-forward approaches under certain conditions and assumptions. Furthermore, analytical and simulation results are presented to study the system behavior. Our analysis provides valuable insights into the. design of the ISDN3/quantum network.

• Parasites, Hosts and Diseases
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• v.51 no.2
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• pp.165-175
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• 2013

The fear that schistosomes will become resistant to praziquantel (PZQ) motivates the search for alternatives to treat schistosomiasis. The antimalarials quinine (QN) and halofantrine (HF) possess moderate antischistosomal properties. The major metabolic pathway of QN and HF is through cytochrome P450 (CYP) 3A4. Accordingly, this study investigates the effects of CYP3A4 inhibitor, ketoconazole (KTZ), on the antischistosomal potential of these quinolines against Schistosoma mansoni infection by evaluating parasitological, histopathological, and biochemical parameters. Mice were classified into 7 groups: uninfected untreated (I), infected untreated (II), infected treated orally with PZQ (1,000 mg/kg) (III), QN (400 mg/kg) (IV), KTZ (10 mg/kg)+QN as group IV (V), HF (400 mg/kg) (VI), and KTZ (as group V)+HF (as group VI) (VII). KTZ plus QN or HF produced more inhibition (P<0.05) in hepatic CYP450 (85.7% and 83.8%) and CYT b5 (75.5% and 73.5%) activities, respectively, than in groups treated with QN or HF alone. This was accompanied with more reduction in female (89.0% and 79.3%), total worms (81.4% and 70.3%), and eggs burden (hepatic; 83.8%, 66.0% and intestinal; 68%, 64.5%), respectively, and encountering the granulomatous reaction to parasite eggs trapped in the liver. QN and HF significantly (P<0.05) elevated malondialdehyde levels when used alone or with KTZ. Meanwhile, KTZ plus QN or HF restored serum levels of ALT, albumin, and reduced hepatic glutathione (KTZ+HF) to their control values. KTZ enhanced the therapeutic antischistosomal potential of QN and HF over each drug alone. Moreover, the effect of KTZ+QN was more evident than KTZ+HF.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.5
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• pp.9-16
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• 2017

Recent advances in healthcare technologies along with improved medical care have led to a steady increase in life expectancy over the past few decades. As a result, the world population is aging rapidly. Various researches have been carried out to provide information and communication technologies based solutions that enhance the well-being of elderly people and provide them with a well margin of independency in their daily life. Ambient assisted living can be defined as the use of information and communication technologies in a person's daily living and working environment to enable them to stay active longer, remain socially connected and live independently into old age. Since the information transmitted in ambient assisted living systems is very sensitive, the security and privacy of such data are becoming important issues that must be dealt with. In this paper, we propose a novel lightweight authentication protocol for the ambient assisted living systems. The proposed authentication protocol not only supports several important security requirements needed by the ambient assisted living systems, but can also withstand various types of attacks. In addition, the security analysis results show that the proposed authentication protocol is more efficient and secure than the existing authentication protocols.

• Ocean Systems Engineering
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• v.10 no.3
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• pp.243-266
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• 2020

In-place analysis for offshore platforms is required to make proper design for new structures and true assessment for existing structures. In addition, ensure the structural integrity of platforms components under the maximum and minimum operating loads and environmental conditions. In-place analysis was carried out to verify the robustness and capability of structural members with all appurtenances to support the applied loads in either operating condition or storm conditions. A nonlinear finite element analysis is adopted for the platform structure above the seabed and the pile-soil interaction to estimate the in-place behavior of a typical fixed offshore platform. The SACS software is utilized to calculate the natural frequencies of the model and to obtain the response of platform joints according to in-place analysis then the stresses at selected members, as well as their nodal displacements. The directions of environmental loads and water depth variations have an important effect on the results of the in-place analysis behavior. The influence of the soil-structure interaction on the response of the jacket foundation predicts is necessary to estimate the loads of the offshore platform well and real simulation of offshore foundation for the in-place analysis. The result of the study shows that the in-place response investigation is quite crucial for safe design and operation of offshore platform against the variation of environmental loads.

• Earthquakes and Structures
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• v.18 no.4
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• pp.407-421
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• 2020

In-place analysis for offshore platforms is essentially required to make proper design for new structures and true assessment for existing structures, in addition to the structural integrity of platforms components under the maximum and minimum operating loads when subjected to the environmental conditions. In-place analysis have been executed to check that the structural member with all appurtenance's robustness have the capability to support the applied loads in either storm or operating conditions. A nonlinear finite element analysis is adopted for the platform structure above the seabed and pile-soil interaction to estimate the in-place behavior of a typical fixed offshore platform. The SACS software is utilized to calculate the dynamic characteristics of the platform model and the response of platform joints then the stresses at selected members, as well as their nodal displacements. The directions of environmental loads and water depth variations have significant effects in the results of the in-place analysis behavior. The most of bending moment responses of the piles are in the first fourth of pile penetration depth from pile head level. The axial deformations of piles in all load combinations cases of all piles are inversely proportional with penetration depth. The largest values of axial soil reaction are shown at the pile tips levels (the maximum penetration level). The most of lateral soil reactions resultant are in the first third of pile penetration depth from pile head level and approximately vanished after that penetration. The influence of the soil-structure interaction on the response of the jacket foundation predicts that the flexible foundation model is necessary to estimate the force responses demands of the offshore platform with a piled jacket-support structure well.

• The Korean Journal of Pain
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• v.33 no.1
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• pp.81-89
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• 2020

Background: For children with cleft palates, surgeries at a young age are necessary to reduce feeding or phonation difficulties and reduce complications, especially respiratory tract infections and frequent sinusitis. We hypothesized that dexmedetomidine might prolong the postoperative analgesic duration when added to bupivacaine during nerve blocks. Methods: Eighty patients of 1-5 years old were arbitrarily assigned to two equal groups (forty patients each) to receive bilateral suprazygomatic maxillary nerve blocks. Group A received bilateral 0.2 mL/kg bupivacaine (0.125%; maximum volume 4 mL/side). Group B received bilateral 0.2 mL/kg bupivacaine (0.125%) + 0.5 ㎍/kg dexmedetomidine (maximum volume 4 mL/side). Results: The modified children's hospital of Eastern Ontario pain scale score was significantly lower in group B children after 8 hours of follow-up postoperatively (P < 0.001). Mean values of heart rate and blood pressure were significantly different between the groups, with lower mean values in group B (P < 0.001). Median time to the first analgesic demand in group A children was 10 hours (range 8-12 hr), and no patients needed analgesia in group B. The sedation score assessment was higher in children given dexmedetomidine (P = 0.03) during the first postoperative 30 minutes. Better parent satisfaction scores (5-point Likert scale) were recorded in group B and without serious adverse effects. Conclusions: Addition of dexmedetomidine 0.5 ㎍/kg to bupivacaine 0.125% has accentuated the analgesic efficacy of bilateral suprazygomatic maxillary nerve block in children undergoing primary cleft palate repair with less postoperative supplemental analgesia or untoward effects.