• 제목/요약/키워드: Post Modification

검색결과 336건 처리시간 0.032초

Crystallinity of Low Molar Ratio Urea-Formaldehyde Resins Modified with Cellulose Nanomaterials

  • PARK, Seongsu;PARK, Byung-Dae
    • Journal of the Korean Wood Science and Technology
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    • 제49권2호
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    • pp.169-180
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    • 2021
  • Inherent crystalline domains present in low formaldehyde to urea (F/U) molar ratio urea-formaldehyde (UF) resins are responsible for their poor adhesion in wood-based composite panels. To modify the crystallinity of low molar ratio (LMR) UF resins, this study investigates the additional effect of cellulose nanomaterials (CNMs), such as cellulose microfibrils (CMFs), cellulose nanofibrils (CNFs), and TEMPO-oxidized CNFs (TEMPO-CNFs) on the crystallinity of modified LMR UF resins. First, two modification methods (post-mixing and in situ) were compared for modified LMR UF resins with TEMPO-CNFs. The modified UF resins with TEMPO-CNFs decreased the nonvolatile solid contents, while increasing the viscosity and gel time. However, the in situ modification of UF resins with TEMPO-CNFs showed lower crystallinity than that of post-mixing. Then, the in situ method was compared for all CNMs to modify LMR UF resins. The modified UF resins with CMFs using the in situ method increased nonvolatile solid contents and viscosity but decreased the gel time. The crystallinity of UF resins modified with TEMPO-CNFs was the lowest even though the crystalline domains were not significantly changed for all modified UF resins. These results suggest that these CNMs should be modified to prevent the formation of crystalline domains in LMR UF resins.

Development of a Health Education Modification Program Regarding Liver Flukes and Cholangiocarcinoma in High Risk Areas of Nakhon Ratchasima Province Using Self-Efficacy and Motivation Theory

  • Kaewpitoon, Soraya J;Rujirakul, Ratana;Wakkuwattapong, Parichart;Benjaoran, Fuangfa;Norkaew, Jun;Kujapun, Jirawoot;Ponphimai, Sukanya;Chavenkun, Wasugree;Kompor, Porntip;Padchasuwan, Natnapa;Kaewpitoon, Natthawut
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권6호
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    • pp.2947-2951
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    • 2016
  • A quasi-experimental study was conducted to develop a health education modification program based on self-efficacy and motivation regarding liver flukes and cholangiocarcinoma development in Keang Sanam Nang district, Nakhon Ratchasima province, Thailand. A total of 36 individuals were invited to participate in the program and were screened for population at risk of liver fluke infection and cholangiocarcinoma using SUT-OV-001 and SUT-CCA-001. Development of health education modification program regarding liver fluke and cholangiocarcinoma prevention included 3 steps: (1) preparation, (2) health education program, and (3) follow-up and evaluation. The study was implemented for 10 weeks. Pre-and-post-test knowledge was measured with questionnaires, Kuder-Richardson-20: KR-20 = 0.718,and Cronbach's Alpha Coefficient = 0.724 and 0.716 for percection and outcome expectation questionnaires. Paired and independent t-tests were applied for data analysis. The majority of the participants were female (55.6%), aged between ${\leq}50$ and 60 years old (36.1%), married (86.1%), education level of primary school (63.9%), agricultural occupation (80.6%), and income <4,000 Baht (44.4%). The results revealed that after the health education program, the experimental group had a mean score of knowledge, perception, and outcome expectation regarding liver fluke and cholangiocarcinoma prevention significantly higher than before participation and in the control group. In conclusion, this successful health education modification program for liver fluke and cholangiocarcinoma, therefore may useful for further work behavior modification in other epidemic areas.

Assessment of Recanalization after Intra-Arterial Thrombolysis in Patients with Acute Ischemic Stroke : Proposed Modification of the Qureshi Grading System

  • Kim, Jae-Hoon;Kang, Hee-In;Moon, Byung-Gwan;Lee, Seung-Jin;Kim, Joo-Seung
    • Journal of Korean Neurosurgical Society
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    • 제51권5호
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    • pp.262-267
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    • 2012
  • Objective : We aimed to investigate the correlation between the success of recanalization and a modified version of the Qureshi grading system in acute ischemic stroke patients. Methods : We retrospectively analyzed the intra-arterial thrombolysis (IAT) records of 37 patients who were evaluated by Thrombolysis in Myocardial Infarction (TIMI) and a modified version of the Qureshi grading systems as follows : 1) post-IAT Qureshi grade, 2) modified ${\Delta}$ Qureshi grade : pre-IAT group grade - post-IAT group grade (grade 1 : Qureshi grades 0-2 and grade 2 : Qureshi grade 3-5) and 3) ${\Delta}$ Qureshi grade (post-IAT Qureshi grade - pre-IAT Qureshi grade). Successful recanalization was defined as follows : 1) post-IAT TIMI grades 2 and 3, 2) post-IAT Qureshi grade 0-2, 3) modified ${\Delta}$ Qureshi grade=1, and 4) ${\Delta}$ Qureshi grade of ${\geq}2$ and/or post-IAT Qureshi grade=0. We investigated the correlation between the post-IAT TIMI grade and the modified Qureshi grade and also compared the various grading systems with modified Rankin Scale scores for evaluating the clinical outcome at 3 months. Results : The post-IAT Qureshi grade and ${\Delta}$ Qureshi grade and/or post-IAT Qureshi grade were significantly correlated with the TIMI grade (${\gamma}$=0.976 and, 0.942, respectively). Further, post-IAT Qureshi grade and ${\Delta}$ Qureshi grade and/or post-IAT Qureshi grade showed a significantly stronger association with clinical outcome than did the post-IAT TIMI grade (p=0.001 and, 0.000 vs. 0.083, respectively). Conclusion : Our preliminary results suggest that the modified Qureshi grading system is a useful tool for assessing the success of recanalization after IAT.

후처리기에 의한 3축 수평머시닝센터의 체적오차보정 (Volumetric Error Compensation of a 3-Axis Horizontal Machining Center in the Post-processor)

  • 양승한;권성환
    • 한국생산제조학회지
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    • 제8권3호
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    • pp.28-34
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    • 1999
  • The objective of this study is to estimate and to compensate far the volumetric error of a workpiece influenced by the geometric error of a machine tool. In this paper, the volumetric error is defined and the error synthesis model is presented. Then, the volumetric error of workpiece is calculated and compared through the simulation, and a new tool-path is generated to compensate for the error in the post-processor of CAM system using the error synthesis model. By this method, the error is compensated without modification or replacement of a machine tool being in use.

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Influence of modification in core building procedure on fracture strength and failure patterns of premolars restored with fiber post and composite core

  • Kim, Young-Hoi;Lee, Jong-Hyuk
    • The Journal of Advanced Prosthodontics
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    • 제4권1호
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    • pp.37-42
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    • 2012
  • PURPOSE. The influence of the modified process in the fiber-reinforced post and resin core foundation treatment on the fracture resistance and failure pattern of premolar was tested in this study. MATERIALS AND METHODS. Thirty-six human mandibular premolars were divided into 4 groups (n = 9). In group DCT, the quartz fibre post (D.T. Light-post) was cemented with resin cement (DUO-LINK) and a core foundation was formed with composite resin (LIGHT-CORE). In group DMO and DMT, resin cement (DUO-LINK) was used for post (D.T. Lightpost) cementation and core foundation; in group DMO, these procedures were performed simultaneously in one step, while DMT group was accomplished in separated two steps. In group LCT, the glass fiber post (LuxaPost) cementation and core foundation was accomplished with composite resin (LuxaCore-Dual) in separated procedures. Tooth were prepared with 2 mm ferrule and restored with nickel-chromium crowns. A static loading test was carried out and loads were applied to the buccal surface of the buccal cusp at a 45 degree inclination to the long axis of the tooth until failure occurred. The data were analyzed with MANOVA (${\alpha}$= .05). The failure pattern was observed and classified as either favorable (allowing repair) or unfavorable (not allowing repair). RESULTS. The mean fracture strength was highest in group DCT followed in descending order by groups DMO, DMT, and LCT. However, there were no significant differences in fracture strength between the groups. A higher prevalence of favorable fractures was detected in group DMT but there were no significant differences between the groups. CONCLUSION. The change of post or core foundation method does not appear to influence the fracture strength and failure patterns.

후열처리 및 seeding 층이 초음파분무 MOCVD법에 의한 PLT 박막 제조 시 전기적 특성에 미치는 영향 (Effects of post-annealing and seeding layers on electrical properties of PLT thin films by MOCVD using ultrasonic spraying)

  • 이진홍;김기현;박병옥
    • 한국결정성장학회지
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    • 제12권5호
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    • pp.247-252
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    • 2002
  • $(Pb_{1-x}La_x)TiO_3$ (x = 0.1) 박막을 초음파분무 MOCVD법으로 ITO-coated glass 기판 위에 제조하였다. PLT 박막 제조 시 후열처리 및 seeding layer가 결정화 및 미세구조, 전기적 특성에 대한 영향을 알아보았다. 후열처리에 의하여 박막의 결정성은 향상되었고 미세구조에도 영향을 주었으며, 전기적 특성은 이들 특성의 변화에 의해서 향상되었다. 그리고 seeding layer에 의한 핵 생성자리 제공에 의하여 결정성의 향상과 grain 크기의 증가에 의하여 박막의 전기적 특성 또한 향상되었다. Seeding layer를 가지고 60분 동안 후열처리를 한 박막이 가장 우수한 전기적 특성을 나타내었으며 이 박막의 1 kHz에서 유전 상수는 213을 나타내었다.

A New Insight into the Role of Calpains in Post-mortem Meat Tenderization in Domestic Animals: A review

  • Lian, Ting;Wang, Linjie;Liu, Yiping
    • Asian-Australasian Journal of Animal Sciences
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    • 제26권3호
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    • pp.443-454
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    • 2013
  • Tenderness is the most important meat quality trait, which is determined by intracellular environment and extracellular matrix. Particularly, specific protein degradation and protein modification can disrupt the architecture and integrity of muscle cells so that improves the meat tenderness. Endogenous proteolytic systems are responsible for modifying proteinases as well as the meat tenderization. Abundant evidence has testified that calpains (CAPNs) including calpain I (CAPN1) and calpastatin (CAST) have the closest relationship with tenderness in livestock. They are involved in a wide range of physiological processes including muscle growth and differentiation, pathological conditions and post-mortem meat aging. Whereas, Calpain3 (CAPN3) has been established as an important activating enzyme specifically expressed in livestock's skeletal muscle, but its role in domestic animals meat tenderization remains controversial. In this review, we summarize the role of CAPN1, calpain II (CAPN2) and CAST in post-mortem meat tenderization, and analyse the relationship between CAPN3 and tenderness in domestic animals. Besides, the possible mechanism affecting post-mortem meat aging and improving meat tenderization, and current possible causes responsible for divergence (whether CAPN3 contributes to animal meat tenderization or not) are inferred. Only the possible mechanism of CAPN3 in meat tenderization has been confirmed, while its exact role still needs to be studied further.

단백질 분해가 식물의 진균 병 진전에 미치는 영향 (The Roles of Protein Degradation During Fungal-plant Interactions)

  • 안일평;박상렬;배신철
    • 한국균학회지
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    • 제38권2호
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    • pp.89-94
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    • 2010
  • 농업경영측면에서, 또 균학적생화학적 측면에서도 식물을 침해하는 진균들의 연구는 반드시 필요하며 병 발생이나 저항성 발현 기작 구명은 기주와 기생체에 대한 연구를 동시에 진행해야 정확히 파악할 수 있다. 현재 병원균이 생산하는 분비체상과 비병원성 인자에 대한 연구는 많은 경우 세균에서 수행되고 있으며 사상균 중 조균인 Phytophthora와 진균인 Cladosporium에서만 병원균의 effector 복합체와 기주의 저항성 기제 간 관계가 같이 진행되고 있을 뿐이다. 앞에서 살펴보았듯 진균-기주 체계에서 단백질 분해가 병원성 조절 및 침입에 관여한다고 정확히 알려진 것은 단지 수종에 불과하며 그 기작도 세포자가포식과 ubiquitin 부가반응에 제한되어 있다. Post translational modification과 단백질 분해기작이 대단히 다양하고 거의 모든 진핵생물 체계에서 관찰되고 있음을 고려할 때 단백질 분해 과정은 세균 뿐 아니라 진균에서도 병원성 발현과 저항성 조절에 참여하고 있을 것으로 생각되며 이에 대한 연구가 앞으로 계속 요구될 것이라 생각된다.

SARS-CoV-2 Infection Induces HMGB1 Secretion Through Post-Translational Modification and PANoptosis

  • Man Sup Kwak;Seoyeon Choi;Jiseon Kim;Hoojung Lee;In Ho Park;Jooyeon Oh;Duong Ngoc Mai;Nam-Hyuk Cho;Ki Taek Nam;Jeon-Soo Shin
    • IMMUNE NETWORK
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    • 제23권3호
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    • pp.25.1-25.17
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    • 2023
  • Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection induces excessive pro-inflammatory cytokine release and cell death, leading to organ damage and mortality. High-mobility group box 1 (HMGB1) is one of the damage-associated molecular patterns that can be secreted by pro-inflammatory stimuli, including viral infections, and its excessive secretion levels are related to a variety of inflammatory diseases. Here, the aim of the study was to show that SARS-CoV-2 infection induced HMGB1 secretion via active and passive release. Active HMGB1 secretion was mediated by post-translational modifications, such as acetylation, phosphorylation, and oxidation in HEK293E/ACE2-C-GFP and Calu-3 cells during SARS-CoV-2 infection. Passive release of HMGB1 has been linked to various types of cell death; however, we demonstrated for the first time that PANoptosis, which integrates other cell death pathways, including pyroptosis, apoptosis, and necroptosis, is related to passive HMGB1 release during SARS-CoV-2 infection. In addition, cytoplasmic translocation and extracellular secretion or release of HMGB1 were confirmed via immunohistochemistry and immunofluorescence in the lung tissues of humans and angiotensin-converting enzyme 2-overexpressing mice infected with SARS-CoV-2.

Host Cell Nuclear Localization of Shigella flexneri Effector OspF Is Facilitated by SUMOylation

  • Jo, Kyungmin;Kim, Eun Jin;Yu, Hyun Jin;Yun, Cheol-Heui;Kim, Dong Wook
    • Journal of Microbiology and Biotechnology
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    • 제27권3호
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    • pp.610-615
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    • 2017
  • When Shigella infect host cells, various effecter molecules are delivered into the cytoplasm of the host cell through the type III secretion system (TTSS) to facilitate their invasion process and control the host immune responses. Among these effectors, the S. flexneri effector OspF dephosphorylates mitogen-activated protein kinases and translocates itself to the nucleus, thus preventing histone H3 modification to regulate expression of proinflammatory cytokines. Despite the critical role of OspF, the mechanism by which it localizes in the nucleus has remained to be elucidated. In the present study, we identified a potential small ubiquitin-related modifier (SUMO) modification site within OspF and we demonstrated that Shigella TTSS effector OspF is conjugated with SUMO in the host cell and this modification mediates the nuclear translocation of OspF. Our results show a bacterial virulence factor can exploit host post-translational machinery to execute its intracellular trafficking.