• Title/Summary/Keyword: delta derivative

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Effect of a (S)-(+)-decursin Derivative, (S)-(+)-3-(3,4-dihydroxy-phenyl)-acrylic Acid 2,2-dimethyl-8-oxo-3,4-dihydro-2H,8H-pyrano[3,2-g]-chromen-3-yl-ester on Apoptosis of Eosinophils and Neutrophils in Normal and Asthmatic Subjects

  • Kim, In-Sik;Yang, Eun-Ju;Lee, Ji-Sook
    • Biomedical Science Letters
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    • v.18 no.3
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    • pp.307-309
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    • 2012
  • (S)-(+)-3(3,4-dihydroxy-phenyl)-acrylic acid 2,2-dimethyl-8-oxo3,4-dihydro-2H,8H-pyrano[3,2-g]Chromen-3-yl-ester (Compound 6, C6) is synthesized from (S)-(+)-decursin and attenuates the pathophysiologic progression of asthma in a ovalbumin-induced asthmatic mouse model. In the present study, we examined the effect of C6 on spontaneous apoptosis of eosinophils and neutrophils of normal and asthmatic subjects. C6 increased the apoptosis of asthmatic eosinophils in a dose-dependent manner, but it inhibited neutrophil apoptosis. C6 has no effect on apoptosis of normal eosinophils and neutrophils. LY294002, an inhibitor of PI3K, rottlerin, an inhibitor of $PKC{\delta}$, Ro-31-8425, an inhibitor of classical PKC inhibitor, PD98059, an inhibitor of MEK, and BAY 11-7085, an inhibitor of NF-${\kappa}B$, blocked the inhibitory effect on apoptosis of asthmatic neutrophils due to C6. These results indicate that C6 may be valuable as a therapeutic agent for the treatment of asthma.

Self-assembly and Mechanism of L-Alanine-based Dihydrazide Derivative as Excellent Gelator of Organic Solvents

  • Wang, Chuan-Sheng;Wang, Xiao-Hong;Li, Zhi-Yuan;Wei, Wei;Shi, Zhong-Liang;Sui, Zhi-Tong
    • Bulletin of the Korean Chemical Society
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    • v.32 no.4
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    • pp.1258-1262
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    • 2011
  • A new organogelator, L-Alanine dihydrazide derivative can self-assemble in various organic solvents and turned them into thermally reversible physical supramolecular organogels at extremely low concentrations (< 2 wt %). The gel-sol phase transition temperatures ($T_{GS}$) were determined as a function of gelator concentration and the corresponding enthalpies (${\Delta}H_g$) were extracted. Scanning electron microscopy (SEM) measurements revealed that the interspaces of fiber-like network structures were diminished with the increasing of the LMOG concentration. FT-IR spectroscopy studies revealed that hydrogen-bonding and hydrophobic interaction were the driving forces for the formation of the gels. Based on the data of XRD and molecular modeling, the possible packing modes for the formation of organogelator aggregates were proposed.

Sensorless Detection of Position and Speed in Brushless DC Motors using the Derivative of Terminal Phase Voltages Technique with a Simple and Versatile Motor Driver Implementation

  • Carlos Gamazo Real, Jose;Jaime Gomez, Gil
    • Journal of Electrical Engineering and Technology
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    • v.10 no.4
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    • pp.1540-1551
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    • 2015
  • The detection of position and speed in BLDC motors without using position sensors has meant many efforts for the last decades. The aim of this paper is to develop a sensorless technique for detecting the position and speed of BLDC motors, and to overcome the drawbacks of position sensor-based methods by improving the performance of traditional approaches oriented to motor phase voltage sensing. The position and speed information is obtained by computing the derivative of the terminal phase voltages regarding to a virtual neutral point. For starting-up the motor and implementing the algorithms of the detection technique, a FPGA board with a real-time processor is used. Also, a versatile hardware has been developed for driving BLDC motors through pulse width modulation (PWM) signals. Delta and wye winding motors have been considered for evaluating the performance of the designed hardware and software, and tests with and without load are performed. Experimental results for validating the detection technique were attained in the range 5-1500 rpm and 5-150 rpm under no-load and full-load conditions, respectively. Specifically, speed and position square errors lower than 3 rpm and between 10º-30º were obtained without load. In addition, the speed and position errors after full-load tests were around 1 rpm and between 10º-15º, respectively. These results provide the evidence that the developed technique allows to detect the position and speed of BLDC motors with low accuracy errors at starting-up and over a wide speed range, and reduce the influence of noise in position sensing, which suggest that it can be satisfactorily used as a reliable alternative to position sensors in precision applications.

Variation of activation functions for accelerating the learning speed of the multilayer neural network (다층 구조 신경회로망의 학습 속도 향상을 위한 활성화 함수의 변화)

  • Lee, Byung-Do;Lee, Min-Ho
    • Journal of Sensor Science and Technology
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    • v.8 no.1
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    • pp.45-52
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    • 1999
  • In this raper, an enhanced learning method is proposed for improving the learning speed of the error back propagation learning algorithm. In order to cope with the premature saturation phenomenon at the initial learning stage, a variation scheme of active functions is introduced by using higher order functions, which does not need much increase of computation load. It naturally changes the learning rate of inter-connection weights to a large value as the derivative of sigmoid function abnormally decrease to a small value during the learning epoch. Also, we suggest the hybrid learning method incorporated the proposed method with the momentum training algorithm. Computer simulation results show that the proposed learning algorithm outperforms the conventional methods such as momentum and delta-bar-delta algorithms.

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GC/MS Analysis of Volatile Constituents from Acanthopanax senticosus (가시오갈피나무의 정유성분 GC/MS 분석)

  • Lim, Soon-Sung;Lee, Jeong-Min;Park, Hee-Seung;Cho, Seon-Haeng;Shin, Kuk-Hyun;Lee, Sang-Hyun
    • Korean Journal of Pharmacognosy
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    • v.38 no.4
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    • pp.327-333
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    • 2007
  • The chemical composition of the volatile constituents from the leaves, stems, and roots of Acanthopanax senticosus growing wild in Mt. Deok-Yu was determined by GC and GC/MS spectrometric analysis with the aid of NBS, Wiley Library and RI indice searches. The major constituents identified were ${\delta}-elemene\;(23.14%),\;{\beta}-elemene\;(5.59%),\;{\gamma}-cadinene\;(5.43%),\;and\;{\alpha}-bergamotene\;(28.54%)$ in the leaves, ${\alpha}-pinene\;(11.50%),\;{\delta}-elemene\;(17.62%),\;{\alpha}-bergamotene\;(27.21%)$, and bicycloheptane derivative (6.38%) in the stems, and ${\alpha}-pinene\;(21.90%)$, and (+)-aromadendrene (3.77%) in the roots.

Extractive fermentation of Monascus purpureus promotes the production of oxidized congeners of the pigment azaphilone

  • Lim, Yoon Ji;Lee, Doh Won;Park, Si-Hyung;Kwon, Hyung-Jin
    • Journal of Applied Biological Chemistry
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    • v.61 no.4
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    • pp.327-334
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    • 2018
  • Monascus is a source of food colorant with high productivity of the pigment azaphilone. Monascus azaphilone (MAz) is biosynthesized through a single non-reducing polyketide pathway, the major components of which are ankaflavin (1), monascin (2), rubropunctatin (3) and monascorubrin (4); valuable biological activities have been reported for these compounds. Thus, various culture conditions were explored to reduce the cost of culture ingredients, enhance productivity and modulate compound composition. In the present study, we examined an extractive fermentation (EF) method with Diaion HP-20 resin (HP20) in direct comparison to a previously explored method involving Triton X-100 (TX100) to explore the modulated production of the major MAzs. We employed wild-type Monascus purpureus as well as two derivative recombinant strains (${\Delta}mppG$ and ${\Delta}mppE$) that are known to have differential MAz profiles as that of the wild-type strain. The HP20 resin was capable of modulating the MAz profile in favor of orange MAzs 3 and 4, oxidized congeners in this class, as was TX100-a phenomenon not previously observed for TX100 EF with Monascus anka. These finding substantiate that HP20 can be employed for the selective production of oxidized MAz and for diversifying the culture conditions used for Az production.

Lack of Prognostic Value of Mean Corpuscular Volume with Capecitabine Therapy in Metastatic Breast Cancer

  • Bozkurt, Oktay;Berk, Veli;Kaplan, Muhammed Ali;Cetin, Bulent;Ozaslan, Ersin;Karaca, Halit;Inanc, Mevlude;Duran, Ayse Ocak;Ozkan, Metin
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.6
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    • pp.2501-2504
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    • 2014
  • Background: Capecitabine is an oral fluoropyrimidine derivative which is frequently used alone or in combination regimens for the treatment of metastatic breast cancer. Although overall and progression free survivals have increased in recent years with the use of new generation drugs, predictive factors that would further improve the outcomes are needed. Previous studies have demonstrated the relation between post-treatment increase in mean corpuscular volume (MCV) and predicting therapy response as well as survival. The present study investigated the clinical impact of MCV elevation in metastatic breast cancer patients treated with capecitabine. Materials and Methods: The data of a total of 82 patients from three centers followed between June 2005 and June 2013 were retrospectively analyzed. The demographic data and hormone receptor status of the patients, as well as initial examination before and after treatment and data concerning progression were recorded. MCV ${\geq}100$ fl was considered as macrocytosis. Capecitabine was given at a dose of $2500mg/m^2$ daily for 14 days every three weeks. Pre-treatment and post-treatment MCV and other parameters of complete blood count were recorded. Post-treatment initial evaluation was performed after 2 cycles of therapy. Results: The median age of the patients was 46.5 years (range 26-72 years) and 54% were premenopausal. Performance status was ECOG 0 and 1 in 81 (99%) patients. The median number of cycles for capecitabine therapy was 5 (min-max: 2-18). The median ${\Delta}MCV$ level (post-treatment values at sixth week - baseline) was 6.4. Whilst ${\Delta}MCV$ was ${\geq}6.4$ in 42 patients, it was <6.4 in 40 patients. Clinical benefit (complete response+partial response+stable disease) was observed in 37 (88%) of 42 patients with a median ${\Delta}MCV$ ${\geq}6.4$ and in 30 (75%) of 40 patients with ${\Delta}MCV$ <6.4 with no statistically significant difference (p=0.158). No significant difference was determined between the group with ${\Delta}MCV$ ${\geq}6.4$ and the group with ${\Delta}MCV$ <6.4 in terms of progression-free survival (11 vs 12 months) (p=0.55) and overall survival (20 months vs. 24 months) (p=0.11). Conclusions: The identification of new predictive markers in metastatic breast cancer is very important. In some recent studies, increase in MCV has been suggested as a marker in tumor response. In the present study, however, no significant difference was determined between tumor response and increase in MCV. Further studies including higher numbers of patients are needed to determine whether increase in MCV is a predictive marker or not.

Measurement of Cardiac Function using Impedance Cardiography (임피던스 심장기록법을 이용한 심장기능의 측정)

  • 김덕원;김정열
    • Journal of Biomedical Engineering Research
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    • v.9 no.1
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    • pp.109-116
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    • 1988
  • In this paper, principles of impedance tenchinque and relationship between stroke volume and impedance change were theoretically explained. An impedance cardiograph was designed and constructed. Its reproducibility was verified by experiment. Until now, the peak point of dZ/dt waveform, first derivative of impedance change(${\Delta}$Z) , has been detected by software technique requiring considerable time to process. However in this paper its peak point was found using hardware for saving processing time. Useful cardiac parameters such as stroke volume and contractility of cardiac muscle were measured noninvasively. The reproducibility of the instrument was measured to be better(less than 10%) than that of clinical standard method such as thermodilution (more than 30%). Hence impedance cardiography was found to be better techique for monitoring stroke volume and myocardial contractility for pre and post operation, and pharmacological studies.

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Theory of Thin Sample z-scan of a New Class of Nonlinear Materials

  • Kim, Yong-K.
    • KIEE International Transactions on Electrophysics and Applications
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    • v.3C no.6
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    • pp.246-251
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    • 2003
  • We report the theory of thin-sample Z -scan for materials, viz. diffusion-dominated photorefractives, having a nonlinearly induced phase that may be proportional to the spatial derivative of the intensity profile. The on-axis far-field intensity is approximately an even function of the scan distance on different positive and negative values for phase shift $\Delta$$\Phi$$_{o}$. In case of positive phase shift, the Z -scan graph shows a minimum and two maxima, while for the negative value, only one minimum is observed. The fact is that far-field beam profiles display beam distortion and shift of the peak as compared with Kerr-type or photovoltaic nonlinearities.s.

A Novel Chenodeoxycholic Derivative HS-1200 Induces Apoptosis in Human HT-29 Colon Cancer Cells (인체 대장암 세포주(HT-29)에서 담즙산 합성유도체(HS-1200)의 세포 사망 기전)

  • Oh Sin Geun;Yang Kwang Mo;Hur Won Joo;Yoo Young Hyun;Suh Hong Suk;Lee Hyung Sik
    • Radiation Oncology Journal
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    • v.20 no.4
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    • pp.367-374
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    • 2002
  • Purpose : To investigate the growth inhibitory effects, and the underlying mechanism of human colon cancer cell (HT-29) death, induced by a new synthetic bile acid derivative (HS-1200). Materials and Methods : Human colon cancer cells (HT-29), in exponential growth phase, were treated with various concentrations of a new synthetic bile acid derivative (HS-1200). The growth inhibitory effects on HT-29 cells were examined using a frypan blue exclusion assay. The extent of apoptosis was determined using agarose gel electrophoresis, TUNEL assays and Hoechst staining. The apoptotic cell death was also confirmed by Western blotting of PARP, caspase-3 and DNA fragmentation factor (DFF) analysis. To investigate the involvement of mitochondria, we employed immunofluorescent staining of cytochrome c and mitochondrial membrane potential analyses. Results : The dose required for the half maximal inhibition $(IC_{50})$ of the HT-29 cell growth was $100\~150\;{\mu}M$ of HS-1200. Several changes, associated with the apoptosis of the HT-29 cells, were reveal by the agarose gel eletrophoresis, TUNEL assays and Hoechst staining, following their treatment with $100\;{\mu}M$ of HS-1200. HS-1200 treatment also induced caspase-3, PARP and DFF degradations, and the western blotting showed the processed caspase-3 p20, PARP p85 and DFF p30 and p11 cleaved products. Mitochondrial events were also demonstrated. The cytochrome c staining indicated that cytochrome c had been released from the mitochondria in the HS-1200 treated cells. The mitochondrial membrane potential $(\Delta\Psi_m)$ was also prominently decreased in the HS-1200 treated cells. Conclusion : These findings suggest that the HS-1200 - induced apoptosis of human colon cancer cells (HT-29) is mediated via caspase and mitochondrial pathways.