• Title/Summary/Keyword: Molecular Communication

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Design and Simulation Study on Three-terminal Graphene-based NEMS Switching Device (그래핀 기반 3단자 NEMS 스위칭 소자 설계 및 동작 시뮬레이션 연구)

  • Kwon, Oh-Kuen;Kang, Jeong Won;Lee, Gyoo-Yeong
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.8 no.6
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    • pp.939-946
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    • 2018
  • In this work, we present simple schematics for a three-terminal graphene-based nanoelectromechanical switch with the vertical electrode, and we investigated their operational dynamics via classical molecular dynamics simulations. The main structure is both the vertical pin electrode grown in the center of the square hole and the graphene covering on the hole. The potential difference between the bottom gate of the hole and the graphene of the top cover is applied to deflect the graphene. By performing classical molecular dynamic simulations, we investigate the nanoelectromechanical properties of a three-terminal graphene-based nanoelectromechanical switch with vertical pin electrode, which can be switched by the externally applied force. The elastostatic energy of the deflected graphene is also very important factor to analyze the three-terminal graphene-based nanoelectromechanical switch. This simulation work explicitly demonstrated that such devices are applicable to nanoscale sensors and quantum computing, as well as ultra-fast-response switching devices.

The Variation of Offset Ink Properties according to the Vegetable Oil Estersr (Vegetable Oil Esters에 따른 Offset 잉크의 물성 변화에 관한 연구)

  • Park, Jung-Min;Kim, Sung-Bin
    • Journal of the Korean Graphic Arts Communication Society
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    • v.30 no.1
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    • pp.1-19
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    • 2012
  • According as gradually increasing the demand for eco-friendly at the printing process, it has been progressed fairly development. Especially, the inks are used by soy oil beginning of ink industry for preventing environment, it is possible to make eco-friendly inks with vegetable ester. So it is not necessary to use petroleum-based solvents at all for preventing environment. These eco-friendly inks have a benefits they are able to use the renewable resource. But basically vegetable oils have that reduce the VOC(Volatile Organic Compound) and high viscosity, high solubility properties. So if the vegetable oils use in the ink, set off problem occur on the paper because of slow drying time. In case of vegetable ester, it has similar the molecular weight and kinetic viscosity with hydrocarbon solvent, it is able to control the power of dilution about the resin. So, it has benefit that solve the problem of the existing eco-friendly inks. In this study, different types of ester were made by six types of vegetable oils and used ester in the varnishes and inks properties are comparison with hydrocarbon solvent based ink. By considering the intrinsic properties of vegetable oil, ester used to analyze the changes in ink properties, using ester varnish is applied to study the rheology characteristics and emulsification with inks.

Examination of the Presence and Differential Expression of Connexin Isoforms in the Urinary Bladder of the Male Rat During Postnatal Period

  • Lee, Ki-Ho
    • Journal of Animal Science and Technology
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    • v.54 no.6
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    • pp.419-425
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    • 2012
  • The coordinated action of the detrusor muscle cells in the urinary bladder is governed by cell-cell communication through gap junction, consisted of connexin (Cx) molecules. Even though a number of researches have been mostly focused on expressional changes of a few Cx isoforms in clinically dysfunctional condition of the bladder, less attention has been paid for investigation of Cx isoforms present in the bladder. Using real-time PCR analysis, the present study examined Cx isoforms expressing in the male rat bladder during postnatal period. Also, expressional patterns of Cx isoforms were evaluated in the bladder at different postnatal ages. Of a total of 13 Cx isoforms tested in the present study, we were able to detect mRNAs of 6 Cx isoforms in the rat urinary bladder, including Cxs 31, 31.1, 32, 37, 40, and 45. The transcript levels of Cxs 31, 31.1, 37, 40, and 45 were gradually increased from 1 week of age until 25 days of age, followed by transient decreases at 45 days of age. However, abundance of Cx32 transcript was drastically increased at 15 days of age, followed by a sharp drop at 45 days of age. These results indicate that differential expression of Cx isoforms in the bladder during postnatal development would be necessary for maintaining proper function of the bladder. A question remains to be answered if significant decreases of transcript levels of some Cx isoforms at the elderly are associated with age-dependent dysfunction of the bladder.

The Study on Volumetric Transition Polymer Gel (체적상전이고분자 겔에 관한 연구)

  • 김정곤
    • Journal of the Korean Graphic Arts Communication Society
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    • v.14 no.1
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    • pp.47-54
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    • 1996
  • Deuterium NMR studies have been carried out for two kinds of main- chain dimer liquid crystals $\alpha$.$\omega$-bis[(4,4`-cyanobipheny0oxy] alkane (CBA-n, n=9,100.The H-NMR spectra were recorded on a JEOP JNM-GSX-500 spectrometer by using deuterium labelled CBA-n at various temperatures. The RIS analysis of the NMR spectra was performed so as to elucidate the conformational characteristics of the spacer in the nematic phase. Following the previous treatment, the single-ordering-matrix model was adopted, in which the molecular axis was defined parallel to the line connecting the centers of the terminal mesogenic cores. Conformer fractions of the spacer were estimated by simulation so as to reproduce the observed NMR profile. The conformational entropy changes at both CN and NI interphases were estimated on the basis of the nematic conformations taken from the conformation map as well as those derived from the simulation. In these calculations the spacer was assumed th by in the all-trans conformation and in the random coil stats in the crystal and isotropic phases respectively. The esimated conformational entropy change values were then compared with the corresponding constant-volume entropies obtained from PVT measurements. The correspondence between both entropy values was found to be quite good in consideration of the uncertainties involved in both experiment and calculations.

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Mitochondria: multifaceted regulators of aging

  • Son, Jyung Mean;Lee, Changhan
    • BMB Reports
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    • v.52 no.1
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    • pp.13-23
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    • 2019
  • Aging is accompanied by a time-dependent progressive deterioration of multiple factors of the cellular system. The past several decades have witnessed major leaps in our understanding of the biological mechanisms of aging using dietary, genetic, pharmacological, and physical interventions. Metabolic processes, including nutrient sensing pathways and mitochondrial function, have emerged as prominent regulators of aging. Mitochondria have been considered to play a key role largely due to their production of reactive oxygen species (ROS), resulting in DNA damage that accumulates over time and ultimately causes cellular failure. This theory, known as the mitochondrial free radical theory of aging (MFRTA), was favored by the aging field, but increasing inconsistent evidence has led to criticism and rejection of this idea. However, MFRTA should not be hastily rejected in its entirety because we now understand that ROS is not simply an undesired toxic metabolic byproduct, but also an important signaling molecule that is vital to cellular fitness. Notably, mitochondrial function, a term traditionally referred to bioenergetics and apoptosis, has since expanded considerably. It encompasses numerous other key biological processes, including the following: (i) complex metabolic processes, (ii) intracellular and endocrine signaling/communication, and (iii) immunity/inflammation. Here, we will discuss shortcomings of previous concepts regarding mitochondria in aging and their emerging roles based on recent advances. We will also discuss how the mitochondrial genome integrates with major theories on the evolution of aging.

An Improved Decoding Scheme of Hamming Codes using Soft Values (소프트 값을 이용한 해밍 부호의 개선된 복호 방식)

  • Cheong, Ho-Young
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.12 no.1
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    • pp.37-42
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    • 2019
  • In this paper, we propose a syndrome decoding scheme that can correct two errors for single error correcting Hamming codes within a code length. The decoding scheme proposed in this paper has the advantage of significantly improving the error rate performance compared to the decoder complexity by correcting multiple errors without substantially increasing the decoding complexity. It is suitable for applications in which the energy use of encoder/decoder is extremely limited and the low error rate performance is required, such as IoT communications and molecular communications. In order to verify the improvement of the error rate performance of the Hamming code with the proposed decoding scheme, we performed simulation on Hamming codes with short code length in the AWGN and BPSK modulation environments. As a result, compared with the conventional decoding method, the proposed decoding scheme showed performance improvement of about 1.1 ~ 1.2[dB] regardless of the code length of the Hamming code.

Sensing the Stress: the Role of the Stress-activated p38/Hog1 MAPK Signalling Pathway in Human Pathogenic Fungus Cryptococcus neoformans

  • Bahn, Yong-Sun;Heitman, Joseph
    • Proceedings of the Microbiological Society of Korea Conference
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    • 2007.05a
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    • pp.120-122
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    • 2007
  • All living organisms use numerous signal-transduction pathways to sense and respond to their environments and thereby survive and proliferate in a range of biological niches. Molecular dissection of these signalling networks has increased our understanding of these communication processes and provides a platform for therapeutic intervention when these pathways malfunction in disease states, including infection. Owing to the expanding availability of sequenced genomes, a wealth of genetic and molecular tools and the conservation of signalling networks, members of the fungal kingdom serve as excellent model systems for more complex, multicellular organisms. Here, we employed Cryptococcus neoformans as a model system to understand how fungal-signalling circuits operate at the molecular level to sense and respond to a plethora of environmental stresses, including osmoticshock, UV, high temperature, oxidative stress and toxic drugs/metabolites. The stress-activated p38/Hog1 MAPK pathway is structurally conserved in many organisms as diverse as yeast and mammals, but its regulation is uniquely specialized in a majority of clinical Cryptococcus neoformans serotype A and D strains to control differentiation and virulence factor regulation. C. neoformans Hog1 MAPK is controlled by Pbs2 MAPK kinase (MAPKK). The Pbs2-Hog1 MAPK cascade is controlled by the fungal "two-component" system that is composed of a response regulator, Ssk1, and multiple sensor kinases, including two-component.like (Tco) 1 and Tco2. Tco1 and Tco2 play shared and distinct roles in stress responses and drug sensitivity through the Hog1 MAPK system. Furthermore, each sensor kinase mediates unique cellular functions for virulence and morphological differentiation. We also identified and characterized the Ssk2 MAPKKK upstream of the MAPKK Pbs2 and the MAPK Hog1 in C. neoformans. The SSK2 gene was identified as a potential component responsible for differential Hog1 regulation between the serotype D sibling f1 strains B3501 and B3502 through comparative analysis of their meiotic map with the meiotic segregation of Hog1-dependent sensitivity to the fungicide fludioxonil. Ssk2 is the only polymorphic component in the Hog1 MAPK module, including two coding sequence changes between the SSK2 alleles in B3501 and B3502 strains. To further support this finding, the SSK2 allele exchange completely swapped Hog1-related phenotypes between B3501 and B3502 strains. In the serotype A strain H99, disruption of the SSK2 gene dramatically enhanced capsule biosynthesis and mating efficiency, similar to pbs2 and hog1 mutations. Furthermore, ssk2, pbs2, and hog1 mutants are all hypersensitive to a variety of stresses and completely resistant to fludioxonil. Taken together, these findings indicate that Ssk2 is the critical interface protein connecting the two-component system and the Pbs2-Hog1 pathway in C. neoformans.

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Electronic Properties of MIM Structure for application in Communication Device (통신소자 응용을 위한 MIM 구조 유기박막의 전자특성)

  • Choi, Young-Il;Song, Jin-Won;Lee, Kyung-Sup
    • Proceedings of the IEEK Conference
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    • 2005.11a
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    • pp.1279-1282
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    • 2005
  • Maxwell displacement current (MDC) measurement has been employed to study the dielectric property of Langmuir-films. MDC flowing across monolayers is analyzed using a rod-like molecular model. LB layers of Arachidic acid deposited by LB method were deposited onto slide glass as Y-type film. The structure of manufactured device is Au/Arachidic acid/Al, the number of accumulated layers are $3{\sim}9$. Also, we then examined of the MIM device by means of I-V. The I-V characteristic of the device is measured from -3 to +3[V].

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Shade Avoidance and the Regulation of Leaf Inclination in Rice

  • Shin, Juhee;Park, Phun Bum
    • Rapid Communication in Photoscience
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    • v.3 no.3
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    • pp.53-55
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    • 2014
  • The shade avoidance syndrome is a morphological and physiological response when plants are exposed to shade. Recent work in Arabidopsis had begun to define the molecular components of the shade avoidance syndrome in dicotyledonous model plant. However, little is known about the shade avoidance response networks in agriculturally important monocotyledon crops such as rice. Here, we found that the degree of bending at the lamina joint is inversely proportional to the R:FR ratio. To elucidate which phytochrome is involved in this response, we did lamina joint inclination assay with the rice phytochrome-deficient mutants (osphyA, osphyB, and osphyC) and the wild type plants. Whereas the osphyA and osphyC knockout mutants bent at the lamina joint in the far-red rich condition as the wild type plants, the osphyB knockout mutants no longer bent at the lamina joint in the far-red rich condition. These results suggest that PHYB acts as a sole photoreceptor in the lamina joint inclination response in rice.

Interdomain Signaling in Stem Cell Maintenance of Plant Shoot Meristems

  • Bleckmann, Andrea;Simon, Rudiger
    • Molecules and Cells
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    • v.27 no.6
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    • pp.615-620
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    • 2009
  • The plant shoot meristem maintains a group of stem cells that remain active throughout the plant life. They continuously generate new cells that are then recruited for organ initiation in the peripheral zone. Stem cell proliferation and daughter cell differentiation has to be integrated with overall growth and development of the diverse functional domains within the shoot apex. Several studies have revealed extensive communication between these domains. The signaling mechanisms employed comprise diffusible peptides, directional transport of plant hormones, but also complex interactions between transcription factors, that together establish a panoply of regulatory inputs that fine-tune stem cell behavior in the shoot meristem.