• Title/Summary/Keyword: persistent

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Diagnosis of Persistent Right Aortic Arch with an Aberrant Left Subclavian Artery using CT in a Poodle Dog

  • Ryu, Chan-Young;Lee, Sang-Gwan;Lee, Kija
    • Journal of Veterinary Clinics
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    • v.35 no.1
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    • pp.26-29
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    • 2018
  • A 6-month-old, female poodle presented with a three-month history of persistent regurgitation immediately after eating. On physical examination, the patient was emaciated and dehydrated. Thoracic radiography showed ventral displacement of the trachea and increased radiopacity in the mediastinum, cranial to the heart base. A severely dilated esophagus was identified cranial to the heart on esophagram. Computed tomography (CT) revealed the esophagus was filled with gas, fluid and a little of contrast and dilated from caudo-cervical to cranio-thoracic part. The esophageal diameter was markedly decreased at the heart base. In addition, the trachea was displaced to the left-ventral side of the right aortic trunk and an aberrant left subclavian artery originating from the aorta was identified. There was no evidence of abdominal vascular anomaly. Based on diagnostic imaging, persistent right aortic arch (PRAA) with an aberrant left subclavian artery was diagnosed. The patient did not undergo surgery and died at 15 days after diagnosis. This report describes imaging diagnosis, including CT and radiography in a weaned dog with regurgitation due to esophageal obstruction by PRAA. When PRAA is suspected and conventional radiography or contrast study is insufficient for diagnosis, CT may be helpful for diagnosing PRAA.

Anomalous Photoluminescence and Persistent Photoconductivity of AlxGal-xN/GaN Epilayers (AlxGal-xN/GaN 에피층의 비정상적인 광발광과 Persistent Photoconductivity 현상)

  • Chung, S.J.;Jun, Y.K.
    • Korean Journal of Materials Research
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    • v.13 no.10
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    • pp.673-676
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    • 2003
  • We have investigated $Al_{x}$ $Ga_{l-x}$ N/GaN epilayers (x = 0.08, 0.15) grown by metal organic vapor phase epitaxy on sapphire with photoluminescence(PL), and persistent photoconductivity(PPC) experiments. An anomalous S-shaped shift behavior of temperature dependencies of PL peak energy is observed for the x = 0.15 sample. In PPC measurement, showed that the dark current recovery time of $Al_{x}$$Ga_{l-x}$ N/GaN epilayers mainly depends on the Al content. These behaviors are usually attributed to the presence of carrier localization states. All these phenomena are explained based on the alloy compositional fluctuations in the $Al_{x}$ /$Ga_{l-x}$ N/ epilayers. The photocurrent quenching observed in PPC measurements for $Al_{x}$ $Ga_{l-x}$ N/ epilayers less than 0.2 $\mu\textrm{m}$ thickness indicates that the presence of metastable state in the bandgap of GaN layer, and that the excess holes in the valence band recombine with free electrons.

2018 심방세동 카테터 절제술 대한민국 진료지침: Part II

  • Yu, Hui-Tae;Jeong, Dong-Seop;Park, Hui-Nam;Park, Hyeong-Seop;Kim, Ju-Yeon;Kim, Jun;Lee, Jeong-Myeong;Kim, Gi-Hun;Yun, Nam-Sik;No, Seung-Yeong;O, Yong-Seok;Jo, Yeong-Jin;Shim, Jaemin
    • International Journal of Arrhythmia
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    • v.19 no.3
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    • pp.235-284
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    • 2018
  • In this part the writing group will cover strategies, techniques, and endpoints of atrial fibrillation (AF) ablation. Prior to all, electrical isolation of the pulmonary veins is recommended during all AF ablation procedures. In addition, techniques to be used for ablation of persistent and long-standing persistent AF, adjunctive ablation strategies, nonablative strategies to improve outcomes of AF ablation, and endpoints for ablation of paroxysmal, persistent, and long-standing persistent AF will be reviewed. Currently many technologies and tools are employed for AF ablation procedures. Radiofrequency energy, cryoablation, and other energy sources and tools are in various stages of development and/or clinical investigation. Finally, anticoagulation strategies pre-, during, and postcatheter ablation of AF and technical aspects of ablation to maximize safety are discussed in this section.

Characteristics Analysis of a Small Scale Persistent Current Switch System by using Coated Conductor (Coated Conductor를 이용한 소용량 영구전류스위치 시스템의 특성 해석)

  • Kim, Yeong-Sik;Yoon, Yong-Soo;Yang, Seong-Eun;Park, Dong-Keun;Ahn, Min-Cheol;Ko, Tae-Kuk
    • Progress in Superconductivity and Cryogenics
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    • v.9 no.1
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    • pp.47-52
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    • 2007
  • This paper presents characteristics analysis of persistent current switch(PCS) system on a small scale by using YBCO coated conductor(CC). A high temperature superconductor(HTS) PCS system mainly consists of a PCS, a HTS magnet load and a magnet power supply(MPS). To design the optimal heater triggering switch. the three-dimensional heat conduction model was analyzed by finite element method(FEM). The electrical equivalent model considering the n-value of CC was applied to analyze current decay during persistent current mode. In the experiment and simulation, the heater was applied with a current of 0.43A and the current was ramped up to 10A and 20A with 0.2A/s. Finally, experimental results of the HTS PCS system have been compared with the theoretical results. It has been concluded that flux creep can not influence the results because the operating current was 40% of critical current and optimal sequential operation of the PCS system is indispensable to enhance its performance.

Fabrication of a BSCCO Magnet and its Operating Characteristics of Current Compensation in Persistent Current Mode (BSCCO Magnet 제작 및 영구전류모드에서의 전류 보상 운전 특성)

  • Jo, Hyun-Chul;Chang, Ki-Sung;Jang, Jae-Young;Kim, Hyung-Jun;Chung, Yoon-Do;Yoon, Yong-Soo;Ko, Tae-Kuk
    • Progress in Superconductivity and Cryogenics
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    • v.12 no.1
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    • pp.56-60
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    • 2010
  • Recently, many researches have been carried out for a high temperature superconducting (HTS) magnet which is advantageous in high critical current density and critical temperature. In HTS magnet, however, critical current is decreased by perpendicular magnetic field and persistent current is hard to maintain due to a low index value and high joint resistance compared with low temperature superconducting (LTS) magnet. In this paper, the HTS magnet using BSCCO wire was simulated through finite element method (FEM) and manufactured. we experimentally investigated operating characteristics of the compensating mode of the HTS magnet for current decay and made a comparison between persistent current mode and compensating mode. A feedback control unit was used to sustain current within specified ranges with defined upper and lower limits.

A review of experimental and numerical studies on crack growth behaviour in rocks with pre-existing flaws

  • G. Sivakumar;V.B. Maji
    • Geomechanics and Engineering
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    • v.35 no.4
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    • pp.333-366
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    • 2023
  • Rock as a mass generally exhibits discontinuities, commonly witnessed in rock slopes and underground structures like tunnels, rock pillars etc. When these discontinuities experiences loading, a new crack emerges from them which later propagates to a macro scale level of failure. The failure pattern is often influenced by the nature of discontinuity, geometry and loading conditions. The study of crack growth in rocks, namely its initiation and propagation, plays an important role in defining the true strength of rock and corresponding failure patterns. Many researchers have considered the length of the discontinuity to be fully persistent on rock or rock-like specimens by both experimental and numerical methods. However, only during recent decades, there has been a substantial growth in research interest with non-persistent discontinuities where the crack growth and its propagation phenomenon were found to be much more complex than persistent ones. The non-persistence fractures surface is generally considered to be open and closed. Compared to open flaws, there is a difference in crack growth behaviour in closed or narrow flaws due to the effect of surface closure between them. The present paper reviews the literature that has contributed towards studying the crack growth behaviour and its failure characteristics on both open and narrow flaws subjected to uniaxial and biaxial compression loading conditions.

Procedural Quest Generation by NPC in MMORPG (MMORPG에서 NPC중심의 절차적 퀘스트 생성)

  • Jeong, Bo-Gyun;Cho, Sung Hyun;Kang, Shin Jin
    • Journal of Korea Game Society
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    • v.14 no.1
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    • pp.19-28
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    • 2014
  • This paper tried to verify whether we can make NPCs generate emergent quests consistently by experiments in the persistent world of Role Playing Games where the persistent world can generate stories through interaction among game components. In this paper, we test NPC based procedural quest generation techniques assuming quest types suggested in the past research in the persistent virtual RPG world. Our system uses desire model of NPCs and dynamic resource management system to make decision of quest generation. Our decision process considers desire satisfaction, money deposit, and friendship of NPCs. These parameters are dynamically changed by quest completion status, and affect next quest generation process. This paper shows that NPCs in the persistent virtual world can generate quests based on procedural quest techniques consistently.

CT Findings of Persistent Pure Ground Glass Opacity: Can We Predict the Invasiveness?

  • Liu, Li-Heng;Liu, Ming;Wei, Ran;Jin, Er-Hu;Liu, Yu-Hui;Xu, Liang;Li, Wen-Wu;Huang, Yong
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.5
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    • pp.1925-1928
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    • 2015
  • Background: To investigate whether CT findings can predict the invasiveness of persistent cancerous pure ground glass opacity (pGGO) by correlating the CT imaging features of persistent pGGO with pathological changes. Materials and Methods: Ninety five patients with persistent pGGOs were included. Three radiologists evaluated the morphologic features of these pGGOs at high resolution CT (HRCT). Binary logistic regression was used to assess the association between CT findings and histopathological classification (pre-invasive and invasive groups). Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic performance of diameters. Results: A total of 105 pGGOs were identified. Between pre-invasive (atypical adenomatous hyperplasia, AAH, and adenocarcinoma in situ, AIS) and invasive group (minimally invasive adenocarcinoma, MIA and invasive lung adenocarcinomas, ILA), there were significant differences in diameter, spiculation and vessel dilatation (p<0.05). No difference was found in air-bronchogram, bubble-lucency, lobulated-margin, pleural indentation or vascular convergence (p>0.05). The optimal threshold value of the diameters to predict the invasiveness of pGGO was 12.50mm. Conclusions: HRCT features can predict the invasiveness of persistent pGGO. The pGGO with a diameter more than 12.50mm, presences of spiculation and vessel dilatation are important factors to differentiate invasive adenocarcinoma from pre-invasive cancerous lesions.

A case of persistent pulmonary hypertension of the newborn: Treatment with inhaled iloprost (Iloprost 흡입 투여로 치료한 신생아 폐고혈압 지속증 1예)

  • Jang, Yoon Young;Park, Hye Jin
    • Clinical and Experimental Pediatrics
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    • v.52 no.10
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    • pp.1175-1180
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    • 2009
  • We report a case of a full-term neonate with persistent pulmonary hypertension who developed asphyxia after birth and was treated with iloprost. The neonate had persistent hypoxia and did not respond to supportive treatment. Because inhaled nitric oxide (iNO) was not available in our hospital, inhaled iloprost was administered via an endotracheal tube. This resulted in an immediate elevation of oxygen saturation. Echocardiography revealed the conversion of the right-to-left ductal shunt to the left-to-right one and a decrease of the right ventricular pressure. The use of inhaled iloprost did not cause any significant side effects. Here, we describe our experience where iloprost was used in a neonate with persistent pulmonary hypertension because the standard therapy with inhaled nitric oxide was not available.

Factors Associated with Persistent Sputum Positivity at the End of the Second Month of Tuberculosis Treatment in Lithuania

  • Diktanas, Saulius;Vasiliauskiene, Edita;Polubenko, Katazyna;Danila, Edvardas;Celedinaite, Indre;Boreikaite, Evelina;Misiunas, Kipras
    • Tuberculosis and Respiratory Diseases
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    • v.81 no.3
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    • pp.233-240
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    • 2018
  • Background: Non-conversion of sputum smear and culture prolongs the infectivity of the patient and has been associated with unfavorable outcomes. We aimed to evaluate factors associated with persistent sputum positivity at the end of two months of treatment of new case pulmonary tuberculosis (TB). Methods: Data of 87 human immunodeficiency virus-negative patients with culture-positive drug-susceptible pulmonary TB admitted to local university hospital between September 2015 and September 2016 were reviewed. Factors associated with sputum smear and/or culture positivity at the end of the second month of treatment were analyzed. Results: Twenty-two patients (25.3%) remained smear and/or culture-positive. Male sex, lower body mass index (BMI), unemployment, alcohol abuse, higher number of lobes involved and cavities on chest X-rays, shorter time to detection (TTD) on liquid cultures, higher respiratory sample smear grading and colony count in solid cultures, higher C-reactive protein, erythrocyte sedimentation rate, leukocytosis, thrombocytosis, and anemia were all significantly associated with persistent sputum positivity. However, in the logistic regression analysis only male sex, lower BMI, alcohol abuse, higher radiological involvement, cavitation, higher smear grading, higher colony count in solid cultures and shorter TTD were determined as independent factors associated with persistent sputum positivity at the end of 2 months of treatment. Conclusion: In conclusion, higher sputum smear and culture grading at diagnosis, shorter TTD, higher number of lobes involved, cavitation, male sex, alcohol abuse, and lower BMI were independently associated with persistent sputum positivity. These factors should be sought when distinguishing which patients will remain infectious longer and possibly have worse outcomes.