• Title/Summary/Keyword: Anti-attachment

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Sensitivity Analysis of Anti-resonance Frequency for Vibration Test Control of a Fixture

  • Jeong, Weui-Bong;Yoo, Wan-Suk;Kim, Jun-Yeop
    • Journal of Mechanical Science and Technology
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    • v.17 no.11
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    • pp.1732-1738
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    • 2003
  • The test specimen in environmental vibration test is connected to the fixture through several attachment points. The forces generated by the shaker must be transmitted equally to all attachment points. The forces transmitted to attachment points, however, are different because of the flexural vibration of the fixture. The variations of the transmitted force cause the under-test, especially at anti-resonance frequencies, in vibration test control. Anti-resonance frequencies at the attachment points of the fixture must be same in order to avoid the under-test in vibration test control. The structural modification of the fixture is needed so that anti-resonance frequencies at attachment points have the same value. In this paper, the method to calculate the anti-resonance frequencies and those sensitivities is presented. This sensitivity analysis is applied to the structural modification of the fixture excited at multi-points by the shaker. The antiresonance frequencies at the attachment points of the fixture can have the same value after structural modification, and the under-test in the vibration test control can be removed. Several computer simulations show that the proposed method can remove the under-tests, which are not removed in conventional vibration test control.

A Simple Screening Method for Anti-attachment Compounds Using Monospores of Porphyra yezoensis Ueda

  • Choi Jae-Suk;Kang Se-Eun;Cho Ji-Young;Shin Hyun-Woung;Hong Yong-Ki
    • Fisheries and Aquatic Sciences
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    • v.8 no.2
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    • pp.51-55
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    • 2005
  • We measured the anti-attachment activity of allelochemical and antifouling substances using monospores from Porphyra yezoensis Ueda as an assay. Methanol or aqueous extracts ($20/{\mu}g/mL$) from 32 seaweeds were added to monospore suspensions. Methanol extracts of Corallina pilulifera, Ishige sinicola, Sargassum horneri, and Sargassum sagamianum inhibited attachment $by\;>90\%$ compared to the reference. Phenolic compounds fractionated from S. sagamianum caused the most potent inhibition. P. yezoensis monospores also showed significant sensitivity to known allelochemical and algicidal compounds.

Attachment of Two-Way Shape Memory Alloy onto Fabric for Mass Production of Fire Fighters' Turnout Gear (지능형 소방복의 양산화를 위한 이방향 형상기억합금 부착 방법)

  • Park, Mi-Kyung;Lee, Ji-Yeon;Kim, Eun-Ae
    • Journal of the Korean Society of Clothing and Textiles
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    • v.36 no.4
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    • pp.382-390
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    • 2012
  • This study shows the optimum attachment of Two-Way Shape Memory Alloy (TWSMA) springs onto thermal liner and its sewing method for the mass production of fire fighter's intelligent turnout gear. SMA springs were attached to the fabric by four different methods and stitched by two different shapes (square and wave). The durability of the attached springs was tested by laundering up to 50 cycles. Examined were whether the springs would remain attached to the fabric after repeated laundering, the shape memory effect and reaction of the springs, and the anti-corrosiveness of the springs. A Human-Clothing-Environment simulator evaluated thermal insulation according to attachment methods, air layer volume, and stitch types. The findings showed that silicon attached springs remained intact after repeated laundering; in addition, repeated laundering did not influence the responsiveness and anti-corrosiveness of SMAs. Air volume had positive relations with the insulation. Attachment methods or stitch methods had limited impact on the thermal insulation. As a result, a wave type stitch with silicone attachment was suggested as the optimum method to attach the SMA springs onto the intelligent turnout gear for fire fighters.

Determinants Affecting Residents' Community Attachment in Rural Tourism Development (농촌관광 마을주민 지역사회애착심 영향요인 분석)

  • Park, Duk-Byeong
    • The Korean Journal of Community Living Science
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    • v.20 no.2
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    • pp.247-262
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    • 2009
  • A concept of community attachment was applied to investigate the residents' support for tourism development. This study aims to identify the factors influencing conflict management and community attachment on community resident in rural tourism villages. On-site survey with self-administered questionnaires was conducted for 348 residents in the rural tourism communities. Two distinct segments were identified by factor-clustering methods: functional-affective community attachment(80.72%) and anti-community attachment(19.28%). The characteristics of community residents with each type of community attachment were determined using a Bionomial Logistic Regression model. The most important determinants of positive community attachment were the degree of tourism business involvement, sex, and education. Therefore, some government supportive programs are needed to improve community attachment for the people who are under educated and females. In addition, the functional aspects of community attachment should be considered for rural tourism development.

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Retinopathy of prematurity: a review of epidemiology and current treatment strategies

  • Hong, Eun Hee;Shin, Yong Un;Cho, Heeyoon
    • Clinical and Experimental Pediatrics
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    • v.65 no.3
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    • pp.115-126
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    • 2022
  • Retinopathy of prematurity (ROP) is among the most common causes of childhood blindness. Three phases of ROP epidemics have been observed worldwide since ROP was first described in the 1940s. Despite advances in neonatal care, the occurrence of ROP and associated visual impairment has been increasing somewhere on Earth and remains difficult to control. Conventional treatment options for preventing ROP progression include retinal ablation using cryotherapy or laser therapy. With the emergence of anti-vascular endothelial growth factor (anti-VEGF) treatment for ocular diseases, the efficacy and safety of anti-VEGF therapy for ROP have recently been actively discussed. In the advanced stage of ROP with retinal detachment, surgical treatment including scleral buckling or vitrectomy is needed to maintain or induce retinal attachment. At this stage, the visual outcome is usually poor despite successful anatomical retinal attachment. Therefore, preventing ROP progression by timely screening examinations and treatment remains the most important part of ROP management.

Relations of Maternal Sensitivity and Temperament to linfants Attachment Security (영아의 애착 안정성에 영향을 미치는 변인 : 어머니의 민감성과 영아의 기질)

  • Park, Kyung Ja
    • Korean Journal of Child Studies
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    • v.20 no.3
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    • pp.3-17
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    • 1999
  • Maternal sensitivity and infant temperament were studied in relation to infant attachment security. Subjects were 47 one-year-old infants anti their mothers from intact upper-middle class families. Mothers sorted the Attachment Q-set (Waters, 1987, version 3.0) and filled out the Toddlers Temperament Questionnaire(Chu, 1992). Maternal sensitivity was observed in the home for two 3-hour sessions, and observers completed the Maternal Behavior Q-set(Pederson, Moran et al., 1990). Attachment security scores of the infants, using criterion scores developed with Korean infants, were 42, which is comparable to Previous studies. Infants who were securely attached to mothers showed more secure-based behaviors and compliance, enjoyed physical contacts, and showed less fussy/difficult behaviors with mothers. Mothers of girls were observed to be more sensitive to their infants' signals than mothers of boys. Maternal sensitivity scores were not related to infant security scores. However, maternal sensitivity was related to less compliance to mothers for boys.

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A Functional Role of Fibronectin Receptors in the Monocyte Differentiation (단핵구 분화에 있어서 Fibronectin 수용체의 역할)

  • 방옥선;강희갑박의균이영섭
    • The Korean Journal of Zoology
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    • v.37 no.4
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    • pp.592-596
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    • 1994
  • The interaction between fibronectin (FN) and its receptors controls cell attachment and migration, two crucial events during monocyte development and differentiation. To investigate the functional role of FN and its receptor, we have studied adhesion of monocyte to two different regions of FN (38- and 85-kDa domain), as well as the expression of the integrin during monocle differentiation. Anti-integrin Rl subunit antibody completely blocked the attachment of FN-coated latex beads to macrophage, but the effect of anti-integrin u4 antibody was much less significant. Rat monocyte expressed integrin $u4\beta1$ predominantly, while macrophage expressed $\alpha5\beta1$ as analyzed tv flow cvtometer and western blot. From these results, it can be suggested that these two integrins plan different roles during monocyte differentiation.

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Evaluation of Endothelial Cell Attachment on Polymer Surface (고분자 표면의 혈관내피세포 부착력에 관한 연구)

  • Choi, Jin-Wook;Ryu, Gyu-Ha;Min, Byoung-Goo
    • Journal of Biomedical Engineering Research
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    • v.11 no.1
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    • pp.131-140
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    • 1990
  • To improve antithrombogenicity of polymer that used in vascular graft and artificial organs, seeding of human endothelial cells on the polyurethane was studied. Human endothelial cells were ismlated from human umbilical veins, using type I collagenase, and identified with goat anti vWF antibodies. Human endothilial cell seeding was tried upon the polyurethane which has good mechanical property and resists stresses. The hydrophobic polyurethane surface was changed hydrophilic by corona discharf:e treatment. Surface hydrophilicity was measured with Wilhemly plate method and the goniometer. To evaluate matrix protein adsorption, fibronectin adsorption test was done. To eveluate cell adhesion, human endothelial cell attachment forces were measured rising a perfusion chamber of , ism diamter. Less cells were detached from the hydrophilically treated polyurethane. This showed that corona discharge on the polyurethane could improve matrix adsorption and endothelial cell attachment.

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Effects of host modulation by nonsteroidal anti-inflammatory drugs on periodontal disease: a systematic review and meta-analysis (비스테로이드성 항염증제를 이용한 숙주조절이 치주질환에 미치는 영향: 체계적 고찰 및 메타 분석)

  • Kang, Dae-Young;Cho, In-Woo;Shin, Hyun-Seung;Ahn, Hyeong-Sik;Kim, Hyun-Jung;Park, Jung-Chul
    • Journal of Dental Rehabilitation and Applied Science
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    • v.33 no.1
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    • pp.7-18
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    • 2017
  • Purpose: Nonsteroidal anti-inflammatory drugs that prohibit biosynthesis of arachidonic acid metabolites have been considered potent host modulation agents. The aim of this review was to determine the effect of nonsteroidal anti-inflammatory drugs adjunctive with nonsurgical periodontal treatment in patients with periodontal disease. Materials and Methods: Three electronic databases were searched to identify relevant studies. The methodological quality and mean differences of the change in clinical attachment level and probing depth were analyzed according to Cochrane review methods. Results: Twelve studies were included in the methodological assessment and nine studies were suitable for inclusion in the meta-analysis. The mean difference in the clinical attachment level gain did not differ significantly between the nonsteroidal anti-inflammatory drugs and control groups at any observation time. The highest mean difference in clinical attachment level gain was 0.30 mm at 4 weeks (95% confidence interval = -0.37 to 0.97). There was a significant mean difference in the probing depth reduction, of 0.34 mm (95% confidence interval = 0.29 to 0.40) at 6 weeks. Conclusion: Therefore, nonsteroidal anti-inflammatory drugs have additional therapeutic effect when administrated with nonsurgical periodontal treatment.

Conjugation of mono-sulfobetaine to alkyne-PPX films via click reaction to reduce cell adhesion

  • Chien, Hsiu-Wen;Keng, Ming-Chun;Chen, Hsien-Yeh;Huang, Sheng-Tung;Tsai, Wei-Bor
    • Biomaterials and Biomechanics in Bioengineering
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    • v.3 no.1
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    • pp.59-69
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    • 2016
  • A surface resisting protein adsorption and cell adhesion is highly desirable for many biomedical applications such as diagnostic devices, biosensors and blood-contacting devices. In this study, a surface conjugated with sulfobetaine molecules was fabricated via the click reaction for the anti-fouling purpose. An alkyne-containing substrate (Alkyne-PPX) was generated by chemical vapor deposition of 4-ethynyl-[2,2]paracyclophane. Azide-ended mono-sulfobetaine molecules were synthesized and then conjugated on Alkyne-PPX via the click reaction. The protein adsorption from 10% serum was reduced by 57%, while the attachment of L929 cells was reduced by 83% onto the sulfobetaine-PPX surface compared to the protein adsorption and cell adhesion on Alkyne-PPX. In conclusion, we demonstrate that conjugation of mono-sulfobetaine molecules via the click chemistry is an effective way for reduction of non-specific protein adsorption and cell attachment.