• Journal of the korean society of oceanography
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• 제37권2호
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• pp.58-65
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• 2002

The study of microbial communities in sediments is impaired by the lack of reliable extraction methods. This study reports on the efficiency of recovery of a method for extracting bacteria, protists and diatoms from sandy sediments using a modified decant/fix method. The best extractions were achieved after fixation with a microtubule stabilising fixative and subsequent sonication for 80 seconds. We estimate that the efficiencies of recovery of bacteria and mixed heterotrophic flagellates were $96.4{\pm}3.5\%$ and $96.9{\pm}4.6\%$, respectively. Diatoms were recovered with an efficiency of 38-83% and varied considerably from species to species. This study suggests that the decant/fix method is effective in extracting small cells such as bacteria and heterotrophic flagellates, and that the efficiency of recovery of the method varies due to cell length and different types of organisms. When microbial carbon biomass had been underestimated by up to 32%, with much of that relating to larger cells such as microalgae and ciliates. We note that the corrected abundances may be still a subset of the total numbers present.

• 대한한방부인과학회지
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• 제28권2호
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• pp.1-14
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• 2015

Objectives : This study was designed to investigate the effects of Taraxaci Herba (TH) on cell death in breast cancer cells. Methods : In this experiment, the effects of TH on proliferation rates, cell morphology and growth pattern, intracellular reactive oxygen species (ROS) production. In addition, the effects on nuclear condensation, fragmentation and formation of acidic vesicular organelles (AVO) in MCF-7 cells were also investigated. Finally, autophagy related with protein was observed by using western blot method. Results : TH inhibited proliferation of MCF-7 cells, TH elevated intracellular ROS levels significantly. Treatment with TH did not affect nuclear morphologies such as condensation or fragmentation. On the other hand, TH treatment effectively induced AVO. Finally, one of autophagy related with protein, Microtubule-associated proteins 1A/1B light chain 3A (MAP1LC3A, LC3) level was elevated by treatment with TH. Conclusions : These data indicate that TH is able to be used for patient with breast cancer and mechanisms are involved in autophagy through ROS generation.

• Biomolecules & Therapeutics
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• 제22권5호
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• pp.384-389
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• 2014

Adiponectin, an adipokine predominantly secreted from adipose tissue, exhibits diverse biological responses, including metabolism of glucose and lipid, and apoptosis in cancer cells. Recently, adiponectin has been shown to modulate autophagy as well. While emerging evidence has demonstrated that autophagy plays a role in the modulation of proliferation and apoptosis of cancer cells, the role of autophagy in apoptosis of cancer cell caused by adiponectin has not been explored. In the present study, we demonstrated that globular adiponectin (gAcrp) induces both apoptosis and autophagy in human hepatoma cell line (HepG2 cells) and breast cancer cells (MCF-7), as evidenced by increase in caspase-3 activity, Bax, microtubule-associated protein light chain 3-II (LC3 II) protein levels, and autophagosome formation. Interestingly, gene silencing of LC3B, an autophagy marker, significantly enhanced gAcrp-induced apoptosis in both HepG2 and MCF-7 cell lines, whereas induction of autophagy by rapamycin, an mTOR inhibitor, significantly prevented gAcrp-induced apoptosis in hepatoma cells HepG2. Furthermore, modulation of autophagy produced similar effects on gAcrp-induced Bax expression in HepG2 cells. These results implicate that induction of autophagy plays a regulatory role in adiponectin-induced apoptosis of cancer cells, and thus inhibition of autophagy would be a novel promising target to enhance the efficiency of cancer cell apoptosis by adiponectin.

• Advances in concrete construction
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• 제9권5호
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• pp.491-501
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• 2020

Microtubules buckle under bending and torsion and this property has been studied for free microtubules before using orthotropic elastic shell model. But as microtubules are embedded in other elastic filaments and it is experimentally showed that these elastic filaments affect the critical buckling moment and critical buckling torque of the microtubules. To prove that, we developed orthotropic Winkler like model and demonstrated that the critical buckling moment and critical buckling torque of the microtubules are orders of higher magnitude than those found for free microtubules. Our results show that Critical buckling moment is about 6.04 nNnm for which the corresponding curvature is about θ = 1.33 rad /㎛ for embedded MTs, and critical buckling torque is 0.9 nNnm for the angle of 1.33 rad/㎛. Our results well proved the experimental findings.

• ALGAE
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• 제31권2호
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• pp.117-128
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• 2016

Cryptomonas curvata Ehrenberg is a photosynthetic freshwater flagellate and the type species of the genus Cryptomonas. We examined the flagellar apparatus of cryptomorphic C. curvata by transmission electron microscopy. The major components of the flagellar apparatus are the non-keeled rhizostyle (Rhs), striated fibrous root (SR), striated fiber-associated microtubular root (SRm), mitochondrion-associated lamella (ML), and two types of microtubular roots (3r and 2r). The non-keeled Rhs originate at the ventral basal body and consist of two types of microtubule bands extending together into the middle of the cell. The SR and SRm extend parallel to the left side of the cell. The ML originates from the ventral basal body and is a plate-like fibrous structure associated with mitochondria. The 3r extends from the dorsal basal body toward the dorsal anterior of the cell. The 2r originates between the two basal bodies and extends shortly to the left of the cell. The overall configuration of the flagellar apparatus is most similar to that previously reported for C. pyrenoidifera. These results demonstrate that the features of the flagellar apparatus are useful for distinguishing closely related species and inferring phylogenetic relationships among taxa.

• Asian Pacific Journal of Cancer Prevention
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• 제13권10호
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• pp.4867-4871
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• 2012

Cervical cancer is a leading cause of morbidity and mortality in women worldwide. Although the human papillomavirus (HPV) is considered the major causative agent of cervical cancer, yet the viral infection alone is not sufficient for cancer progression. The etiopathogenesis of cervical cancer is indeed complex; a precise understanding of the complex cellular/molecular mechanisms underlying the initiation, progression and/or prevention of the uterine cervix is therefore essential. Autophagy is emerging as an important biological mechanism in targeting human cancers, including cervical cancer. Furthermore, autophagy, a process of cytoplasm and cellular organelle degradation in lysosomes, has been implicated in homeostasis. Autophagic flux may vary depending on the cell/tissue type, thereby altering cell fate under stress conditions leading to cell survival and/or cell death. Autophagy may in turn govern tumor metastasis and subsequent carcinogenesis. Inflammation is a known hallmark of cancer. Vascular insufficiency in tumors, including cervical tissue, leads to depletion of glucose and/or oxygen perturbing the osmotic mileu causing extracellular acidosis in the tumor microenvironment that may eventually result in autophagy. Thus, targeted manipulation of complex autophagic signaling may prove to be an innovative strategy in identification of clinically relevant biomarkers in cervical cancer in the near future.

• Applied Microscopy
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• 제40권4호
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• pp.253-259
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• 2010

바다잉어과(Osmeridae)에 속하는 빙어(Hypomesus niponesis)의 정소 내 성숙한 정자들을 전자현미경을 이용하여 조사하였다. 빙어의 정소는 한 쌍으로 부레와 창자 사이에 위치하였고 좌측 정소가 우측 정소보다 큰 것으로 나타났으며 흰색이었다. 정소 내의 성숙한 정자의 길이는 $26{\mu}m$ 정도였다. 두부는 난형으로 직경은 400 nm 정도였으며 첨체는 관찰되지 않았고, 특히 염색질의 이질적 응축이 관찰되었다. 두부의 핵이 함입되어 핵와(nuclear fossa)가 깊게 형성되었으며 핵와 내 기저부에서 편모가 직선으로 분포하였고 편모의 미세소관은 전형적인 9+2 구조를 이루고 있었다. 또한 편모의 외측에는 두개의 axonemal fin이 관찰되었으며, 중편에는 미토콘드리아가 하나만 존재하였다.

• 미생물학회지
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• 제35권1호
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• pp.18-24
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• 1999

Kinesin은 Saccharomyces cerevisiae, Aspergillus nidulans, Drosophila melanogaster 등에서 발견 되었으며 dynein 과 더불어 세포분열 과정중 chromosome 의 이동과 spindle pole 의 분리에 관련된 것으로 알려져 있다. 본 연구에서는 기존에 발견된 kinesin 유사 유전자의 homology 가 많은 motor domain을 이용하여 primer를 합성한 후 이를 이용하여 Schizosaccharomyces pombe 로부터 kinesin heavy chain 의 유전자를 클론하였다. 염기서열을 결정한 결과 2496 bp의 해독틀을 가지고 있으며 832개의 아미노산으로 이루어진 분자량이 96 kd의 kinesin heavy chain을 암호화하는 것이 밝혀졌다. 기존에 밝혀진 다른 organism 의 kinesin 과 서열을 비교한 결과 새로이 클론된 S.pombe 의 kinesin 은 C-terminal motor subfamily 에 속함이 밝혀졌다.

• Applied Microscopy
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• 제21권1호
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• pp.46-62
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• 1991

The intermediate filament is one of the most important constituents of the intracytoplasmic cytoskeleton microtubule, actin, myosin and intermediate filament. It is composed of keratin, desmin, vimentin, neurofilament and glial filament, and has important role as a cellular marker, epithelial or mesenchymal origin. So it will be important to differentiated from some poorly or undifferentiated neoplasm to provide adequate therapeutic modalities. This study was performed by using immunohistochemical staining and electron microscopic observation to find out intermediate filaments of epithelial and non-epithelial tumor cells evaluate the degree of differentiation in tumors and therefore to provide some diagnostic and therapeutic modalities. The materials consisted of 83 epithelial and non-epithelial elements bearing 23 normal control, 28 epithelial tumors, and 32 non-epithelial tumors, that are resected for definite treatment at Chosun University Hospital from June, 1988 to June, 1990. Immunohistochemical stain for keratin, desmin and vimentin, and electron microscopic study were performed in all cases. The results obtained were as follows. 1. Immunohistochemical stain for intermediate filament were very useful diagnostic aid for differentiated epithelial tumor to non-epithelial tumor in diagnostic neoplasia. 2. In the electron microscopic finding, the size of intermediate filaments were possible differentiated to cell components of epithelial tumor and non-epithelial tumors.

• Genomics & Informatics
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• 제17권3호
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• pp.27.1-27.9
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• 2019

Supernumerary B chromosomes were found in Lilium amabile (2n = 2x = 24), an endemic Korean lily that grows in the wild throughout the Korean Peninsula. The extra B chromosomes do not affect the host-plant morphology; therefore, whole transcriptome analysis was performed in 0B and 1B plants to identify differentially expressed genes. A total of 154,810 transcripts were obtained from over 10 Gbp data by de novo assembly. By mapping the raw reads to the de novo transcripts, we identified 7,852 differentially expressed genes (log₂FC > |10|), in which 4,059 and 3,794 were up-and down-regulated, respectively, in 1B plants compared to 0B plants. Functional enrichment analysis revealed that various differentially expressed genes were involved in cellular processes including the cell cycle, chromosome breakage and repair, and microtubule formation; all of which may be related to the occurrence and maintenance of B chromosomes. Our data provide insight into transcriptomic changes and evolution of plant B chromosomes and deliver an informative database for future study of B chromosome transcriptomes in the Korean lily.