• Title/Summary/Keyword: alternative testing methods

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Assessment of the Dermal and Ocular Irritation Potential of Lomefloxacin by Using In Vitro Methods

  • Ahn, Jun-Ho;Eum, Ki-Hwan;Lee, Mi-Chael
    • Toxicological Research
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    • v.26 no.1
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    • pp.9-14
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    • 2010
  • The evaluation of eye and skin irritation potential is essential to ensuring the safety of human in contact with a wide variety of substances. Despite this importance of irritation test, little is known with respect to the irritation potency of lomefloxacin, a fluoroquinolone antibiotic, which has been known to cause phototoxicity with an abnormal reaction of the skin. Thus, to investigate the tendency of lomefloxacin to cause eye and skin irritation, we carried out in vitro eye irritation test using Balb/c 3T3, and in vitro skin irritation test using $KeraSkin^{TM}$ human skin model system. 3T3 neutral red uptake assay has been proposed as a potential replacement alternative for the Draize Eye irritation test. In this study, the $IC_{50}$ value obtained for lomefloxacin was 375 ${\mu}g$. According to the classification model used for determining in vitro categories, lomefloxacin was classified as moderately irritant. For evaluation of skin irritation, engineered epidermal equivalents ($KeraSkin^{TM}$) were subjected to 10 and 25 mg of lomefloxacin for 15 minutes. Tissue damage was assessed by tissue viability evaluation, and by the release of a pro-inflammatory mediator, interleukin- 1${\alpha}$. Lomefloxacin increased the interleukin-1${\alpha}$ release after 15 minutes of exposure and 42 hours of post incubation, although no decrease in viability was observed. Therefore, lomefloxacin is considered to be moderately irritant to skin and eye.

ESTIMATION OF DUCTILE FRACTURE BEHAVIOR INCORPORATING MATERIAL ANISOTROPY

  • Choi, Shin-Beom;Lee, Dock-Jin;Jeong, Jae-Uk;Chang, Yoon-Suk;Kim, Min-Chul;Lee, Bong-Sang
    • Nuclear Engineering and Technology
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    • v.44 no.7
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    • pp.791-798
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    • 2012
  • Since standardized fracture test specimens cannot be easily extracted from in-service components, several alternative fracture toughness test methods have been proposed to characterize the deformation and fracture resistance of materials. One of the more promising alternatives is the local approach employing the SP(Small Punch) testing technique. However, this process has several limitations such as a lack of anisotropic yield potential and tediousness in the damage parameter calibration process. The present paper investigates estimation of ductile fracture resistance(J-R) curve by FE(Finite Element) analyses using an anisotropic damage model and enhanced calibration procedure. In this context, specific tensile tests to quantify plastic strain ratios were carried out and SP test data were obtained from the previous research. Also, damage parameters constituting the Gurson-Tvergaard-Needleman model in conjunction with Hill's 48 yield criterion were calibrated for a typical nuclear reactor material through a genetic algorithm. Finally, the J-R curve of a standard compact tension specimen was predicted by further detailed FE analyses employing the calibrated damage parameters. It showed a lower fracture resistance of the specimen material than that based on the isotropic yield criterion. Therefore, a more realistic J-R curve of a reactor material can be obtained effectively from the proposed methodology by taking into account a reduced load-carrying capacity due to anisotropy.

High Efficacy of Levofloxacin-Dexlansoprazole-Based Quadruple Therapy as a First Line Treatment for Helicobacter pylori Eradication in Thailand

  • Prapitpaiboon, Hatainuch;Mahachai, Varocha;Vilaichone, Ratha-Korn
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.10
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    • pp.4353-4356
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    • 2015
  • Background: Levofloxacin is an effective medication for second line Helicobacter pylori (H. pylori) eradication. However, limited studies have approved its use as an effective antibiotic in first line therapy. Dexlansoprazole is a new PPI and lacks of evidence in support of a role in H. pylori eradication. This study was designed to evaluate efficacy of levofloxacin-dexlansoprazole-based quadruple therapy for H. pylori eradication in Thailand. Materials and Methods: This prospective randomized control study was performed during June 2014 to December 2014. H. pylori infected gastritis patients were randomized to receive 7- or 14-day levofloxacin-dexlansoprazole based on quadruple therapy (levofloxacin 500 mg OD, dexlansoprazole 60 mg bid, clarithromycin MR 1000 mg OD, bismuth subsalicylate 1048 mg bid). CYP2C19 genotyping and antibiotic susceptibility tests were conducted for all patients. A 13C urea breath test was performed to confirm H. pylori eradication at least 4 weeks after treatment. Results: A total of 100 patients were enrolled, comprising 44 males and 56 females (mean age of 52.6 years). Eradication rate by PP analysis was 85.7% (42/49) with the 7-day regimen and 98% (48/49) with the 14-day regimen (85.7% vs 98%; p-value=0.059). ITT analysis was 84% and 96% with 7- and 14-day regimens, respectively (84% vs 96%; p-value=0.092). Antibiotic susceptibility testing demonstrated 35.1% resistance to metronidazole, 18.3% to clarithromycin, and 13.5% to levofloxacin. CYP2C19 genotyping revealed 54.1% RM, 34.7% IM and 11.2% PM. The 14-day regimen provided 100% eradication in patients with clarithromycin or dual clarithromycin and metronidazole H. pylori resistant strains. Moreover, the eradication rate was 96.6% in patients with CYP2C19 genotype RM. Conclusions: The 14-day levofloxacin-dexlansoprazole based quadruple therapy provides high H. pylori eradication regardless of CYP2C19 genotype, clarithromycin or dual clarithromycin and metronidazole resistant strains. This regimen could be use as an alternative first line therapy for H. pylori eradication in Thailand.

Tensile bond strength between auto-polymerized acrylic resin and acrylic denture teeth treated with MF-MA solution

  • Thongrakard, Ticha;Wiwatwarrapan, Chairat
    • The Journal of Advanced Prosthodontics
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    • v.8 no.4
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    • pp.285-289
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    • 2016
  • PURPOSE. This study evaluated the effect of chemical surface treatment using methyl formate-methyl acetate (MF-MA) solution on the tensile bond strength between acrylic denture teeth and auto-polymerized acrylic resin. MATERIALS AND METHODS. Seventy maxillary central incisor acrylic denture teeth for each of three different brands (Yamahachi New Ace; Major Dent; Cosmo HXL) were embedded with incisal edge downwards in auto-polymerized resin in polyethylene pipes and ground with silicone carbide paper on their ridge lap surfaces. The teeth of each brand were divided into seven groups (n=10): no surface treatment (control group), MF-MA solution at a ratio of 25:75 (v/v) for 15 seconds, 30 seconds, 60 seconds, 120 seconds, 180 seconds, and MMA for 180 seconds. Auto-polymerized acrylic resin (Unifast Trad) was applied to the ground surface and polymerized in a pressure cooker. A tensile strength test was performed with a universal testing machine. Statistical analysis of the results was performed using two-way analysis of variance (ANOVA) and post-hoc Dunnett T3 test (${\alpha}$=.05). RESULTS. The surface treatment groups had significantly higher mean tensile bond strengths compared with the control group (P<.05) when compared within the same brand. Among the surface treatment groups of each brand, there were no significantly different tensile bond strengths between the MF-MA groups and the MMA 180 second group (P>.05), except for the Yamahachi New Ace MF-MA 180-second group (P<.05). CONCLUSION. 15-second MF-MA solution can be an alternative chemical surface treatment for repairing a denture base and rebonding acrylic denture teeth with auto-polymerized acrylic resin, for both conventional and cross-linked teeth.

A Study for Security-Based Medical Information Software Architecture Design Methodology (의료정보보안 기반 소프트웨어 아키텍처 설계방법)

  • Kim, Jeom Goo;Noh, SiChoon
    • Convergence Security Journal
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    • v.13 no.6
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    • pp.35-41
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    • 2013
  • What is an alternative to medical information security of medical information more secure preservation and safety of various types of security threats should be taken, starting from the software design. Interspersed with medical information systems medical information to be able to integrate the real-time exchange of medical information must be reliable data communication. The software architecture design of medical information systems and sharing of medical information security issues and communication phase allows the user to identify the requirements reflected in the software design. Software framework design, message standard design, design a web-based inter-process communication procedures, access control algorithm design, architecture, writing descriptions, evaluation of various will procedure the establishing architecture. The initial decision is a software architecture design, development, testing, maintenance, ongoing impact. In addition, the project will be based on the decision in detail. Medical information security method based on the design software architecture of today's medical information security has become an important task of the framework will be able to provide.

Methylation Abnormality in Body Fluid Cytology: A Supplemental Molecular Marker for the Diagnosis of Malignant Mesothelioma (체액 세포 도말 검사에서 메틸화 이상이 악성 중피종 진단의 부가적인 분자 표지자로서의 기능)

  • Song, Joon-Seon;Jung, Jin-Kyung;Kang, Ji-Hye;Hwang, Il-Seon;Jang, Se-Jin
    • The Korean Journal of Cytopathology
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    • v.19 no.2
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    • pp.126-135
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    • 2008
  • Malignant mesothelioma (MM) is a highly lethal neoplasm arising in pleura and the peritoneum and a rapid and accurate diagnosis is crucial for treatment of the disease. However, the sensitivity of cytological analysis using pleural or ascitic fluid is relatively low, yielding an accurate diagnosis in only $32{\sim}79%$ of cases. We tested the diagnostic value of epigenetic alterations in body fluid cytology as a supplement to conventional methods. Paraffin-embedded tissue blocks from 21 MM patients and associated body fluid cytology slides considered no evidence of malignancy were used to test for epigenetic alteration. Using methylation-specific PCR, we detected methylation of RASSF1A and p16 in 47.6% (10/21) of both surgically resected tumor samples, respectively. Body fluid samples of MM also showed abnormal methylation of RASSF1A and p16INK4a genes in 38.1% (8/21) and 33.3% (7/21) of cases. The concordance in the rates of RASSF1A and p16INK4a gene-methylation abnormalities determined from cytology samples and tissue samples were 61.9% (13/21) and 66.7% (14/21), respectively. Combining both genes increases the sensitivity of the test to 57.1 % (12 of 21) of cases. Our results suggest that testing for methylation abnormalities in selected individual genes or gene combinations has diagnostic value as an alternative or adjunct method to conventional cytological diagnosis.

Generating Reduced Test Model of Embedded Software using Partial Order Techniques (부분순서 관계를 이용한 내장 소프트웨어의 축소된 테스트 모델 생성)

  • 이남희;차성덕
    • Journal of KIISE:Software and Applications
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    • v.30 no.11
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    • pp.1015-1024
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    • 2003
  • In [1] we proposed a method to generate a test model (GFSM) from a set of scenarios of embedded software. Each scenario describes the interaction sequences for an external input event. Although these external events are generated and accepted alternatively and concurrently by embedded software, we considered only the alternative relations. In this paper, we describe an improved algorithm to generate GFSM from concurrent scenarios, and propose methods to reduce the number of transitions in the GFSM. The first is the synchronous interpretation of message passing instead of asynchronous one considering the real behavior of tasks in embedded software. The others apply the partial order techniques to the GFSM using independent regions. We apply the method to generate a reduced GFSM of embedded software running on a digital TV.

Toxicity Prediction using Three Quantitative Structure-activity Relationship (QSAR) Programs (TOPKAT®, Derek®, OECD toolbox) (TOPKAT®, Derek®, OECD toolbox를 활용한 화학물질 독성 예측 연구)

  • Lee, Jin Wuk;Park, Seonyeong;Jang, Seok-Won;Lee, Sanggyu;Moon, Sanga;Kim, Hyunji;Kim, Pilje;Yu, Seung Do;Seong, Chang Ho
    • Journal of Environmental Health Sciences
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    • v.45 no.5
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    • pp.457-464
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    • 2019
  • Objectives: Quantitative structure-activity relationship (QSAR) is one of the effective alternatives to animal testing, but its credibility in terms of toxicity prediction has been questionable. Thus, this work aims to evaluate its predictive capacity and find ways of improving its credibility. Methods: Using $TOPKAT^{(R)}$, OECD toolbox, and $Derek^{(R)}$, all of which have been applied world-wide in the research, industrial, and regulatory fields, an analysis of prediction credibility markers including accuracy (A), sensitivity (S), specificity (SP), false negative (FN), and false positive (FP) was conducted. Results: The multi-application of QSARs elevated the precision credibility relative to individual applications of QSARs. Moreover, we found that the type of chemical structure affects the credibility of markers significantly. Conclusions: The credibility of individual QSAR is insufficient for both the prediction of chemical toxicity and regulation of hazardous chemicals. Thus, to increase the credibility, multi-QSAR application, and compensation of the prediction deviation by chemical structure are required.

Evaluation of mode-shape linearization for HFBB analysis of real tall buildings

  • Tse, K.T.;Yu, X.J.;Hitchcock, P.A.
    • Wind and Structures
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    • v.18 no.4
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    • pp.423-441
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    • 2014
  • The high frequency base balance (HFBB) technique is a convenient and relatively fast wind tunnel testing technique for predicting wind-induced forces for tall building design. While modern tall building design has seen a number architecturally remarkable buildings constructed recently, the characteristics of those buildings are significantly different to those that were common when the HFBB technique was originally developed. In particular, the prediction of generalized forces for buildings with 3-dimensional mode shapes has a number of inherent uncertainties and challenges that need to be overcome to accurately predict building loads and responses. As an alternative to the more conventional application of general mode shape correction factors, an analysis methodology, referred to as the linear-mode-shape (LMS) method, has been recently developed to allow better estimates of the generalized forces by establishing a new set of centers at which the translational mode shapes are linear. The LMS method was initially evaluated and compared with the methods using mode shape correction factors for a rectangular building, which was wind tunnel tested in isolation in an open terrain for five incident wind angles at $22.5^{\circ}$ increments from $0^{\circ}$ to $90^{\circ}$. The results demonstrated that the LMS method provides more accurate predictions of the wind-induced loads and building responses than the application of mode shape correction factors. The LMS method was subsequently applied to a tall building project in Hong Kong. The building considered in the current study is located in a heavily developed business district and surrounded by tall buildings and mixed terrain. The HFBB results validated the versatility of the LMS method for the structural design of an actual tall building subjected to the varied wind characteristics caused by the surroundings. In comparison, the application of mode shape correction factors in the HFBB analysis did not directly take into account the influence of the site specific characteristics on the actual wind loads, hence their estimates of the building responses have a higher variability.

Biomechanical Study of Posterior Pelvic Fixations in Vertically Unstable Sacral Fractures: An Alternative to Triangular Osteosynthesis

  • Chaiyamongkol, Weera;Kritsaneephaiboon, Apipop;Bintachitt, Piyawat;Suwannaphisit, Sitthiphong;Tangtrakulwanich, Boonsin
    • Asian Spine Journal
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    • v.12 no.6
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    • pp.967-972
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    • 2018
  • Study Design: Biomechanical study. Purpose: To investigate the relative stiffness of a new posterior pelvic fixation for unstable vertical fractures of the sacrum. Overview of Literature: The reported operative fixation techniques for vertical sacral fractures include iliosacral screw, sacral bar fixations, transiliac plating, and local plate osteosynthesis. Clinical as well as biomechanical studies have demonstrated that these conventional techniques are insufficient to stabilize the vertically unstable sacral fractures. Methods: To simulate a vertically unstable fractured sacrum, 12 synthetic pelvic models were prepared. In each model, a 5-mm gap was created through the left transforaminal zone (Denis zone II). The pubic symphysis was completely separated and then stabilized using a 3.5-mm reconstruction plate. Four each of the unstable pelvic models were then fixed with two iliosacral screws, a tension band plate, or a transiliac fixation plus one iliosacral screw. The left hemipelvis of these specimens was docked to a rigid base plate and loaded on an S1 endplate by using the Zwick Roell z010 material testing machine. Then, the vertical displacement and coronal tilt of the right hemipelves and the applied force were measured. Results: The transiliac fixation plus one iliosacral screw constructions could withstand a force at 5 mm of vertical displacement greater than the two iliosacral screw constructions (p=0.012) and the tension band plate constructions (p=0.003). The tension band plate constructions could withstand a force at $5^{\circ}$ of coronal tilt less than the two iliosacral screw constructions (p=0.027) and the transiliac fixation plus one iliosacral screw constructions (p=0.049). Conclusions: This study proposes the use of transiliac fixation in addition to an iliosacral screw to stabilize vertically unstable sacral fractures. Our biomechanical data demonstrated the superiority of adding transiliac fixation to withstand vertical displacement forces.