2,5-Hexanedione induces apoptosis via a mitochondriamediated pathway in PC12 cells

Yuan Qi,Shuang-yue Li,Feng-yuan Piao,Zhe-min Wang,Ruo-lin Chen,Shuang Liu,Jing-shun Shen 대한독성 유전단백체 학회 2015 Molecular & cellular toxicology Vol.11 No.1

2,5-Hexanedione (HD) is the main active metabolite of n-hexane and mediates the neurotoxicity of the parent compound. Studies suggested that apoptosis involved in HD neurotoxicity. However, the mechanism of HD-induced neuronal apoptosis remains unknown. To explore its underlying mechanism, we treated PC12 cells with 5, 10 and 20 mM HD for 24 h, respectively. We found that HD induced apoptotic death in PC12 cells in a dose-dependent manner. Moreover, HD down-regulated Bcl-2 expression, up-regulated Bax expression and Bax/Bcl-2 ratio, promoted the disruption of mitochondrial transmembrane potential, induced the release of cytochrome c from mitochondria, and increased the activity of caspase-3 in PC12 cells, which were all the key regulators of intrinsic apoptotic pathway. These results indicate that HD induces apoptosis via a mitochondria- mediated pathway in PC12 cells.

Different Regulation of Atrial ANP Release through Neuropeptide Y₂ and Y₄ Receptors

Feng Lian Piao,Kuichang Yuan,Guang Yi Bai,한정희,박우현,김선희 대한의학회 2008 Journal of Korean medical science Vol.23 No.6

Neuropeptide Y (NPY) receptors are present in cardiac membranes. However, its physiological roles in the heart are not clear. The aim of this study was to define the direct effects of pancreatic polypeptide (PP) on atrial dynamics and atrial natriuretic peptide (ANP) release in perfused beating atria. Pancreatic polypeptides, a NPY Y₄ receptor agonist, decreased atrial contractility but was not dose-dependent. The ANP release was stimulated by PP in a dose-dependent manner. GR 23118, a NPY Y₄ receptor agonist, also increased the ANP release and the potency was greater than PP. In contrast, peptide YY (3-36) (PYY), an NPY Y2 receptor agonist, suppressed the release of ANP with positive inotropy. NPY, an agonist for Y1, 2, 5 receptor, did not cause any significant changes. The pretreatment of NPY (18-36), an antagonist for NPY Y₃ receptor, markedly attenuated the stimulation of ANP release by PP but did not affect the suppression of ANP release by PYY. BIIE0246, an antagonist for NPY Y₂ receptor, attenuated the suppression of ANP release by PYY. The responsiveness of atrial contractility to PP or PYY was not affected by either of the antagonists. These results suggest that NPY Y₄ and Y₂ receptor differently regulate the release of atrial ANP.

Different Regulation of Atrial ANP Release through Neuropeptide Y ₂ and Y ₄ Receptors

Piao, Feng Lian,Yuan, Kuichang,Bai, Guang Yi,Han, Jeong Hee,Park, Woo Hyun,Kim, Suhn Hee The Korean Academy of Medical Sciences 2008 JOURNAL OF KOREAN MEDICAL SCIENCE Vol.23 No.6

<P>Neuropeptide Y (NPY) receptors are present in cardiac membranes. However, its physiological roles in the heart are not clear. The aim of this study was to define the direct effects of pancreatic polypeptide (PP) on atrial dynamics and atrial natriuretic peptide (ANP) release in perfused beating atria. Pancreatic polypeptides, a NPY Y<SUB>4</SUB> receptor agonist, decreased atrial contractility but was not dose-dependent. The ANP release was stimulated by PP in a dose-dependent manner. GR 23118, a NPY Y<SUB>4</SUB> receptor agonist, also increased the ANP release and the potency was greater than PP. In contrast, peptide YY (3-36) (PYY), an NPY Y<SUB>2</SUB> receptor agonist, suppressed the release of ANP with positive inotropy. NPY, an agonist for Y<SUB>1, 2, 5</SUB> receptor, did not cause any significant changes. The pretreatment of NPY (18-36), an antagonist for NPY Y<SUB>3</SUB> receptor, markedly attenuated the stimulation of ANP release by PP but did not affect the suppression of ANP release by PYY. BIIE0246, an antagonist for NPY Y<SUB>2</SUB> receptor, attenuated the suppression of ANP release by PYY. The responsiveness of atrial contractility to PP or PYY was not affected by either of the antagonists. These results suggest that NPY Y<SUB>4</SUB> and Y<SUB>2</SUB> receptor differently regulate the release of atrial ANP.</P>

High Performance Current Sensing Circuit for Current-Mode DC-DC Buck Converter

Hai-Feng Jin,Hua-Lan Piao,Zhi-Yuan Cui,김남수 한국전기전자재료학회 2010 Transactions on Electrical and Electronic Material Vol.11 No.1

A simulation study of a current-mode direct current (DC)-DC buck converter is presented in this paper. The converter, with a fully integrated power module, is implemented by using sense method metal-oxide-semiconductor field-effect transistor (MOSFET) and bipolar complementary metal–oxide–semiconductor (BiCMOS) technology. When the MOSFET is used in a current sensor, the sensed inductor current with an internal ramp signal can be used for feedback control. In addition, the BiCMOS technology is applied in the converter for an accurate current sensing and a low power consumption. The DC-DC converter is designed using the standard 0.35 μm CMOS process. An off-chip LC filter is designed with an inductance of 1 mH and a capacitance of 12.5 nF. The simulation results show that the error between the sensing signal and the inductor current can be controlled to be within 3%. The characteristics of the error amplification and output ripple are much improved, as compared to converters using conventional CMOS circuits.

High Performance Current Sensing Circuit for Current-Mode DC-DC Buck Converter

Jin, Hai-Feng,Piao, Hua-Lan,Cui, Zhi-Yuan,Kim, Nam-Soo The Korean Institute of Electrical and Electronic 2010 Transactions on Electrical and Electronic Material Vol.11 No.1

A simulation study of a current-mode direct current (DC)-DC buck converter is presented in this paper. The converter, with a fully integrated power module, is implemented by using sense method metal-oxide-semiconductor field-effect transistor (MOSFET) and bipolar complementary metal-oxide-semiconductor (BiCMOS) technology. When the MOSFET is used in a current sensor, the sensed inductor current with an internal ramp signal can be used for feedback control. In addition, the BiCMOS technology is applied in the converter for an accurate current sensing and a low power consumption. The DC-DC converter is designed using the standard $0.35\;{\mu}m$ CMOS process. An off-chip LC filter is designed with an inductance of 1 mH and a capacitance of 12.5 nF. The simulation results show that the error between the sensing signal and the inductor current can be controlled to be within 3%. The characteristics of the error amplification and output ripple are much improved, as compared to converters using conventional CMOS circuits.

Degradation of Lignocelluloses in Rice Straw by BMC-9, a Composite Microbial System

( Hongyan Zhao ),( Hai Ru Yu ),( Xu Feng Yuan ),( Ren Zhe Piao ),( Hu Lin Li ),( Xiao Fen Wang ),( Zong Jun Cui ) 한국미생물 · 생명공학회 2014 Journal of microbiology and biotechnology Vol.24 No.5

To evaluate the potential utility of pretreatment of raw biomass with a complex microbial system, we investigated the degradation of rice straw by BMC-9, a lignocellulose decomposition strain obtained from a biogas slurry compost environment. The degradation characteristics and corresponding changes in the bacterial community were assessed. The results showed that rapid degradation occurred from day 0 to day 9, with a peak total biomass bacterium concentration of 3.3 × 10(8) copies/ml on day 1. The pH of the fermentation broth declined initially and then increased, and the mass of rice straw decreased steadily. The highest concentrations of volatile fatty acid contents (0.291 mg/l lactic acid, 0.31 mg/l formic acid, 1.93 mg/l acetic acid, and 0.73 mg/l propionic acid) as well as the highest xylanse activity (1.79 U/ml) and carboxymethyl cellulase activity (0.37 U/ml) occurred on day 9. The greatest diversity among the microbial community also occurred on day 9, with the presence of bacteria belonging to Clostridium sp., Bacillus sp., and Geobacillus sp. Together, our results indicate that BMC-9 has a strong ability to rapidly degrade the lignocelluloses of rice straw under relatively inexpensive conditions, and the optimum fermentation time is 9 days.

Effects of dietary valine:lysine ratio on the performance, amino acid composition of tissues and mRNA expression of genes involved in branched-chain amino acid metabolism of weaned piglets

Ye Tong Xu,Xiao Kang Ma,Chun Lin Wang,Ming Feng Yuan,Xiang Shu Piao 아세아·태평양축산학회 2018 Animal Bioscience Vol.31 No.1

Objective: The goal of this study was to investigate the effects of dietary standard ileal digestible (SID) valine:lysine ratios on performance, intestinal morphology, amino acids of liver and muscle, plasma indices and mRNA expression of branched-chain amino acid (BCAA) metabolism enzymes. Methods: A total of 144 crossbred pigs (Duroc×Landrace×Large White) weaned at 28±4 days of age (8.79±0.02 kg body weight) were randomly allotted to 1 of 4 diets formulated to provide SID valine:lysine ratios of 50%, 60%, 70%, or 80%. Each diet was fed to 6 pens of pigs with 6 pigs per pen (3 gilts and 3 barrows) for 28 days. Results: Average daily gain increased quadratically (p<0.05), the villous height of the duodenum, jejunum and ileum increased linearly (p<0.05) as the SID valine:lysine ratio increased. The concentrations of plasma α-keto isovaleric and valine increased linearly (p<0.05), plasma aspartate, asparagine and cysteine decreased (p<0.05) as the SID valine:lysine ratio increased. An increase in SID lysine:valine levels increased mRNA expression levels of mitochondrial BCAA transaminase and branched-chain α-keto acid dehydrogenase in the longissimus dorsi muscle (p<0.05). Conclusion: Using a quadratic model, a SID valine:lysine ratio of 68% was shown to maximize the growth of weaned pigs which is slightly higher than the level recommended by the National Research Council [6].