• Title/Summary/Keyword: failure patterns

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High Prevalence of Helicobacter pylori Resistance to Clarithromycin: a Hospital-Based Cross-Sectional Study in Nakhon Ratchasima Province, Northeast of Thailand

  • Tongtawee, Taweesak;Dechsukhum, Chavaboon;Matrakool, Likit;Panpimanmas, Sukij;Loyd, Ryan A;Kaewpitoon, Soraya J;Kaewpitoon, Natthawut
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.18
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    • pp.8281-8285
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    • 2016
  • Background: Helicobacter pylori is a cause of chronic gastritis, peptic ulcer disease, and gastric malignancy, infection being a serious health problem in Thailand. Recently, clarithromycin resistant H. pylori strains represent the main cause of treatment failure. Therefore this study aimed to determine the prevalence and pattern of H. pylori resistance to clarithromycin in Suranaree University of Technology Hospital, Suranree University of Technology, Nakhon Ratchasima, Northeastern Thailand, Nakhon Ratchasima province, northeast of Thailand. Materials and Methods: This hospital-based cross-sectional study was carried out between June 2014 and February 2015 with 300 infected patients interviewed and from whom gastric mucosa specimens were collected and proven positive by histology. The gastric mucosa specimens were tested for H. pylori and clarithromycin resistance by 23S ribosomal RNA point mutations analysis using real-time polymerase chain reactions. Correlation of eradication rates with patterns of mutation were analyzed by chi-square test. Results: Of 300 infected patients, the majority were aged between 47-61 years (31.6%), female (52.3%), with monthly income between 10,000-15,000 Baht (57%), and had a history of alcohol drinking (59.3%). Patient symptoms were abdominal pain (48.6%), followed by iron deficiency anemia (35.3%). Papaya salad consumption (40.3%) was a possible risk factor for H. pylori infection. The prevalence of H. pylori strains resistant to clarithromycin was 76.2%. Among clarithromycin-resistant strains tested, all were due to the A2144G point mutation in the 23S rRNA gene. Among mutations group, wild type genotype, mutant strain mixed wild type and mutant genotype were 23.8%, 35.7% and 40.5% respectively. With the clarithromycin-based triple therapy regimen, the efficacy decreased by 70% for H. pylori eradication (P<0.01). Conclusions: Recent results indicate a high rate of H. pylori resistance to clarithromycin. Mixed of wild type and mutant genotype is the most common mutant genotype in Nakhon Ratchasima province, therefore the use of clarithromycin-based triple therapy an not advisable as an empiric first-line regimen for H. pylori eradication in northeast region of Thailand.

Prescribing Patterns of Antihypertensive Drugs by Outpatients with Hypertension in 2007 (고혈압 환자의 혈압강하제 처방양상 - 외래 처방전을 중심으로 -)

  • Sung, Ye-Na;Jang, Sun-Mee;Lim, Do-Hee;Shin, Suk-Youn;Song, Hyun-Jong;Lee, Suk-Hyang
    • Korean Journal of Clinical Pharmacy
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    • v.19 no.2
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    • pp.167-179
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    • 2009
  • Hypertension is one of the most common chronic diseases and it causes cardiovascular and cerebrovascular disease. While antihypertensive drug use increased, it took 15% of national health insurance drug expenditure. This study aimed to examine the pattern of antihypertensive drug prescription using National Health Insurance claims database and compare it with recommendations of Korea Hypertension Treatment Guidelines. Among the antihypertensive drugs, calcium channel blocker(64.4%) was most commonly prescribed class, and diuretics(44.6%), angiotensin II receptor blocker(33.3%), angiotensin converting enzyme inhibitor(11.7%) was followed. Approximately 81% of antihypertensives prescription were without cardiovascular or cerebrovascular disease, and among the comorbid conditions, diabetes(10.7%) was most common. calcium channel blocker(62.3%) was mostly prescribed class for hypertension with angina pectoris, angiotensin receptor blocker(45.3%) with myocardial infarction, diuretics(70.2%) and calcium channel blocker(49.5%) with congestive heart failure. For Hypertension with cerebrovascular disease, calcium channel blocker(68.0%) and angiotensin receptor blocker(43.3%) were prescribed mainly. When it comes to diabetes, calcium channel blocker(57.2%) was still mostly prescribed and angiotensin receptor blocker(45.9%) followed. But in hospitals and tertiary hospitals, angiotensin receptor blocker(65.7, 66.1%) was mostly prescribed for the patients with diabetes. For Hypertension with chronic renal disease, angiotensin receptor blocker(59.5%), calcium channel blocker(56.5%), diuretics(54.6%) were mainly used. Average number of classes per prescribing was $1.89{\pm}0.89$ class, average days per prescribing was $33{\pm}19$ day. Among the hypertension without comorbidity, 40.5% of prescription was monotherapy and 58.8% of polytherapy included diuretics. Among the outpatient prescriptions, calcium channel blocker was the most commonly used class, and the prescription pattern in clinic did not closely followed recommendations of Hypertension Treatment Guidelines.

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Seismic Behaviour of Exterior Joints in Post-Tensioned Flat Plate Systems (포스트 텐션 플랫 플레이트 외부 접합부의 내진 거동)

  • Han, Sang-Whan;Kee, Seong-Hoon;Kang, Tomas H.K.;Cho, Jong;Lee, Li-Hyung
    • Journal of the Korea Concrete Institute
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    • v.18 no.5 s.95
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    • pp.595-602
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    • 2006
  • An experimental study was conducted to investigate seismic behaviour of post-tensioned(PT) exterior slab-column connections used for the purpose to resist gravity loads only. For these, 2/3-scale, two PT post-tensioned exterior connections with two different tendon arrangement patterns and one conventional reinforced concrete(RC) exterior connection was tested under quasi-static, uni-directional reversed cyclic loading. During the lateral testing, gravity forces transferred to the column were kept constant to closely simulate a moment to shear ratio of a real building. One of the objectives of this study was to assess the necessity and/or the quantity of bottom bonded reinforcement needed to resist moment reversal which would occur under significant inelastic deformations of the adjacent lateral force resisting systems. The ACI 318 and 352 provisions for structural integrity were applied to provide the bottom reinforcement passing through the column for the specimens. Prior test results were also collected to conduct comparative studies for some design parameters such as the tendon arrangement pattern, the effect of post-tensioning forces and the use of bottom bonded reinforcement. Consequently, the impact of tendon arrangement on the seismic performance of the PT connection, that is lateral drift capacity and ductility, dissipated energy and failure mechanism, was considerable. Moreover, test results showed that the amount of bottom reinforcement specified by ACI 352. 1R-89 was sufficient for resisting positive moments arising from moment reversal under reversed cyclic loads. Shear strength of the tested specimens was more accurately predicted by the shear strength equation(ACI 318) considering the average compressive stress over the concrete($f_{pc}$) due to post-tensioning forces than that without considering $f_{pc}$.

Flexural Behavior of Reinforced Recycled Aggregate Concrete Beams (순환골재를 사용한 철근콘크리트 보의 휨거동 특성)

  • Song, Seon-Hwa;Choi, Ki-Sun;You, Young-Chan;Kim, Keung-Hwan;Yun, Hyun-Do
    • Journal of the Korea Concrete Institute
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    • v.21 no.4
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    • pp.431-439
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    • 2009
  • These days the amount of demolished concrete waste has been increasing due to reconstruction and redevelopment of aged buildings. So the use of recycled aggregates is recommended to solve environmental problems. Some investigations have been carried out to study the flexural behavior of reinforced concrete beams with recycled aggregates. But these have some limitation due to the use of low quality recycled aggregates and small-scale specimens in the laboratory. The purpose of this experimental study is to evaluate the flexural behavior of simply supported RC beams subjected to four-point monotonic loading and made with recycled aggregates. Seven full-scale RC beams were manufactured with different replacement level of recycled aggregates. The main parameters of the study are combination of aggregates. From the test results, the flexural behavior of the beam is described in terms of crack patterns and failure modes. And the flexural strength of RC beam with different types of recycled coarse aggregates and recycled fine aggregates is compared with the provision of KCI code.

Fractal Analysis of Peri-Implant Bone Mineral Density before and after Functional Loading on Implant (기능하중에 따른 임플란트 주변 골밀도의 변화에 대한 프렉탈 구조 분석)

  • Hong, Seong-Wan;Lee, Jae-In;Cho, Hye-Won
    • Journal of Dental Rehabilitation and Applied Science
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    • v.27 no.4
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    • pp.359-370
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    • 2011
  • To identify osseointegration of implants, dentists were performed the radiographic analysis. The fractal analysis methods using periapical radiographs before and after loading on implants was to evaluate whether or not significant. 30 patients who were placed implants in dental hospital of Wonkwang university were participated in this study. Total of 42 implants were analyzed. And, 14 males and 16 females aged from 22 to 73 participated in this study. The two morphologic and Fractal analysis of the one trabecular patterns in alveolar bone were done using periapical views. Two periapical views, after implant placement, and after 2 months of functional loading were analysed. The analysis was done by software, Image J(1.40s, National Institute of Health, Bethesda, USA). The data were statistically analyzed using one-way ANOVA(P<.05). Multiple comparison was done by the Tukey HSD test. The results of Fractal analysis and change in bone density around implants showed significantly different values, especially mandibles. However, in case of implants with failure, Fractal values decreased from 1.2865 to 1.1521 and 1.1135 to 1.0478.

Comparison of Mechanical and Interfacial Properties on Chemical Structures of Acrylic and Epoxy Adhesives (아크릴 및 에폭시 접착제의 화학적 구조에 따른 유리섬유 복합재료의 기계적 및 계면 물성 변화 평가)

  • Shin, Pyeong-Su;Kim, Jong-Hyun;Choi, Jin-Yeong;Kwon, Dong-Jun;Lee, Sang-Il;Park, Joung-Man
    • Composites Research
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    • v.29 no.2
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    • pp.79-84
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    • 2016
  • An adhesive can be used to connect two different materials in structures. In comparing with other connecting methods, such as bolt, rivet, and hot melting, the adhesive does not need to use them. It leads to reduce the weight and decrease the stress concentration along the connecting line. This work studied the comparison of mechanical and interfacial properties of commonly-used two adhesives, acrylic type and bisphenol-A epoxy type. Tensile and flexural strength of neat adhesives were also compared. Lap shear test of two adhesives was deduced from the measurement of tensile and fatigue tests. After testing, the failure patterns of adhesive surfaces were observed by a microscope. Tensile strength and mechanical fatigue resistance at using bisphenol-A epoxy adhesive were better than acrylic adhesive. Also adding CNT reinforcement in epoxy adhesive can anticipate mechanical improvement.

Manufacturing and Mechanical Properties of Epoxy Fibers Spinning using Anhydride and Amine Hardeners (산 무수물계 및 아민계 경화제를 이용한 열경화성 에폭시 섬유 제조 및 물성)

  • Shin, Pyeong-Su;Kim, Jong-Hyun;Park, Ha-Seung;Baek, Yeong-Min;Kwon, Dong-Jun;Park, Joung-Man
    • Composites Research
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    • v.29 no.6
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    • pp.408-413
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    • 2016
  • Commonly-used polymers are manufactured as versatile forms. Furthermore, continuous polymer fibers are recently manufactured using nylon or aramid fiber. One of common epoxy was also used to make polymer fibers. Bisphenol-A type was used as base epoxy whereas amine and anhydride were used as hardeners. Epoxy fibers was cured by stepping up the temperature to maintain the shape of epoxy fiber. Surface energy was measured to confirm the degree of interfacial adhesion by modified static contact angle method. After mechanical properties were measured via fiber tensile test, the evaluation of fiber fracture was proceeded. Tensile strength of epoxy fiber using amine type hardener was higher as 138 MPa than anhydride case as 70 MPa. Fractured surface exhibited different failure patterns at the cross-section.

Thermo-mechanical Behavior of WB-PBGA Packages with Pb-Sn Solder and Lead-free Solder Using Moire Interferometry (무아레 간섭계를 이용한 유연 솔더와 무연 솔더 실장 WB-PBGA 패키지의 열-기계적 변형 거동)

  • Lee, Bong-Hee;Kim, Man-Ki;Joo, Jin-Won
    • Journal of the Microelectronics and Packaging Society
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    • v.17 no.3
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    • pp.17-26
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    • 2010
  • Pb-Sn solder is rapidly being replaced by lead-free solder for board-level interconnection in microelectronic package assemblies due to the environmental protection requirement. There is a general lack of mechanical reliability information available on the lead-free solder. In this study, thermo-mechanical behaviors of wire-bond plastic ball grid array (WB-PBGA) package assemblies are characterized by high-sensitivity moire interferometry. Experiments are conducted for two types of WB-PBGA packages that have Pb-Sn solder and lead-free solder as joint interconnections. Using real-time moire setup, fringe patterns are recorded and analyzed for several temperatures. Bending deformations of the assemblies and average strains of the solder balls are investigated and compared for the two type of WB-PBGA package assemblies. Results show that shear strain in #3 solder ball located near the chip shadow boundary is dominant for the failure of the package with Pb-Sn solder, while normal strain in #7 most outer solder ball is dominant for that with lead-free solder. It is also shown that the package with lead-free solder has much larger bending deformation and 10% larger maximum effective strain than the package with Pb-Sn solder at same temperature level.

An Optimum Slanting Angle in Reticulated Root Piles Installation under Compressive and Uplift Loads (압축 및 인발하중을 받는 그물식 뿌리말뚝의 최적 타설경사각)

  • 이승현;김명보
    • Geotechnical Engineering
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    • v.12 no.2
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    • pp.71-84
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    • 1996
  • In order to investigate the influence of slanting angle of reticulated root piles(RRP) on their bearing capacities, model tests of compressive and uplift loads on RRP with different slanting angles, which were installed in sandy soils with a relative density of 47%, were carried out. Each pile which is made of a steel bar of 5mm in diameter and 300mm in length, is coated with sand to be 6.5mm in diameter. One set of RRP consists of 8 piles which are installed in circular patterns forming two concentric circles, each of which has 4 piles. Slanting angles of RRP for load tests are 0$^{\circ}$, 5$^{\circ}$, 10$^{\circ}$, 15$^{\circ}$, 20$^{\circ}$, and 25$^{\circ}$. In addition, compressive load tests on circular footing whose diameter is the same as the outer circle of RRP were carried out. Test results show that maximum load bearing capacities of RRP by regression analysis are obtained at about 12$^{\circ}$ and 13$^{\circ}$ of slanting angles for compressive and uplift load tests, respectively. Maximum compressive bearing capacity is estimated to be 13oA bigger than that of the vertical RRP and 95% bigger than that of surface footing. Maximum uplift capacity is estimated to be 21% bigger than that of the vertical RRP. And it can be appreciated that increasing the slanting angle makes the load -Settlement behavior more ductile.

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COMPARISON OF SHEAR BOND STRENGTH AND MARGINAL LEAKAGE OF RESIN MODIFIED GLASS IONOMER CEMENTS (강화형 글라스 아이오노머 합착용 시멘트의 접합강도 및 변연누출에 대한 연구)

  • Park, Hye-Yang;Oh, Nam-Sik;Lee, Keun-Woo;Lee, Ho-Yong
    • The Journal of Korean Academy of Prosthodontics
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    • v.35 no.4
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    • pp.647-661
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    • 1997
  • The resin modified glass ionomer cements(RMGICs) have been used for years since 1989. Recently it has been developed for luting of fixed restorations. To evaluate the bond strength and marginal leakage of RMGICs for luting usage, the 80 extracted human molars which had uniform area of exposed dentin were cemented with 3 types of RMGICs(Fuji Duet, Advance, Vitremer), a conventional Glass Ionomer Cement(GIC-Fuji I), and a resin cement (Panavia 21) to base metal alloy(Ni-Cr-Be). After thermocycling the specimens were immersed in basic fuschin dye for measuring marginal leakage. The shear bond strength was measured with Instron and the maximum dye penetration was measured to 0.1mm. The types of fractured patterns were determined with stereoscope(${\times}7.5$). The results are as follows. 1. The difference between 3 RMGICs and a conventional GIC in shear bond strength was not statistically significant. It seemed that RMGICs had lower shear bond strength than resin cement. (p<0.01) 2. The mean scores of marginal leakage had no significant difference between the resin cement and 3 RMGICs but it was much higher in conventional GIC than the RMGICs (p<0.05) 3. It was determined that the manufacturer and the methods of dentin pretreatment determined the pattern of fracture surfaces and the frequency of adhesive failure between teeth and 3 RMGICs standed as in following order - Vitremer, Advance, Fuji Duet. (p<0. 01) When the fracture pattern was analyzed, it could be said that the materials and the method of dentin pretreatment have much effect on bonding states. This means that the dentin bonding agents should be improved. But the limited products in this experiment can not evaluate the physical properties of the entire RMGICs. Therefore a further study which can evaluate various RMGICs should be in progress to develope better cements.

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