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The Crystal Structure of 2-Methyl-3-(N-trimethyl ammonium)phenol Iodide (2-Methyl-3-(N-trimethyl ammonium)phenol Iodide의 결정 구조)

  • 조성일;윤혜숙;구정회
    • YAKHAK HOEJI
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    • v.24 no.2
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    • pp.135-141
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    • 1980
  • The crystal and molecular structure of 2-methyl-3-(N-trimethyl ammonium)phenol iodide, $C_{10}H_{16}NOI, was determined by X-ray diffraction method. The compound crystallizes in the orthorhombic space group $P_{na2}_{1}$ with a=13.327(3), b=12.496(3), C=7.227(2)A and Z=4. A total of 489 independent observed reflections were collected by the automated Four-circle diffractometer and was solved by heavy atom method and refined by anisotropic block-diagonal least-squares method to the R value of 0.04. The benzene ring is slightly distorted from regular hexagon. The I atom and 2-methyl-3-(N-trimethyl ammonium)phenol group is held together by van der Waals forces in the crystal. Intermolecular hydrogen bond is of the type O-H....I with the length 3.35.angs.. Apart from the hydrogen bonding system the molecules are held together by van der Waals forces in the crystal.

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Lupane-Triterpenes from the Leaves of Brassaiopsis glomerulata

  • Kiem, Phan-Van;Dat, Nguyen-Tien;Minh, Chau-Van;Lee, Jung-Joon;Kim, Young-Ho
    • Archives of Pharmacal Research
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    • v.26 no.8
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    • pp.594-596
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    • 2003
  • Three known lupane-triterpenes, 3a-hydroxy-lup-20(29)-en-23,28-dioic acid (1), 3$\alpha$-hydroxylup-20(29)-en-23,28-dioic acid 28-Ο-$\alpha$-L-rhamnopyranosyl-(1$\rightarrow4)-\beta-D-glucopyranosyl-(1\rightarow6)-\beta$-D-glucopyranosyl ester (acankoreoside A, 2) and $3\alpha$, $11\alpha$-dihydroxy-23-oxo-lup-20(29)-en-28-oic acid (3) were isolated from the leaves of Brassaiopsis glomerulata (Blume) Regel, a species of Araliaceae family growing in Vietnam. Their structures were determined on the basis of spectroscopic data.

Integer and fractional quantum Hall effect in graphene heterostructure

  • Youngwook Kim
    • Progress in Superconductivity and Cryogenics
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    • v.25 no.1
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    • pp.1-5
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    • 2023
  • The study of two-dimensional electron systems with extraordinarily low levels of disorder was, for a long time, the exclusive privilege of the epitaxial thin film research community. However, the successful isolation of graphene by mechanical exfoliation has truly disrupted this field. Furthermore, the assembly of heterostructures consisting of several layers of different 2D materials in arbitrary order by exploiting van der Waals forces has been a game-changer in the field of low-dimensional physics. This technique can be generalized to the large class of strictly 2D materials and offers unprecedented parameters to play with in order to tune electronic and other properties. It has led to a paradigm shift in the field of 2D condensed matter physics with bright prospects. In this review article, we discuss three device fabrication techniques towards high mobility devices: suspended structures, dry transfer, and pick-up transfer methods. We also address state-of-the-art device structures, which are fabricated by the van der Waals pick-up transfer method. Finally, we briefly introduce correlated ground states in the fractional quantum Hall regime.

Healthcare Workers' Knowledge and Attitudes Regarding the World Health Organization's "My 5 Moments for Hand Hygiene": Evidence From a Vietnamese Central General Hospital

  • Van Nguyen, Huy;Tran, Hieu Trung;Khuong, Long Quynh;Van Nguyen, Thanh;Ho, Na Thi Nhi;Dao, An Thi Minh;Van Hoang, Minh
    • Journal of Preventive Medicine and Public Health
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    • v.53 no.4
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    • pp.236-244
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    • 2020
  • Objectives: Although the World Health Organization (WHO) initiative "My 5 Moments for Hand Hygiene" has been lauded as effective in preventing hospital-associated infections, little is known about healthcare workers (HCWs)' hand hygiene behavior. In this study, we sought to assess knowledge and attitudes towards the concepts in this initiative, as well as associated factors, among Vietnamese HCWs at a general hospital. Methods: A structured questionnaire was administered to HCWs at a central Vietnamese general hospital in 2015. Multiple logistic regression analysis was used to identify factors associated with HCWs' knowledge and attitudes towards hand hygiene. Results: Of 120 respondents, 65.8% and 67.5% demonstrated appropriate knowledge and a positive attitude, respectively, regarding all 5 hand hygiene moments. Logistic regression indicated better knowledge of hand hygiene in workers who were over 30 years old, who were direct HCWs (rather than managers), who had frequent access to clinical information, and who received their clinical information from training. Those who worked in infectious and tropical disease wards, who had frequent access to clinical information, and who received information from training were more likely to have a positive attitude towards hand hygiene than their counterparts. Conclusions: Although many Vietnamese HCWs displayed moderate knowledge and positive attitudes towards the WHO hand hygiene guidelines, a key gap remained. Regular education and training programs are needed to increase knowledge and to improve attitudes and practices towards hand hygiene. Furthermore, a combination of multimodal strategies and locally-adapted interventions is needed for sustainable hand hygiene adherence.

A Phenomenological Study on the Lived Experiences of Middle-aged People with Disabilities after a Stroke (중년기 뇌졸중 장애인의 삶에 관한 해석학적 현상학 연구)

  • Kim, Mi Ok;Choi, Jung Min;Kang, Seung Won
    • Korean Journal of Social Welfare
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    • v.65 no.1
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    • pp.33-58
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    • 2013
  • This study aims to explore the lived experiences of middle-aged people with disabilities after a stroke. Using van Manen's phenomenological qualitative method, this study obtained information through interviews with middle-aged people with disabilities after a stroke. The following main themes were extracted from the lived experiences of middle-aged people with disabilities who were interviewed: 'a life broken in half', 'discontinuity and isolation of life', 'being born again', 'fear of stroke relapse', and 'overcoming all difficulties through harmony in a family'. Therefore, the core theme on the lived experiences of middle-aged people with disabilities after a stroke is a shadow of relapse over lives that have to protect families. The implication of this study's results on policy making and actual practices are discussed focusing on the well-being of people with disabilities and their families.

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An Algorithm for Labia Minora Reduction Based on a Review of Anatomical, Configurational, and Individual Considerations

  • Maurits Lange;J. Joris Hage;Refaat B. Karim;Frederic Amant
    • Archives of Plastic Surgery
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    • v.50 no.1
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    • pp.17-25
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    • 2023
  • A variety of reduction labiaplasty techniques have been introduced to date, but no single technique will offer the optimal solution for every patient. Rather, the technique should be chosen based on anatomical, configurational, and technical considerations, as well as on patients' personal preferences regarded maintenance of the labial rim, maintenance of labial sensitivity, and prevention of iatrogenic thickening of the labium. We reviewed, defined, and assessed labial configurational variety, neurovascular supply, reduction techniques, and patient's preferences as the considerations relevant to the choice of labiaplasty technique. Based on this review, an algorithm was constructed that leads to a choice of reduction technique through five decisions to be made regarding (1) resection or (partial) retention of the labial free rim, (2) the measure of required labial width reduction, (3) labial vascular status, (4) prevention of iatrogenic labial thickening, and (5) preservation of labial sensibility. The choice of techniques includes edge trimming, central spindle form de-epithelialization or full-thickness resection, and three modifications of the wedge resection or de-epithelialization technique. These three modifications comprised a modified anterior resection or de-epithelialization combined with posterior flap transposition, a custom flask resection or de-epithelialization, and a modified posterior wedge resection or de-epithelialization combined with anterior flap transposition. Use of the five decisional steps and the inclusion of modifications of all three conventional reduction techniques offer an improved algorithm for the choice of labioplasty technique.

Study on the Space in Works of Mies Van der Rohe in Terms of Text - Focused on Tugendhat, Hubbe House and Barcelona Pavilion - (Text 측면에서 본 Mies Van der Rohe 작품의 공간성 연구 - Tugendhat, Hubbe 주택과 Barcelona Pavilion을 중심으로 -)

  • Yook, Ok-Soo
    • Journal of the Korean housing association
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    • v.25 no.6
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    • pp.101-109
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    • 2014
  • It was early in the $20^{th}$ century when the space was begun to say through the mutual circumstances of form and contents. Adrian Forty explained that the characteristics of space can be divided into three steps by the period: a space of enclosure, a space as continuum and a space as an extension of the body. And there is common condition that all three spaces are accompanied by the form. In the new thinking of architectural form in terms of text in modern society, architecture becomes to more complex to understanding. Saying that there is nothing outside text (Il n'y a rien en dehors du text.) in the world, Jacques Derrida insisted the world to be texted and not to be special centrality, where can be existed by difference and delay its meaning. Text is the structural meaning (sign), not a metaphorical one (symbol). Without the symbol, the architecture can be recognized as text with signing to the form. For that, there is a question how can be explained the space in terms of text extracting the meaning and the symbol. Absolutely not intended by Mies van der Rohe, but in his works of houses and pavilion, its characteristics and traces of text can be seen. If it is possible to analyse his works in the textual view, space of Mies will be found in the same direction of text. And it will be an important opportunity to re-evaluate the space of Mies works standing in the heart of Modern Architecture.

Buckling analysis of double walled carbon nanotubes embedded in Kerr elastic medium under axial compression using the nonlocal Donnell shell theory

  • Timesli, Abdelaziz
    • Advances in nano research
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    • v.9 no.2
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    • pp.69-82
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    • 2020
  • In this paper, a new explicit analytical formula is derived for the critical buckling load of Double Walled Carbon Nanotubes (DWCNTs) embedded in Winkler elastic medium without taking into account the effects of the nonlocal parameter, which indicates the effects of the surrounding elastic matrix combined with the intertube Van der Waals (VdW) forces. Furthermore, we present a model which predicts that the critical axial buckling load embedded in Winkler, Pasternak or Kerr elastic medium under axial compression using the nonlocal Donnell shell theory, this model takes into account the effects of internal small length scale and the VdW interactions between the inner and outer nanotubes. The present model predicts that the critical axial buckling load of embedded DWCNTs is greater than that without medium under identical conditions and parameters. We can conclude that the embedded DWCNTs are less susceptible to axial buckling than those without medium.

Pentacyclic Triterpenoids from Mallotus apelta

  • Kiem, Phan-Van;Minh, Chau-Van;Huong, Hoang-Thanh;Nam, Nguyen-Hoai;Lee, Jung-Joon;Kim, Young-Ho
    • Archives of Pharmacal Research
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    • v.27 no.11
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    • pp.1109-1113
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    • 2004
  • A new triterpene (1) and six known pentacyclic terpenoids (2-7) were isolated from the methanol extract of the dried leaves from Mallotus apelta. Based on the spectral and chemical evidence, their structures were determined to be 3$\alpha$-hydroxyhop-22(29)-ene (1), hennadiol (2), friedelin (3), friedelanol (4), epifriedelanol (5), taraxerone (6), and epitaraxerol (7).

PREDICTION MEAN SQUARED ERROR OF THE POISSON INAR(1) PROCESS WITH ESTIMATED PARAMETERS

  • Kim Hee-Young;Park You-Sung
    • Journal of the Korean Statistical Society
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    • v.35 no.1
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    • pp.37-47
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    • 2006
  • Recently, as a result of the growing interest in modeling stationary processes with discrete marginal distributions, several models for integer valued time series have been proposed in the literature. One of these models is the integer-valued autoregressive (INAR) models. However, when modeling with integer-valued autoregressive processes, the distributional properties of forecasts have been not yet discovered due to the difficulty in handling the Steutal Van Ham thinning operator 'o' (Steutal and van Ham, 1979). In this study, we derive the mean squared error of h-step-ahead prediction from a Poisson INAR(1) process, reflecting the effect of the variability of parameter estimates in the prediction mean squared error.