• 제목/요약/키워드: tor

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출구 릴레이 방법론을 이용한 Tor 보안 정책 (A Tor Security Policy using Exit Relay Methodology)

  • 장덕성;박소연;최두영
    • 한국멀티미디어학회논문지
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    • 제20권6호
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    • pp.911-917
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    • 2017
  • Tor proxy tool is studied which is most frequently used for ransomeware to penetrate into sensitive information. It will be researched for the malicious methods to spread virus by using Tor and considered a countermeasure to prevent them. We present exit relay methodology for Tor security policy, simulate it, and get a probability to detect the ransomeware. And we compare it with TSS technology which is able to protect the attack via virtual server on exit relay.

Mammalian target of rapamycin inhibitors for treatment in tuberous sclerosis

  • Kim, Won-Seop
    • Clinical and Experimental Pediatrics
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    • 제54권6호
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    • pp.241-245
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    • 2011
  • Tuberous sclerosis complex (TSC) is a genetic multisystem disorder that results from mutations in the TSC1 or TSC2 genes, and is associated with hamartomas in several organs, including subependymal giant cell tumors. The neurological manifestations of TSC are particularly challenging and include infantile spasms, intractable epilepsy, cognitive disabilities, and autism. The TSC1- and TSC2-encoded proteins modulate cell function via the mammalian target of rapamycin (mTOR) signaling cascade, and are key factors in the regulation of cell growth and proliferation. The mTOR pathway provides an intersection for an intricate network of protein cascades that respond to cellular nutrition, energy levels, and growth factor stimulation. In the brain, TSC1 and TSC2 have been implicated in cell body size, dendritic arborization, axonal outgrowth and targeting, neuronal migration, cortical lamination, and spine formation. The mTOR pathway represents a logical candidate for drug targeting, because mTOR regulates multiple cellular functions that may contribute to epileptogenesis, including protein synthesis, cell growth and proliferation, and synaptic plasticity. Antagonism of the mTOR pathway with rapamycin and related compounds may provide new therapeutic options for TSC patients.

MiR-99a Inhibits Cell Proliferation and Tumorigenesis through Targeting mTOR in Human Anaplastic Thyroid Cancer

  • Huang, Hou-Gang;Luo, Xi;Wu, Shuai;Jian, Bin
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권12호
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    • pp.4937-4944
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    • 2015
  • MicroRNAs (miRNAs) are emerging as critical regulators in carcinogenesis and tumor progression. Recently, miR-99a has been reported as a tumor suppressor gene in various human cancers, but its functions in the context of anaplastic thyroid cancer (ATC) remain unknown. In this study, we reported that miR-99a was commonly downregulated in ATC tissue specimens and cell lines with important functional consequences. Overexpression of miR-99a not only dramatically reduced ATC cell viability by inducing cell apoptosis and accumulation of cells at G1 phase, but also inhibited tumorigenicity in vivo. We then screened and identified a novel miR-99a target, mammalian target of rapamycin (mTOR), and it was further confirmed by luciferase assay. Up-regulation of miR-99a would markedly reduce the expression of mTOR and its downstream phosphorylated proteins (p-4E-BP1 and p-S6K1). Similar to restoring miR-99a expression, mTOR down-regulation suppressed cell viability and increased cell apoptosis, whereas restoration of mTOR expression significantly reversed the miR-99a antitumor activity and the inhibition of mTOR/p-4E-BP1/p-S6K1 signal pathway profile. In clinical specimens and cell lines, mTOR was commonly overexpressed and its protein levels were statistically inversely correlated with miR-99a expression. Taken together, our results demonstrated for the first time that miR-99a functions as a tumor suppressor and plays an important role in inhibiting the tumorigenesis through targeting the mTOR/p-4E-BP1/p-S6K1 pathway in ATC cells. Given these, miR-99a may serve as a novel prognostic/diagnostic and therapeutic target for treating ATC.

New Insights into mTOR Signal Pathways in Ovarian-Related Diseases: Polycystic Ovary Syndrome and Ovarian Cancer

  • Liu, Ai Ling;Liao, Hong Qing;Li, Zhi Liang;Liu, Jun;Zhou, Cui Lan;Guo, Zi Fen;Xie, Hong Yan;Peng, Cui Ying
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권12호
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    • pp.5087-5094
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    • 2016
  • mTOR, the mammalian target of rapamycin, is a conserved serine/threonine kinase which belongs to the phosphatidyl-linositol kinase-related kinase (PIKK) family. It has two complexes called mTORC1 and mTORC2. It is well established that mTOR plays important roles in cell growth, proliferation and differentiation. Over-activation of the mTOR pathway is considered to have a relationship with the development of many types of diseases, including polycystic ovary syndrome (PCOS) and ovarian cancer (OC). mTOR pathway inhibitors, such as rapamycin and its derivatives, can directly or indirectly treat or relieve the symptoms of patients suffering from PCOS or OC. Moreover, mTOR inhibitors in combination with other chemical-molecular agents may have extraordinary efficacy. This paper will discuss links between mTOR signaling and PCOS and OC, and explore the mechanisms of mTOR inhibitors in treating these two diseases, with conclusions regarding the most effective therapeutic approaches.

Rapamycin-Induced Abundance Changes in the Proteome of Budding Yeast

  • Shin, Chun-Shik;Chang, Yeon-Ji;Lee, Hun-Goo;Huh, Won-Ki
    • Genomics & Informatics
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    • 제7권4호
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    • pp.203-207
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    • 2009
  • The target of rapamycin (TOR) signaling pathway conserved from yeast to human plays critical roles in regulation of eukaryotic cell growth. It has been shown that TOR pathway is involved in several cellular processes, including ribosome biogenesis, nutrient response, autophagy and aging. However, due to the functional diversity of TOR pathway, we do not know yet some key effectors of the pathway. To find unknown effectors of TOR signaling pathway, we took advantage of a green fluorescent protein (GFP)-tagged collection of budding yeast Saccharomyces cerevisiae. We analyzed protein abundance changes by measuring the GFP fluorescence intensity of 4156 GFP-tagged yeast strains under inhibition of TOR pathway. Our proteomic analysis argues that 83 proteins are decreased whereas 32 proteins are increased by treatment of rapamycin, a specific inhibitor of TOR complex 1 (TORC1). We found that, among the 115 proteins that show significant changes in protein abundance under rapamycin treatment, 37 proteins also show expression changes in the mRNA levels by more than 2-fold under the same condition. We suggest that the 115 proteins indentified in this study may be directly or indirectly involved in TOR signaling and can serve as candidates for further investigation of the effectors of TOR pathway.

다수의 가상머신을 이용한 토르 트래픽 수집 시스템 설계 및 구현 (Design and Implementation of Tor Traffic Collection System Using Multiple Virtual Machines)

  • 최현재;김현수;신동명
    • 한국소프트웨어감정평가학회 논문지
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    • 제15권1호
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    • pp.1-9
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    • 2019
  • 본 논문에서는 사용자 및 서비스 제공자의 신원을 공개하지 않는 토르 네트워크상에서 불법적으로 콘텐츠를 공유하는 행위의 저작권 침해를 탐지하기 위하여 트래픽을 효율적으로 수집하고 분석하고자, 다수의 가상머신을 이용한 토르 트래픽 수집 시스템 설계 및 구현을 진행하였다. 토르 네트워크에 접속할 수 있는 클라이언트로 다수의 가상머신과 Mini PC를 이용하였으며, 스크립트 기반의 테스트 클라이언트 소프트웨어를 통해 트래픽 수집 서버에서 수집과 정제 과정을 모두 자동화하였다. 이 시스템을 통해 토르 네트워크 트래픽만을 저장하고 필요한 필드 데이터만을 데이터베이스에 저장할 수 있으며, 한 번의 수집 과정 당 평균적으로 약 10,000개 이상의 패킷을 데이터베이스에 저장하고 토르 트래픽만을 인식하여 정제하는 성능을 95% 이상 달성하였다.

MCF-7 유방암 세포에서 mTOR-COX-2 신호경로를 통한 resveratrol의 apoptosis 효과 (Apoptotic Effects of Resveratrol via mTOR and COX-2 Signal Pathways in MCF-7 Breast Cancer Cells)

  • 이솔화;이혜연;박송이;박옥진;김영민
    • 생명과학회지
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    • 제21권9호
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    • pp.1288-1294
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    • 2011
  • 식물에서 추출한 파이토케미컬은 암세포의 여러 신호전달 기작에 관여함으로써 apoptosis를 유도한다. 본 연구에서는 파이토케미컬의 한 종류인 레스베라트롤을 MCF-7 세포에 처리함으로써 암세포의 증식 억제와 apoptosis 유도 효과를 알아보았고, 이러한 효과가 암세포의 성장과 증식에 관여하는 단백질인 mTOR와 COX-2의 발현 양상에 어떠한 영향을 미치는지 알아보고자 하였다. 그 결과 MCF-7 세포에 레스베라트롤을 처리했을 때 농도가 증가함에 따라 암세포의 생존률이 감소하였고, Hoechst 33342를 이용한 chromatin 염색과 Annexin V-propodium iodide staning을 통하여 암세포의 세포증식 효과가 apoptosis에 의해 유도된 것임을 알 수 있었다. MCF-7 세포에 레스베라트롤을 처리했을 때 mTOR 및 COX-2의 발현 양상을 확인하기 위해 Western blotting을 실시한 결과, 레스베라트롤의 농도가 높아짐에 따라 mTOR 및 COX-2의 발현이 감소함을 확인 하였다. 이와 같은 결과는 MCF-7 유방암 세포에서 레스베라트롤에 의한 암세포의 증식 억제 및 apoptosis 유도가 mTOR 신호경로 저해를 통한 COX-2의 발현을 감소시킴으로써 나타나는 것으로 보인다.

자율주행 차량의 제어권 인수요구 정보양상과 도로 형태에 따른 운전자의 제어권 인수시간과 정신적 작업부하 차이 (The Effects of Control Takeover Request Modality of Automated Vehicle and Road Type on Driver's Takeover Time and Mental Workload)

  • 윤남경;이재식
    • 감성과학
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    • 제26권4호
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    • pp.51-70
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    • 2023
  • 본 연구에서는 운전 시뮬레이션을 사용하여 자율주행 환경을 구현한 후 3-수준 자율주행 조건에서 자율주행 차량 (automated vehicle: AV)으로부터 운전자에게 전달되는 제어권 인수 요구(takeover request: TOR) 정보의 양상(시각, 청각 및 시각+청각) 및 도로 형태(직선도로와 곡선도로)에 따라 운전자의 제어권 인수 시간(takeover time: TOT) 및 정신적 작업부하(제어권 인수 이후에 운전자들이 경험한 주관적 작업부하와 심장박동수에서의 변화)가 어떻게 차별화되는지 분석하였다. 본 연구의 결과를 요약하면 다음과 같다. 먼저, AV로부터 TOR이 제시된 이후 실험참가자들이 보인 TOT에 대한 분석 결과, TOR 정보양상의 측면에서는 시각 정보가 가장 빠른 TOT를 이끌어 낸 반면 청각정보 조건에서 가장 느렸고, 도로 형태 측면에서는 직선도로 조건에 비해 곡선도로 조건에서의 TOT가 유의하게 더 느렸으며, 특히 청각 정보 조건에서 도로 형태에 따른 TOT에서의 차이가 가장 컸다. 둘째, 정신적 작업부하에 대한 분석 결과, TOR 정보가 시각 혹은 시각+청각적으로 제시된 조건에 비해 청각적으로 제시된 조건에서 주관적 작업부하 측정치와 심장박동수 변화 크기 모두 전반적으로 더 낮았고 특히, 심장박동수 변화의 경우 이러한 경향은 곡선도로 조건에서만 관찰되었다. 이러한 결과는 TOR 정보의 양상과 도로 형태에 따라 운전자의 TOT와 정신적 작업부하 수준이 달라질 수 있고, 특히 TOT가 빠를수록 정신적 작업부하 수준은 상대적으로 더 높아질 수 있음을 시사한다.

생쥐 착상전 배아의 인슐린 신호전달 과정에 Phosphatidylinositol 3-Kinase의 관련성 (Involvement of Phosphatidylinositol 3-Kinase in the Insulin Signaling in Preimplantation Mouse Embryos)

  • Gye, Myung-Chan;Nah, Hee-Young;Kim, Moon-Kyoo
    • 한국발생생물학회지:발생과생식
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    • 제4권1호
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    • pp.29-35
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    • 2000
  • A phosphatidylinositol 3-kinase (PI3K)는 인슐린 신호전달의 상위구성 요소로 다양한 세포에서 단백질합성을 촉진한다. PI3K와 하위의 mammalian target of rapamycin (mTOR)가 착상전 생쥐 배아의 인슐린 신호전달에 관여하고 있는지의 여부를 조사하고자 하였다. 생쥐의 8-세포기 배아를 인슐린 또는 PI3K및 mTOR의 억제제를 포함한 조건에서 배양하면서 발생율, 할구수, 단백질합성 및 인산화를 조사하였다. 인슐린의 첨가는 포배형성과 부화 등 형태발생을 촉진하며 포배내 평균 할구수, 8-세포기 배아의 단백질 합성과 인산화를 유의하게 증가시켰다. PI3K의 억제제인 wortmannin과 mTOR를 억제하는 rapamycin은 인슐린에 의한 발생율, 포배내, 할구수, 단백질합성의 증가 효과를 상쇄하였다. 오토라디오그라피에서 두종의 인산화단백질인 pp22와 pp30의 인산화가 인슐린 처리에 의해 증가함을 확인하였다. 이상의 결과에서 생쥐 8-세포기 배아의 발생을 촉진하는 인슬린 신호의 전달에 PI3K와 mTOR가 관여함을 알 수 있다.

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Prevalence and Clinical Significance of Mammalian Target of Rapamycin Phosphorylation (p-mTOR) and Vascular Endothelial Growth Factor (VEGF) in Clear Cell Carcinoma of the Ovary

  • Khemapech, Nipon;Pitchaiprasert, Sunaree;Triratanachat, Surang
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권12호
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    • pp.6357-6362
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    • 2012
  • Background: To determine the prevalence of mammalian target of rapamycin phosphorylation (p-mTOR) and vascular endothelial growth factor (VEGF) and any correlation with clinical characteristics and prognosis in ovarian clear cell carcinoma patients. Materials and Method: Seventy four paraffin-embedded specimens of such carcinomas frompatients who underwent surgery, received adjuvant chemotherapy and were followed up at King Chulalongkorn Memorial Hospital during January 2002 to December 2008 were stained with rabbit monoclonal IgG p-mTOR and rabbit polyclonal IgG VEGF using immunohistochemical methods. Medical records were reviewed and clinical variables were analysed. Results: The prevalence of positive p-mTOR in ovarian clear cell carcinoma was 87.9% and significantly higher in advance-stage than early-stage patients (100% versus 83.6%, P<0.05). Two-year disease free survival and 2-year overall survival in patients with positive p-mTOR expression were 60% and 69.2% with no differences from patients with negative p-mTOR expression (p>0.05). The prevalence of VEGF expression was 63.5% and significantly higher in chemo-sensitive than chemo-resistant patients (70.7% versus 37.5%, P<0.05). Two-year disease free survival and 2-year overall survival in patients with VEGF expression were 72.3% and 83% respectively which were significantly different from patients with negative VEGF expression (p<0.05). Conclusions: p-mTOR expression in ovarian clear cell carcinoma was significantly correlated with the stage of disease. VEGF expression was significantly correlated with chemosensitivity, and survival. Further studies of related targeted therapy might be promising.