711 research outputs found
Convergence of Scaled Delta Expansion: Anharmonic Oscillator
We prove that the linear delta expansion for energy eigenvalues of the
quantum mechanical anharmonic oscillator converges to the exact answer if the
order dependent trial frequency is chosen to scale with the order as
; as . It
converges also for , if , , where is the coupling constant in front of the operator .
The extreme case with , corresponds to the
choice discussed earlier by Seznec and Zinn-Justin and, more recently, by
Duncan and Jones.Comment: 37 pages (with 11 figures uuencoded at the end of the file,to be
stripped off), GEF-Th-7/199
Improved Convergence Proof of the Delta Expansion and Order Dependent Mappings
We improve and generalize in several accounts the recent rigorous proof of
convergence of delta expansion - order dependent mappings (variational
perturbation expansion) for the energy eigenvalues of anharmonic oscillator.
For the single-well anharmonic oscillator the uniformity of convergence in
is proven. The convergence proof is extended also to complex
values of lying on a wide domain of the Riemann surface of . Via the
scaling relation \`a la Symanzik, this proves the convergence of delta
expansion for the double well in the strong coupling regime (where the standard
perturbation series is non Borel summable), as well as for the complex ``energy
eigenvalues'' in certain metastable potentials. Sufficient conditions for the
convergence of delta expansion are summarized in the form of three theorems,
which should apply to a wide class of quantum mechanical and higher dimensional
field theoretic systems.Comment: some bugs of uuencoded postscript figures are fixe
The Systematic Method for Constructing the IDEA BANK Based on the EBL
This paper describes a method to construct IDEA BANK automatically. IDEA BANK is the data base of the "function-structure module" which is utilized in systematic conceptual design from Value Engineering perspectives. The method based on the Machine Learning EBL technique was evaluated and implemented for the IDEA BANK using SUN workstation. The practical implementation of the IDEA BANK acquisition was discussed after elucidating the problem and solution of the EBL technique in engineering design. In the IDEA BANK system, the structural features of an existing article are analyzed by hierarchically organized domain specific knowledge to yield a systematic explanation of how they function and attain their design goals. The explanation resulted in a generalized version of the Functional Diagram used in Value Engineering from which "function-structure module" can be extracted systematically
Multi-Physics Simulation Platform and Multi-Layer Metal Technology for CMOS-MEMS Accelerometer with Gold Proof Mass
This chapter describes technical features and solutions to realize a highly sensitive CMOS-MEMS accelerometer with gold proof mass. The multi-physics simulation platform for designing the CMOS-MEMS device has been developed to understand simultaneously both mechanical and electrical behaviors of MEMS stacked on LSI. MEMS accelerometer fabrication process is established by the multi-layer metal technology, which consists of the gold electroplating and the photo-sensitive polyimide film. The proposed MEMS accelerometers are fabricated and evaluated to verify the effectiveness of the proposed techniques regarding sub-1G MEMS and arrayed MEMS devices. The experimental results show that the Brownian noise of the sub-1G MEMS accelerometer can achieve 780 nG/(Hz)1/2 and the arrayed MEMS accelerometer has a wide detection, ranging from 1.0 to 20 G. Moreover, using the developed simulation platform, we demonstrate the proposed capacitive CMOS-MEMS accelerometer implemented by the multi-layer metal technology. In conclusion, it is confirmed that the multi-physics simulation platform and the multi-layer metal technology for the CMOS-MEMS device have a potential to realize a nano-gravity sensing technology
Psychological Stress-Induced Oxidative Stress as a Model of Sub-Healthy Condition and the Effect of TCM
Distress-mediated tissue oxidative stress was examined as a model of sub-healthy condition defined in traditional Chinese medicine theory. Mice were subjected to psychologically stressful conditions by whiskers removal. Under this condition, spontaneous locomotive activity was significantly enhanced in the dark (P < 0.05 versus the control mice in three different movements), and granulocytes/lymphocytes balance shifted to granulocytes. At the same time, peroxynitrite level in blood plasma increased to ∼180% from that of the control mice at 6 h after removal of the whiskers (P < 0.01), and was maintained even after 12 h. Both protein carbonyl formation and lipid peroxidation were significantly increased under this condition in brain, heart, liver and spleen at 6 h after removal of whiskers (P < 0.05 or P < 0.01), and these levels were maximized after 12 h (increased to 120–160%, P < 0.05 or P < 0.01). The oxidative tissue injuries observed at 12 h after the removal of the whiskers were effectively prevented by two traditional Chinese medicine formula: Shengmai San (SMS) and Ling Gui Zhu Gan Tang (LGZGT), when administered for 5 days before the removal of the whiskers. Therefore, this stress model is considered useful in assessing the preventive potential of antioxidants and antioxidant-based herbal mixtures in treating the pathophysiology associated with psychological or emotional distress
<Abstract of annual report>Mutagenicity of N-Nitrosodiethanolamine in the Salmonella/Microsome Test.
卵巣明細胞腺癌における転写因子HNF-1βはDNA損傷チェックポイント機構の一つであるCHK1タンパクを制御し、抗癌剤耐性を獲得する
Objective
Appropriate cell cycle checkpoints are essential for the maintenance of normal cells and chemosensitivity of cancer cells. Clear cell adenocarcinoma (CCA) of the ovary is highly resistant to chemotherapy. Hepatocyte nuclear factor-1β (HNF-1β) is known to be overexpressed in CCA, but its role and clinical significance is unclear. We investigated the role of HNF-1β in regulation of the cell cycle in CCA.
Methods
To clarify the effects of HNF-1β on cell cycle checkpoints, we compared the cell cycle distribution and the expression of key proteins involved in CCA cells in which HNF-1β had been stably knocked down and in vector-control cell lines after treatment with bleomycin. HNF-1β (+) cells were arrested in G2 phase because of DNA damage.
Results
HNF-1β (−) cells died because of a checkpoint mechanism. G2 arrest of HNF-1β (+) cells resulted from sustained CHK1 activation, a protein that plays a major role in the checkpoint mechanism. HNF-1β (+) cells were treated with a CHK1 inhibitor after bleomycin treatment. Flow cytometric analysis of the cell cycle demonstrated that DNA damage–induced G2-arrested cells were released from the checkpoint and killed by a CHK1 inhibitor.
Conclusions
The chemoresistance of CCA may be due to aberrant retention of the G2 checkpoint through overexpression of HNF-1β. This is the first study demonstrating cell cycle regulation and chemosensitization by a CHK1 inhibitor in CCA.博士(医学)・乙第1345号・平成26年12月3日© 2014 by the International Gynecologic Cancer Society and the European Society of Gynaecological Oncology
Crystallization and preliminary X-ray structural studies of human prouroguanylin. Corrigendum
A corrigendum to the article by Ito et al. [Acta Cryst. (2008). F64, 531–532]
Inhibition of ATR protein kinase activity by schisandrin B in DNA damage response
ATM and ATR protein kinases play a crucial role in cellular DNA damage responses. The inhibition of ATM and ATR can lead to the abolition of the function of cell cycle checkpoints. In this regard, it is expected that checkpoint inhibitors can serve as sensitizing agents for anti-cancer chemo/radiotherapy. Although several ATM inhibitors have been reported, there are no ATR-specific inhibitors currently available. Here, we report the inhibitory effect of schisandrin B (SchB), an active ingredient of Fructus schisandrae, on ATR activity in DNA damage response. SchB treatment significantly decreased the viability of A549 adenocarcinoma cells after UV exposure. Importantly, SchB treatment inhibited both the phosphorylation levels of ATM and ATR substrates, as well as the activity of the G2/M checkpoint in UV-exposed cells. The protein kinase activity of immunoaffinity-purified ATR was dose-dependently decreased by SchB in vitro (IC50: 7.25 μM), but the inhibitory effect was not observed in ATM, Chk1, PI3K, DNA-PK, and mTOR. The extent of UV-induced phosphorylation of p53 and Chk1 was markedly reduced by SchB in ATM-deficient but not siATR-treated cells. Taken together, our demonstration of the ability of SchB to inhibit ATR protein kinase activity following DNA damage in cells has clinical implications in anti-cancer therapy
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