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Search Results: 1 - 10 of 109929 matches for " CHEN Pei-Feng "
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Effects of ethanol extracts of Panax notoginseng on liver metastasis of B16 melanoma grafted in mice
Pei-Feng CHEN
Zhong Xi Yi Jie He Xue Bao , 2006,
Abstract: Objective: To observe the effects of ethanol extracts of Panax notoginseng on the tumor and the liver metastasis in experimental mice grafted with B16 melanoma. Methods: B16 melanoma was transplanted in the spleen of C57BL/6 mice. The effects of different doses of ethanol extracts of Panax notoginseng on the inhibition rate of spleen tumors and the liver metastasis were observed respectively. Results: The high-, medium-, and low-doses of the extracts and the interferon-α (IFN-α) can improve the quality of life of the experimental mice. The weights of spleen tumor were lower in the low- and medium-dose extracts-treated groups and the IFN-α-treated group than that in the normal saline (NS)-treated group (P<0.05 or P<0.01). The liver metastasis was less in the low- and medium-dose extracts-treated groups and the IFN-α-treated group than that in the NS-treated group (P<0.01). Conclusion: The ethanol extracts of Panax notoginseng can improve the quality of life of the experimental mice and inhibit the growth of tumor and the liver metastasis.
DCT-based Reversible Data Hiding Scheme
Chia-Chen Lin,Pei-Feng Shiu
Journal of Software , 2010, DOI: 10.4304/jsw.5.2.214-224
Abstract: To enhance the hiding capacity of Chang et al.’s reversible DCT-based data hiding scheme, in this paper we propose another method called a layer-1 data embedding strategy. Our proposed layer-1 strategy considers some areas not used by Chang et al.’s scheme, which we call layer-2 data embedding. To achieve our objective, we applied Tian’s pixel expansion method to design our layer-1 data embedding strategy. Experimental results confirm that the hiding capacity provided by combining our strategy with Chang et al.’s is higher than that provided by the Chang et al. approach alone. Moreover, the image quality of stego-images with our proposed scheme remains above 30 dB for most test images, which is better than the best image quality offered by Chang et al.’s scheme. Finally, the security and reversibility of Chang et al.’s scheme is unaffected when their layer-2 scheme is combined with our proposed layer-1 scheme.
Road surface mirage: A bunch of hot air?
HuaiChun Zhou,ZhiFeng Huang,Qiang Cheng,Wei Lü,Kui Qiu,Chen Chen,Pei-feng Hsu
Chinese Science Bulletin , 2011, DOI: 10.1007/s11434-011-4347-9
Abstract: The inferior mirage from road surfaces is a common phenomenon, which can be easily seen in everyday life. It has been recognized in the literature as a light refraction phenomenon due to the refractive index gradient caused by the temperature gradient in the air strata above the road surfaces. However, it was also suggested that the mirage is just a phenomenon of specular reflection at grazing incidence. Because of the lack of reasonable and quantitative evidence, the generally accepted light refraction theory has not yet been refuted. Here we show some mirror-like reflection images captured from a road surface stretch in Yujiashan North Road, Wuhan, China, when there was no obvious temperature gradient on or above the road, measured on a winter day in December 2009. This provided direct evidence to doubt the temperature induced light refraction mechanism of the inferior mirage. Furthermore, the critical grazing angle of about 0.2° to the road plane where the mirror-like reflection appears could not make the rough surface scatter incident light as a smooth surface according to the Rayleigh criterion. Therefore the phenomenon is a mirrorlike observation effect of scattering from the surface, which cannot be entirely explained by light refraction via air strata. The results demonstrate that the image-formation mechanism and the observer-based-analysis method shown here potentially offer a means of understanding a wide range of scattering phenomena from rough surfaces at grazing angle; for example, the superior mirages of unusual brightness occasionally observed over frozen lakes and the off-specular reflection phenomenon.
Correlations between the Signal Complexity of Cerebral and Cardiac Electrical Activity: A Multiscale Entropy Analysis
Pei-Feng Lin, Men-Tzung Lo, Jenho Tsao, Yi-Chung Chang, Chen Lin, Yi-Lwun Ho
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0087798
Abstract: The heart begins to beat before the brain is formed. Whether conventional hierarchical central commands sent by the brain to the heart alone explain all the interplay between these two organs should be reconsidered. Here, we demonstrate correlations between the signal complexity of brain and cardiac activity. Eighty-seven geriatric outpatients with healthy hearts and varied cognitive abilities each provided a 24-hour electrocardiography (ECG) and a 19-channel eye-closed routine electroencephalography (EEG). Multiscale entropy (MSE) analysis was applied to three epochs (resting-awake state, photic stimulation of fast frequencies (fast-PS), and photic stimulation of slow frequencies (slow-PS)) of EEG in the 1–58 Hz frequency range, and three RR interval (RRI) time series (awake-state, sleep and that concomitant with the EEG) for each subject. The low-to-high frequency power (LF/HF) ratio of RRI was calculated to represent sympatho-vagal balance. With statistics after Bonferroni corrections, we found that: (a) the summed MSE value on coarse scales of the awake RRI (scales 11–20, RRI-MSE-coarse) were inversely correlated with the summed MSE value on coarse scales of the resting-awake EEG (scales 6–20, EEG-MSE-coarse) at Fp2, C4, T6 and T4; (b) the awake RRI-MSE-coarse was inversely correlated with the fast-PS EEG-MSE-coarse at O1, O2 and C4; (c) the sleep RRI-MSE-coarse was inversely correlated with the slow-PS EEG-MSE-coarse at Fp2; (d) the RRI-MSE-coarse and LF/HF ratio of the awake RRI were correlated positively to each other; (e) the EEG-MSE-coarse at F8 was proportional to the cognitive test score; (f) the results conform to the cholinergic hypothesis which states that cognitive impairment causes reduction in vagal cardiac modulation; (g) fast-PS significantly lowered the EEG-MSE-coarse globally. Whether these heart-brain correlations could be fully explained by the central autonomic network is unknown and needs further exploration.
Lobe-Specific Calcium Binding in Calmodulin Regulates Endothelial Nitric Oxide Synthase Activation
Pei-Rung Wu, Cheng-Chin Kuo, Shaw-Fang Yet, Jun-Yang Liou, Kenneth K. Wu, Pei-Feng Chen
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0039851
Abstract: Background Human endothelial nitric oxide synthase (eNOS) requires calcium-bound calmodulin (CaM) for electron transfer but the detailed mechanism remains unclear. Methodology/Principal Findings Using a series of CaM mutants with E to Q substitution at the four calcium-binding sites, we found that single mutation at any calcium-binding site (B1Q, B2Q, B3Q and B4Q) resulted in ~2–3 fold increase in the CaM concentration necessary for half-maximal activation (EC50) of citrulline formation, indicating that each calcium-binding site of CaM contributed to the association between CaM and eNOS. Citrulline formation and cytochrome c reduction assays revealed that in comparison with nNOS or iNOS, eNOS was less stringent in the requirement of calcium binding to each of four calcium-binding sites. However, lobe-specific disruption with double mutations in calcium-binding sites either at N- (B12Q) or at C-terminal (B34Q) lobes greatly diminished both eNOS oxygenase and reductase activities. Gel mobility shift assay and flavin fluorescence measurement indicated that N- and C-lobes of CaM played distinct roles in regulating eNOS catalysis; the C-terminal EF-hands in its calcium-bound form was responsible for the binding of canonical CaM-binding domain, while N-terminal EF-hands in its calcium-bound form controlled the movement of FMN domain. Limited proteolysis studies further demonstrated that B12Q and B34Q induced different conformational change in eNOS. Conclusions Our results clearly demonstrate that CaM controls eNOS electron transfer primarily through its lobe-specific calcium binding.

WANG Pei-Feng,CHEN Gao-Feng,HUA Tie-Jun,WANG Ru-Li,

红外与毫米波学报 , 2000,
Abstract: A new method to optimize the BPOFs was proposed which can reduce the low frequency noise in output plane and improve the SNR of self correlation. By applying it to the programmable matched filtering optical correlator based on electronically addressing ferroelectric liquid crystal spatial light madulator, the opto electronic pattern recognition was realized.
Quiescent Fibroblasts Are More Active in Mounting Robust Inflammatory Responses Than Proliferative Fibroblasts
Bo-Rui Chen, Huei-Hsuan Cheng, Wei-Chung Lin, Kai-Hsuan Wang, Jun-Yang Liou, Pei-Feng Chen, Kenneth K. Wu
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0049232
Abstract: Quiescent cells are considered to be dormant. However, recent studies suggest that quiescent fibroblasts possess active metabolic profile and certain functional characteristics. We previously observed that serum-starved quiescent fibroblasts respond to proinflammatory stimuli by robust expression of cyclooxygenase-2 (COX-2), which declines after the quiescent fibroblasts are driven to proliferation. In this study, we elucidated the underlying signaling and transcriptional mechanism and identified by microarray genes with similar differential expression. By using pharmacological inhibitors coupled with gene silencing, we uncovered the key role of protein kinase C δ (PKCδ) and extracellular signal regulated protein kinase 1/2 (ERK1/2) signaling in mediating COX-2 expression in quiescent cells. Surprisingly, COX-2 expression in proliferative cells was not blocked by PKCδ or ERK1/2 inhibitors due to intrinsic inhibition of PKCδ and ERK1/2 in proliferative cells. Restrained COX-2 transcription in proliferative cells was attributable to reduced NF-κB binding. Microarray analysis identified 35 genes whose expressions were more robust in quiescent than in proliferative cells. A majority of those genes belong to proinflammatory cytokines, chemokines, adhesive molecules and metalloproteinases, which require NF-κB for transcription. Quiescent fibroblasts had a higher migratory activity than proliferative fibroblasts as determined by the transwell assay. Selective COX-2 inhibition reduced migration which was restored by prostaglandin E2. As COX-2 and inflammatory mediators induce DNA oxidation, we measured 8-hydroxydeoxyguanosine (8-OHdG) in quiescent vs. proliferative fibroblasts. PMA-induced 8-OHdG accumulation was significantly higher in quiescent than in proliferative fibroblasts. These findings indicate that quiescent fibroblasts (and probably other quiescent cells) are at the forefront in mounting inflammatory responses through expression of an array of proinflammatory genes via the PKCδ/ERK1/2 signaling pathway.
Effect of light intensity on grain quality of rice at different spike positions during grain-filling stage

DONG Ming-Hui,HUI Feng,GU Jun-Rong,CHEN Pei-Feng,YANG Dai-Feng,QIAO Zhong-Ying,
,惠 锋,顾俊荣,陈培峰,杨代凤,乔中英

中国生态农业学报 , 2013,
Abstract: Light intensity is an important ecological factor that greatly influences rice grain formation and quality. This study discussed the effects of light intensity on rice quality at grain-filling stage and the differences in variety types and spikelets at different panicle positions. To do this, two pot-grown super rice cultivars, "Yangliangyou 6" (indica) and "Wuyunjing 23" (japonica), were subjected to three light intensity treatments (71%, 55% and 40% of normal light intensity respectively) at post-anthesis grain-filling stage, with normal outdoor growth as the control. The study aimed to throw more light on the physiological mechanisms of rice grain formation to lay the theoretical basis for improved rice quality. The results suggested that light intensity during grain-filling greatly influenced rice quality. Compared with the control, rice grain quality under the three treatments worsened with the weakening of light intensity. Grain quality response to light intensity varied with light intensity degrees, variety genotypes and grain positions on rice panicles. While grain quality on spikelets with late flower formation was poorly stability, that on spikelets with early flower formation was relatively stable. Milled rice and rice amylose content decreased and chalkiness increased with the weakening of light intensity. Amplitude change in grains on primary tillers was relatively larger than in grain on secondary tillers. Also the weaker the light intensity, the lower was the breakdown value, the higher were the setback value and crud protein content, and the worse were the rice cooking and eating qualities. Reasonable sowing times based on variety type and scientific cultivation practices for improved light conditions and rice growth likely mitigated any negative impacts of low light intensity on rice quality.
Channel Temperature Measurement of AlGaN/GaN HEMTs by Forward Schottky Characteristics2010-

ZHANG Guang-Chen,FENG Shi-Wei,HU Pei-Feng,ZHAO Yan,GUO Chun-Sheng,XU Yang,CHEN Tang-Sheng,JIANG Yi-Jian,

中国物理快报 , 2011,
Correlation between chemosensitivity to anticancerdrugs and telomerase reverse transcriptase mRNAexpression in gastric cancer
Lin Wang, Pei-Feng Li, Ming Geng, Yong-Cheng Cao, Ying-Chun Yin
Diagnostic Pathology , 2013, DOI: 10.1186/1746-1596-8-33
Abstract: The GC cells which were collected from 68 patients with primary GC were primary cultured. The chemosensitivity of GC cells to anticancer drugs was evaluated successfully using the MTT assay for 60 cases of GC cells, and the hTERT mRNA expression was examined in 60 cases of GC tissues and corresponding normal gastric mucosa and 6 cases of chronic superficial gastritis mucosa by in situ hybridization.Taxol, Cisplatin and 5-Fluorouracil were in general more effective than Adriamycin and Mitomycin for GC cells, and the chemosensitivity to anticancer drugs was associated with tumor histological types and a worse tumor grade. Compared to normal gastric mucosa tissues, hTERT mRNA expression was significantly increased in GC (P<0.05), which was related with a worse differentiation and drug-resistance to 5-Fluorouracil or Adriamycin in GC.These data demonstrate for the first time that examinations of hTERT mRNA expression as an important factor could be used to select the chemotherapeutic drugs for GC patients. Virtual slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1793217009875483
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