• Title/Summary/Keyword: rejection

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Pediatric heart transplantation: how to manage problems affecting long-term outcomes?

  • Kim, Young Hwue
    • Clinical and Experimental Pediatrics
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    • v.64 no.2
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    • pp.49-59
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    • 2021
  • Since the initial International Society of Heart Lung Transplantation registry was published in 1982, the number of pediatric heart transplantations has increased markedly, reaching a steady state of 500-550 transplantation annually and occupying up to 10% of total heart transplantations. Heart transplantation is considered an established therapeutic option for patients with end-stage heart disease. The long-term outcomes of pediatric heart transplantations were comparable to those of adults. Issues affecting long-term outcomes include acute cellular rejection, antibody-mediated rejection, cardiac allograft vasculopathy, infection, prolonged renal dysfunction, and malignancies such as posttransplant lymphoproliferative disorder. This article focuses on medical issues before pediatric heart transplantation, according to the Korean Network of Organ Sharing registry and as well as major problems such as graft rejection and cardiac allograft vasculopathy. To reduce graft failure rate and improve long-term outcomes, meticulous monitoring for rejection and medication compliance are also important, especially in adolescents.

Performance prediction of flat sheet commercial nanofiltration membrane using Donnan-Steric Pore Model

  • Qadir, Danial;Nasir, Rizwan;Mukhtar, Hilmi;Uddin, Fahim
    • Membrane and Water Treatment
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    • v.12 no.2
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    • pp.59-64
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    • 2021
  • The rejection of sodium chloride (NaCl) and calcium chloride (CaCl2) single salt solutions were carried out for commercial nanofiltration NFDK membrane. Results showed that the NFDK membrane had a negative surface charge and had a higher observed rejection of 93.65% for calcium (Ca2+) ion and 78.27% for sodium (Na+) ions. Prediction of rejection for aqueous solutions of both salts was made using Donnan Steric Pore Model based on Extended Nernst-Planck Equation in addition to concentration polarization film theory. A MATLAB program was developed to execute the model calculations. Absolute Average Relative Error (% AARE) was found below 5% for real rejection of the NFDK membrane. This research could be used successfully to assess the membrane characterization parameter using a proposed procedure which can reduce the number of experiments.

Fuzzy Neural Network Active Disturbance Rejection Control for Two-Wheeled Self-Balanced Robot

  • Wang, Chao;Jianliang, Xiao;Zhang, Cheng
    • Journal of Information Processing Systems
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    • v.18 no.4
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    • pp.510-523
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    • 2022
  • Considering the problems of poor control effect, weak disturbance rejection ability and adaptive ability of two-wheeled self-balanced robot (TWSBR) systems on undulating roads, this paper proposes a fuzzy neural network active disturbance rejection controller (FNNADRC), that is based on fuzzy neural network (FNN) for online correction of active disturbance rejection controller (ADRC)'s nonlinear control rate. Firstly, the dynamic model of the TWSBR is established and decoupled, the extended state observer (ESO) is used to compensate dynamically and linearize the upright and displacement subsystems. Then, the nonlinear PD control rate and FNN are designed, and the FNN is used to modify the control parameters of the nonlinear PD control rate in real time. Finally, the proposed control strategy is simulated and compared with the traditional ADRC and fuzzy active disturbance rejection controller (FADRC). The simulation results show that the control effect of the proposed control strategy is slightly better than ADRC and FADRC.

The Influences of Covert Narcissism on Displaced Aggression in Late Childhood: The Mediating Effects of Internalized Shame and Rejection Sensitivity (학령후기 아동의 내현적 자기애가 전위 공격성에 미치는 영향: 내면화된 수치심과 거부민감성의 매개효과)

  • Lim, Hye Eun;Han, Sae-Young
    • Korean Journal of Child Studies
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    • v.37 no.4
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    • pp.129-143
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    • 2016
  • Objective: This study aimed to examine the mediating effects of internalized shame and rejection sensitivity in the relationship between covert narcissism and displaced aggression in late childhood. Methods: The participants included 1,060 children (grades 5 and 6; 547 boys and 513 girls) from four elementary schools located in Seoul, Gyeonggi-do, and Chungcheong-do. Results: The primary results of this study were as follows. First, child covert narcissism had a direct effect on displaced aggression; children who perceived higher levels of covert narcissism exhibited more displaced aggression. Second, child covert narcissism had an indirect effect on their displaced aggression through internalized shame and rejection sensitivity. Children who perceived higher levels of covert narcissism reported more internalized shame and rejection sensitivity, which led to more displaced aggression. Conclusion: The findings of this research indicate that individual and interpersonal psychological factors need to be considered to explain displaced child aggression. Further, it is important that we help children to gain positive relationships with family and peers. It will help them break away their negative self or others representation, especially their internalized shame and rejection sensitivity.

A Fast and Precise Blind I/Q Mismatch Compensation for Image Rejection in Direct-Conversion Receiver

  • Kim, Suna;Yoon, Dae-Young;Park, Hyung Chul;Yoon, Giwan;Lee, Sang-Gug
    • ETRI Journal
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    • v.36 no.1
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    • pp.12-21
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    • 2014
  • In this paper, we propose a new digital blind in-phase/quadrature-phase (I/Q) mismatch compensation technique for image rejection in a direct-conversion receiver (DCR). The proposed image-rejection circuit adopts DC offset cancellation and a sign-sign least mean squares (LMS) algorithm with a unique step size adaptation both for a fast and precise I/Q mismatch estimation. In addition, several performance-optimizing design considerations related to accuracy, speed, and hardware simplicity are discussed. The implementation of the proposed circuit in an FPGA results in an image-rejection ratio (IRR) of 65 dB, which is the best performance with modulated signals, along with an adaptation time of 0.9 seconds, which is a tenfold increase in the compensation speed as compared to previously reported circuits. The proposed technique will be a promising solution in the area of image rejection to increase both the speed and accuracy of future DCRs.

Measuring the Mediating Effects of Nausea and Learned Food Aversion on Relationships Linking Food Neophobia to Appetite and Food Rejection (식욕과 음식거절에 미치는 음식 신공포증의 영향을 위 불쾌감과 학습된 음식 거부가 매개하는지에 대한 효과 평가)

  • Kang, Jong-Heon;Ko, Beom-Seok
    • Korean Journal of Human Ecology
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    • v.16 no.1
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    • pp.183-191
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    • 2007
  • The purpose of this study was to measure the effect of nausea and learned food aversion on relationships linking food neophobia to appetite and food rejection. A total of 250 questionnaires were completed. Path analytic model was used measure the effect of mediator. Results of the study demonstrated that the path analytic result for the data also indicated excellent model fit. The influences of food neophobia on nausea and food rejection were statistically significant. The influences of nausea on learned food aversion and appetite were statistically significant. The influences of food neophobia on learned food aversion and appetite were not statistically significant. The influence of nausea on food rejection was not statistically significant. Moreover, nausea and aversion played a perfectly mediating roles in the relationship between food neophobia and appetite. Aversion also played no mediating role in the relationship between food neophobia and food rejection.

Effects of hypochlorite exposure on morphology and trace organic contaminant rejection by NF/RO membranes

  • Simon, Alexander;Nghiem, Long D.
    • Membrane and Water Treatment
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    • v.5 no.4
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    • pp.235-250
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    • 2014
  • The impacts of membrane degradation due to chlorine attack on the rejection of inorganic salts and trace organic contaminants by nanofiltration (NF) and reverse osmosis (RO) membranes were investigated in this study. The rejection of trace contaminants was examined at environmentally relevant concentrations. Changes in the membrane surface morphology were observed as a result of chlorine exposure. A small increase in rejection was consistently observed with all four membranes selected in this study after being exposed to a low concentration of hypochlorite (100 ppm). In contrast, a higher concentration of hypochlorite (i.e., 2000 ppm) could be detrimental to the membrane separation capacity. Membranes with severe chlorine impact showed a considerable decrease in rejection over filtration time, possibly due to rearrangement of the polyamide chains under the influence of chlorine degradation and filtration pressure. The reported results indicate that loose NF membranes are more sensitive to chlorine exposure than RO membranes. The impact of hypochlorite exposure (both positive and negative) on rejection is dependent on the strength of the hypochlorite solution and is more significant for the neutral carbamazepine compound than the negatively charged sulfamethoxazole.

Acute Rejection after Renal Allograft in a Dog (개의 신장 동종이식 후 발생된 급성 거부반응)

  • Nam Hyun sook;Uhm Ji Yong;Yoon Byung IL;Woo Heung Myung
    • Journal of Veterinary Clinics
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    • v.22 no.4
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    • pp.439-443
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    • 2005
  • Rejection is one of the life-threatening complications after organ transplantation. An eight-month-old, intact male, mixed breed dog was presented with acute rejection after renal allograft. The heterotopic renal transplantation with bilateral nephrectomy was performed in the dog. The triple drug protocol for immunosuppression was applied for prevention of the acute rejection. Postoperative care was done according to the transplantation protocol of VMTH, Kangwon National University. The dog was euthanized when the serum creatinine concentration exceeded 5 mg/dL followed by tile signs of illness. The transplanted kidney was enlarged. The renal cortex lesions were characterized by necrosis of the renal tubules and the glomeruli. Interstitial lesions were characterized by hemorrhage and severe infiltration of lymphoid cells. Intrarenal arteries showed necrosis of the walls and infiltration of perivascular lymphoid cells. In immunohistochemical (IHC) findings, infiltration of the CD4 and the CD8 positive T lymphocytes was examined. In this case, acute rejection was shown by humoral and cellular immunity on the basis of histopathologic and IHC evaluation.

Rejection Properties of Aromatic Pesticides by a Hollow Fiber NF Membrane (중공사 나노여과막을 이용한 방향족 농약의 배제 특성)

  • Jung, Yong-Jun;Kiso, Yoshiaki;Park, Soon-Gil;Kim, Jong-Yong;Min, Kyung-Sok
    • Journal of Korean Society on Water Environment
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    • v.20 no.3
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    • pp.296-300
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    • 2004
  • The rejection properties of 6 aromatic pesticides were evaluated by a continuous flow system equipped with a hollow fiber NF membrane. Different from the separation experiment of batch cell, the rejection and the removal could be calculated exactly because the concentration of feed, permeate and retentate was separately obtained. The lowest and the highest rejection were found in carbaryl(54.8%) and methoxychlor(99.2%), respectively, and the removals were always shown higher than rejections. This may be caused by some reasons such as the solute adsorption on the membrane, the variation of feed concentration. Although molecular weight, molecular width regarded as solute characteristics and log P(n-octanol/water partition coefficient) as hydrophobicity could be applied to explain the rejection property, these factors should be considered together for better analysis. According to the higher relationship between log B(solute permeability) and molecular weight, it was revealed that the solute separation with this membrane was influenced more by molecular weight.

The Effect of Socially Prescribed Perfectionism in Upper Elementary School Students on Their Interpersonal Anxiety: The Sequential Mediating Effect of Dichotomous Thinking and Rejection Sensitivity (초등학교 고학년 아동의 사회부과 완벽주의가 대인불안에 미치는 영향: 이분법적 사고와 거부민감성의 순차적 매개효과)

  • Youngseo Kang;Ju Hee Park
    • Human Ecology Research
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    • v.62 no.1
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    • pp.165-179
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    • 2024
  • This study examined the effects of perceived discrimination on multicultural adolescents regarding feelings of This study examined the direct effect of socially prescribed perfectionism on interpersonal anxiety in upper elementary school students and the sequential mediating effect of dichotomous thinking and rejection sensitivity on this relationship. The sample comprised 306 upper elementary school students (grades 4 to 6; 149 boys, 48.7%) in Seoul, Incheon, and Busan. The Data were collected through an online self-report questionnaire completed by the participants and analyzed using SPSS version 27.0 and MPlus version 8.7 software. The analyses revealed three key findings. First the direct effect of socially prescribed perfectionism on interpersonal anxiety was not statistically significant. Second dichotomous thinking mediated the relationship between socially prescribed perfectionism and interpersonal anxiety, whereas rejection sensitivity did not. Finally, socially prescribed perfectionism influenced interpersonal anxiety through the sequential mediation of dichotomous thinking and rejection sensitivity. In conclusion, although socially prescribed perfectionism does not directly influence interpersonal anxiety, children may experience interpersonal anxiety in situations involving dichotomous thinking due to socially prescribed perfectionism, leading to rejection sensitivity. These findings suggest that interventions for interpersonal anxiety in upper elementary school students should focus on psychological problems attributed to socially prescribed perfectionism.