• 제목/요약/키워드: Cell formation

검색결과 4,024건 처리시간 0.03초

Resistive Memory Switching in Ge5Se5 Thin Films

  • Kim, Jang-Han;Hwang, Yeong-Hyeon;Chung, Hong-Bay
    • 한국진공학회:학술대회논문집
    • /
    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
    • /
    • pp.326-326
    • /
    • 2014
  • It has been known since the mid 1960s that Ag can be photodissolved in chalcogenide glasses to form materials with interesting technological properties. In the 40 years since, this effect has been used in diverse applications such as the fabrication of relief images in optical elements, micro photolithographic schemes, and for direct imaging by photoinduced Ag surface deposition. ReRAM, also known as conductive bridging RAM (CBRAM), is a resistive switching memory based on non-volatile formation and dissolution of a conductive filament in a solid electrolyte. Especially, Ag-doped chalcogenide glasses and thin films have become attractive materials for fundamental research of their structure, properties, and preparation. Ag-doped chalcogenide glasses have been used in the formation of solid electrolyte which is the active medium in ReRAM devices. In this paper, we investigated the nature of thin films formed by the photo-dissolution of Ag into Ge-Se glasses for use in ReRAM devices. These devices rely on ion transport in the film so produced to create electrically programmable resistance states [1-3]. We have demonstrated functionalities of Ag doped chalcogenide glasses based on their capabilities as solid electrolytes. Formation of such amorphous systems by the introduction of Ag+ ions photo-induced diffusion in thin chalcogenide films is considered. The influence of Ag+ ions is regarded in terms of diffusion kinetics and Ag saturation is related to the composition of the hosting material. Saturated Ag+ ions have been used in the formation of conductive filaments at the solid electrolyte which is the active medium in ReRAM devices. Following fabrication, the cell displays a metal-insulator-metal structure. We measured the I-V characteristics of a cell, similar results were obtained with different via sizes, due to the filamentary nature of resistance switching in ReRAM cell. As the voltage is swept from 0 V to a positive top electrode voltage, the device switches from a high resistive to a low resistive, or set. The low conducting, or reset, state can be restored by means of a negative voltage sweep where the switch-off of the device usually occurs.

  • PDF

도홍사물탕(挑紅四物湯)이 C6 신경교세포의 2-DG에 의한 오토파지성 세포사멸에 미치는 영향 (Protective Effects of Dohongsamul-tang on 2-deoxy-D-glucose Induced Autophagic Cell Death in C6 Glial Cells)

  • 신학수;이성근;문병순
    • 동의생리병리학회지
    • /
    • 제23권3호
    • /
    • pp.581-589
    • /
    • 2009
  • The water extract of Dohongsamul-tang(DHSMT) has been traditionally used in treatment of ischemic heart and brain diseases in Oriental Medicine. However, little is known about the mechanism by which DHSMT protects C6 glial cells from glucose deprevation induced damages. Therefore, this study was designed to evaluate the protective effects of DHSMT on 2-deoxy-D-glucose induced autophagy of C6 glial cells. Autophagic phenotype is evaluated by fluorescence microscopy and flow cytometry with specific biological staining dyes, including monodansylcadaverine and acridine orange, as well as Western blot analysis with microtubule-associated protein 1 light chain 3(LC3) and Beclin-1. Treatment with 2-deoxy-D-glucose significantly resulted in a decrease of the viability of C6 glial cells and increase of the extracellular LDH release in a dose and time-dependent manner. However, pretreatment with DHSMT protected C6 glial cells from glucose deprivation with 2-deoxy-D-glucose. The author also observed the fact that autophagy phenotype occurred by 2-deoxy-D-glucose in C6 glial cells. Pretreatment with 3-MA, a pharmacological inhibitior of autophagy, abolished the formation of acidic vesicle organelle in C6 glial cells treated with 2-deoxy-D-glucose. However, pretreatment with DHSMT inhibited the formation of autophagic phenotypes, including formation of acidic vesicle organelle, and increase of the expression of LC-3 II Beclin-1 proteins in C6 glial cells treated with 2-deoxy-D-glucose. Taken together, these data suggest that DHSMT is able to protect C6 glial cells from glucose deprivation with marked inhibition of autophagy formation.

고온성 Clostridium thermocellum과 Clostridium thermohydrosulfuricum의 원형질체 형성 및 재생 (Protoplast Formation and Regeneration of Thermophilic Clostridium thermocellum and Clostridium thermohydrosulfuricum)

  • 김욱한;정기택;이용현
    • 미생물학회지
    • /
    • 제28권4호
    • /
    • pp.304-310
    • /
    • 1990
  • 고온 혐기성 Clostridium thermocellum 및 Clostridium thermohydrosulfuricum의 원형질체 형성 및 재생조건에 대하여 조사하였다. 원형질체 형성은 C. thermocellum의 경우, 0.2% glycine을 첨가한 배지에서 초기대수증식까지 생육한 cell을 0.5mg/ml의 lysozyme을 함유한 100mM TMG buffer(pH 7.5)에서 $37^{\circ}C$, 2시간 처리 했을 때 가장 좋았으며, C. thermohydrosulfuricum은 대수증식기의 cell을 동일 조건에서 0.2mg/ml의 lysozyme으로 처리했을 때 양호하였다. 원형질체 재생은 0.3-0.4M sorbitol. 0.5% casamino acid, 고농도의 $CaCl_2$를 첨가한 재생배지에서 $60^{\circ}C$, 7-10일간 배양했을 때 잘 되었으며, 원형질체 형성시 lysozyme의 처리 시간이 짧을 수록 좋았다. 재생빈도는 C. thermocellum의 경우 $4.85{\times}10^{-3}$, C. thermohydrosulfuricum의 경우 $4.23{\times}10^{-2}$ 이하로 낮은 편이었다. 재생배지에 나타난 colony에는 완전히 재생되지 않은 L-form cell도 함께 존재하였다.

  • PDF

Streptomyces fradiae에서 균 성장속도에 의한 tylosin 생합성 조절 (Regulation of Tylosin Biosynthesis by Cell Growth Rate in Streptomyces fradiae)

  • 강현아;이정현;이계준
    • 미생물학회지
    • /
    • 제25권4호
    • /
    • pp.353-359
    • /
    • 1987
  • 균 성장속도가 tylosin 생합성에 미치는 영향을 조사하기 위하여, 여러 성장속도로 배양한 균체내에서 oxaloacetate 대사에 관여하는 효소들의 활성을 살펴보았다. 그 결과, 비 tylosin 생합성 속도($q_{p}$ )는 성장속도 $0.013h^{-1}$까지는 성장속도와 함께 증가하지만, 더 높은 성장속도에선 감소됨을 알 수 있었다. Citrate synthase, aspartate aminotransferase와 PEP carboxylase의 활성 및 합성은 $0.013h^{-1}$ 보다 낮은 성장속도에선 매우 낮게 나타났으며, 반면 methylmaionyl-CoA carboxyltransferase의 활성 및 합성은 tylosin 생합성과 마찬가지로 높은 성장속도에선 감소되었다. 따라서 tylosin 생합성은 균 성장속도에 의해 조절됨을 명백히 알 수 있었다.

  • PDF

Radioprotective Effect of Panax ginseng against Giant Cell Formation in The Testis of Irradiated Mice

  • Kumar Madhu;Saxena Preeti S.
    • 고려인삼학회:학술대회논문집
    • /
    • 고려인삼학회 2002년도 학술대회지
    • /
    • pp.385-391
    • /
    • 2002
  • Panax ginseng (family- Araliaceae) is a native plant of Korea and has been used for past several years among oriental people. To evaluate the radioprotective potential of P. ginseng on the formation of giant cells in the testis of Swiss albino mice, the animals were divided into four groups: -(I)-Only vehicle was administered. (II)P. ginseng treated group: -The animals received 10 mg/kg body weight P. ginseng root extract (in DDW) i.p. continuously for 30 days. (III) Irradiated group: -The animals were exposed to 8 Gy gamma radiation at the dose rate of 1.69 Gy/min at the distance of 80 ems. (IV) Combined treatment group: -Animals were given P. ginseng extract for four days and on fourth day they were irradiated to 8 Gy gamma radiation after 30 minute of extract administration. The animals of these three groups were autopsied on day 1,3, 7, 14 and 30 days. In ginseng treated group, active spermatogenesis was observed without any toxic effect. Histopathological studies of irradiated group (II) revealed reduction in germ cell count, loss of sperms and formation of multinucleated giant cells on day 7th. These giant cells were formed by round nuclei of early or late spermatids. In combination group (III), although germinal epithelium was still disorganized with loss of cells in few tubules, but no giant cell formation was observed. In order to know the mechanism of radioprotection of ginseng, LPO and GSH were estimated. It was observed that pretreated irradiated animals showed inhibition of LPO and increase in GSH. Thus the present study suggests ginseng protects male gonads. This may be attributed to the inhibition of LPO and increase synthesis of GSH byginseng.

  • PDF

홍삼박 n-hexane 추출물의 충치를 유발하는 Streptococcus mutans 저해 효과 (Inhibitory effect of n-hexane extract from Korean red ginseng marc against Streptococcus mutans causing dental caries)

  • 김동청;인만진
    • Journal of Applied Biological Chemistry
    • /
    • 제64권4호
    • /
    • pp.357-362
    • /
    • 2021
  • 본 연구에서는 홍삼의 항충치 효과를 조사하기 위하여 홍삼박 n-hexane 추출물의 충치 원인균 Streptococcus mutans에 대한 항균 효과, 균체 부착과 생물막 생성 저해 효과를 측정하였다. 홍삼박 n-hexane 추출물의 농도에 비례하여 S. mutans의 생육이 저해되었으며, 125 ㎍/mL 이상의 농도에서는 거의 관찰되지 않았다(MIC=125 ㎍/mL). 홍삼박 n-hexane 추출물이 세포막에 작용하여 세포의 핵산 성분이 유출시키는 것으로 나타났다. 그리고, 홍삼박 n-hexane 추출물은 125 ㎍/mL 이상의 농도에서 S. mutans의 부착과 생물막 형성을 90% 이상 저해하였다. GTase 활성은 50 ㎍/mL 농도에서 완전히 저해되었다. 결론적으로 홍삼박 n-hexane 추출물은 S. mutans의 생육과 생물막 형성을 공통적으로 저해하는 것으로 나타났다.

방사선 육종 차조기와 백출 복합물이 조골세포와 파골세포의 활성에 미치는 영향 (Effects of Perilla frutescens var. crispa and Atractylodes macrocephala Koidzumi mixture on Osteoblast Differentiation and Osteoclast Formation)

  • 심부용;지중구
    • 한국응용과학기술학회지
    • /
    • 제38권1호
    • /
    • pp.168-177
    • /
    • 2021
  • 본 연구는 방사선 육종 차조기와 백출 복합물의 조골세포 분화 활성 및 파골세포 형성 억제를 조사하였다. 차조기와 백출 복합물은 MG-63 세포에서 ALP 활성 및 arlizarin red 염색을 확인하였고 조골세포 형성의 영향은 RAW 264.7 세포에서 TRAP 활성과 TRAP 염색을 진행하였다. 세포 독성시험에서 차조기와 백출 복합물은 50 ㎍/㎖ 농도 이하에서 안전한 것으로 확인되었다. ALP 활성 및 골석회화 형성 능력은 대조군보다 활성이 낮았으나, 파골세포에서 TRAP 활성을 유의적으로 감소시켰으며, 효과적으로 TRAP(+) 다핵세포를 억제하였다. 따라서 차조기와 백출 복합물은 골 흡수 억제 활성을 향상시켜 뼈 관련 질환의 예방 및 치료에 효과적인 것으로 보여진다.

Cytokinin signaling promotes root secondary growth and bud formation in Panax ginseng

  • Kyoung Rok Geem;Yookyung Lim;Jeongeui Hong;Wonsil Bae;Jinsu Lee;Soeun Han;Jinsu Gil;Hyunwoo Cho;Hojin Ryu
    • Journal of Ginseng Research
    • /
    • 제48권2호
    • /
    • pp.220-228
    • /
    • 2024
  • Background: Panax ginseng, one of the valuable perennial medicinal plants, stores numerous pharmacological substrates in its storage roots. Given its perennial growth habit, organ regeneration occurs each year, and cambium stem cell activity is necessary for secondary growth and storage root formation. Cytokinin (CK) is a phytohormone involved in the maintenance of meristematic cells for the development of storage organs; however, its physiological role in storage-root secondary growth remains unknown. Methods: Exogenous CK was repeatedly applied to P. ginseng, and morphological and histological changes were observed. RNA-seq analysis was used to elucidate the transcriptional network of CK that regulates P. ginseng growth and development. The HISTIDINE KINASE 3 (PgHK3) and RESPONSE REGULATOR 2 (PgRR2) genes were cloned in P. ginseng and functionally analyzed in Arabidopsis as a two-component system involved in CK signaling. Results: Phenotypic and histological analyses showed that CK increased cambium activity and dormant axillary bud formation in P. ginseng, thus promoting storage-root secondary growth and bud formation. The evolutionarily conserved two-component signaling pathways in P. ginseng were sufficient to restore CK signaling in the Arabidopsis ahk2/3 double mutant and rescue its growth defects. Finally, RNA-seq analysis of CK-treated P. ginseng roots revealed that plant-type cell wall biogenesis-related genes are tightly connected with mitotic cell division, cytokinesis, and auxin signaling to regulate CK-mediated P. ginseng development. Conclusion: Overall, we identified the CK signaling-related two-component systems and their physiological role in P. ginseng. This scientific information has the potential to significantly improve the field-cultivation and biotechnology-based breeding of ginseng.

Production of homozygous klotho knockout porcine embryos cloned from genome-edited porcine fibroblasts

  • Lee, Sanghoon;Jung, Min Hee;Oh, Hyun Ju;Koo, Ok Jae;Park, Se Chang;Lee, Byeong Chun
    • 한국수정란이식학회지
    • /
    • 제31권3호
    • /
    • pp.179-183
    • /
    • 2016
  • Even though klotho deficiency in mice exhibits multiple aging-like phenotypes, studies using large animal models such as pigs, which have many similarities to humans, have been limited due to the absence of cell lines or animal models. The objective of this study was to generate homozygous klotho knockout porcine cell lines and cloned embryos. A CRISPR sgRNA specific for the klotho gene was designed and sgRNA (targeting exon 3 of klotho) and Cas9 RNPs were transfected into porcine fibroblasts. The transfected fibroblasts were then used for single cell colony formation and 9 single cell-derived colonies were established. In a T7 endonuclease I mutation assay, 5 colonies (#3, #4, #5, #7 and #9) were confirmed as mutated. These 5 colonies were subsequently analyzed by deep sequencing for determination of homozygous mutated colonies and 4 (#3, #4, #5 and #9) from 5 colonies contained homozygous modifications. Somatic cell nuclear transfer was performed to generate homozygous klotho knockout cloned embryos by using one homozygous mutation colony (#9); the cleavage and blastocyst formation rates were 72.0% and 8.3%, respectively. Two cloned embryos derived from a homozygous klotho knockout cell line (#9) were subjected to deep sequencing and they showed the same mutation pattern as the donor cell line. In conclusion, we produced homozygous klotho knockout porcine embryos cloned from genome-edited porcine fibroblasts.

식물배양세포(植物培養細胞)-Rhizobium에 의(依)한 질소고정(窒素固定)에 관한 연구 (Nitrogen fixation by Rhizobium-Plant cell cultures)

  • 박우철;곡전택도언
    • 한국토양비료학회지
    • /
    • 제12권1호
    • /
    • pp.43-46
    • /
    • 1979
  • 수년간(數年間) 계속배양(繼續培養)한 식물배양세포(植物培養細胞)와 근류균(根瘤菌)과의 질소고정(窒素固定)에서 그 mechanism을 알기 위(爲)하여 근류형성(根瘤形成) 및 감염과정(感染過程)을 알기 위(爲)해 연구하던 중 배양세포(培養細胞)에 단일균주(單一菌株) 및 혼합균주(混合菌株)의 접종(接種)에 의(依)한 Nitrogenase의 활성(活性)이 높은 것을 발견(發見)하였기에 그 차이(差異)를 조사(調査)한 결과(結果)는 다음과 같았다. 1. 단일접종(單一接種)에 있어서는 대두(大豆)에서의 Nitrogenase의 활성(活性)이 비(非)콩과 식물보다 대체적(大體的)으로 높았고, 혼합접종(混合接種)에 있어서는 비(非)콩과 식물에서 활성(活性)이 높았다. 2. 근류형성(根瘤形成) 및 Nitrogenase활성(活性)에 있어서의 특성(特性)인 host factor를 Callus에서는 대두중(大豆中) 북낭(北娘) 및 동양령(東洋鈴), 비(非)콩과 식물중에서는 Datura를 제외(除外)하고는 찾아볼 수가 없었다. 3. 균주별(菌株別)의 Nitrogenase활성(活性)은 비(非)콩과 식물에서는 012균주(菌株)가 콩과 식물인 대두(大豆)에서는 010, 023, 024균주(菌株)가 대체(大體)로 높았다.

  • PDF