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Lack of Metabolic Activation and Predominant Formation of an Excreted Metabolite of Nontoxic Platynecine-Type Pyrrolizidine Alkaloids

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CHEMICAL RESEARCH IN TOXICOLOGY 2014年第1期27卷 7-16页

作者： Ruan, Jianqing Liao, Cangsong Ye, Yang Lin, Ge Chinese Univ Hong Kong Fac Med Sch Biomed Sci Hong Kong Hong Kong Peoples R China Chinese Acad Sci Shanghai Inst Mat Med Joint Res Lab Promoting Globalizat Tradit Chinese Beijing 100864 Peoples R China Chinese Univ Hong Kong Hong Kong Hong Kong Peoples R China Chinese Acad Sci Shanghai Inst Mat Med State Key Lab Drug Res Beijing 100864 Peoples R China Chinese Acad Sci Shanghai Inst Mat Med Nat Prod Chem Dept Beijing 100864 Peoples R China

Pyrrolizidine alkaloid (PA) poisoning is well-known because of the intake of PA-containing plant-derived natural products and PA-contaminated foodstuffs. Based on different structures of the necine bases, PAs are classified into three types: retronecine, otonecine, and platynecine type. The former two type PAs possessing an unsaturated necine base with a 1,2-double bond are hepatotoxic due to the P450-mediated metabolic activation to generate reactive pyrrolic ester, which interacts with cellular macromolecules leading to toxicity. With a saturated necine base, platynecine-type PAs are reported to be nontoxic and their nontoxicity was hypothesized to be due to the absence of metabolic activation;however, the metabolic pathway responsible for their nontoxic nature is largely unknown. In the present study, to prove the absence of metabolic activation in nontoxic platynecine-type PM, hepatic metabolism of platyphylline (PLA), a representative platynecine-type PA, was investigated and directly compared with the representatives of two toxic types of PAs in parallel. By determining the pyrrolic ester-derived glutathione conjugate, our results confirmed that the major metabolic pathway of PLA did not lead to formation of the reactive pyrrolic ester. More interestingly, having a metabolic rate similar to that of toxic PAs, PLA also underwent oxidative metabolisms mediated by P450s, especially P450 3A4, the same enzyme that catalyzes metabolic activation of two toxic types of PAs. However, the predominant oxidative dehydrogenation pathway of PLA formed a novel metabolite, dehydroplatyphylline carboxylic acid, which. was water-soluble, readily excreted, and could not interact with cellular macromolecules. In conclusion, our study confirmed that the saturated necine bases determine the absence of metabolic activation and thus govern the metabolic pathway responsible for the nontoxic nature of platynecine-type PAS.

关键词： programmable logic arrays Pyrrolizidine Alkaloids Metabolic activation Metabolic Pathways protactinium

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Are Physical Activity Levels Linked to Nutrient Adequacy? Implications for Cancer Risk

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NUTRITION AND CANCER-AN INTERNATIONAL JOURNAL 2014年第2期66卷 214-224页

作者： Csizmadi, Ilona Kelemen, Linda E. Speidel, Thomas Yuan, Yan Dale, Laura C. Friedenreich, Christine M. Robson, Paula J. Alberta Hlth Serv CancerControl Alberta Dept Populat Hlth Res Calgary AB T2W 3N2 Canada Univ Calgary Fac Med Dept Oncol Calgary AB Canada Univ Calgary Dept Med Genet Calgary AB Canada Univ Alberta Sch Publ Hlth Edmonton AB Canada Alberta Hlth Serv CancerControl Alberta Edmonton AB Canada Univ Alberta Fac Agr Life & Environm Sci Dept Agr Food & Nutr Sci Edmonton AB Canada

Cancer prevention guidelines recommend a healthy body mass index, physical activity, and nutrient intake from food rather than supplements. Sedentary individuals may restrict energy intake to prevent weight gain and in so doing may compromise nutritional intake. We conducted a cross-sectional analysis to determine if adequacy of micronutrients is linked to physical activity levels (PALs) in healthy-weight adults. Tomorrow Project participants in Alberta, Canada (n = 5333), completed past-year diet and physical activity questionnaires. The percent meeting Dietary Reference Intakes (DRIs) was reported across low and high PAL groups, and the relation between PAL and percent achieved DRI was determined using multiple linear regression analyses. Overall, <50% of healthy-weight participants met DRIs for folate, calcium, and vitamin D. Percent achieved DRI increased linearly with increasing PAL in both genders (P < 0.01). A hypothetical increase in PAL from 1.4 to 1.9 was associated with a DRI that was 8%-13% higher for folate and vitamin C (men) and 5%-15% higher for calcium and iron (women). Healthy-weight adults at higher PALs appear more likely to meet DRIs for potential cancer-preventing nutrients. The benefits of higher PALs may extend beyond the usual benefits attributed to physical activity to include having a more favorable impact on nutrient adequacy.

关键词： SHCBP1 gene Physical Activity Level cancer risk Direct reduced iron ACTIVITY LEVELS Motor Activity Cross-Sectional Studies Percent Folate programmable logic arrays Energy Intake LRIT1 gene ADEQUACY

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Structural Evolution of Polylactide Molecular Bottlebrushes: Kinetics Study by Size Exclusion Chromatography, Small Angle Neutron Scattering, and Simulations

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ACS MACRO LETTERS 2014年第9期3卷 862-866页

作者： Ahn, Suk-kyun Carrillo, Jan-Michael Y. Han, Youngkyu Kim, Tae-Hwan Uhrig, David Pickel, Deanna L. Hong, Kunlun Kilbey, S. Michael, II Sumpter, Bobby G. Smith, Gregory S. Do, Changwoo Oak Ridge Natl Lab Ctr Nanophase Mat Sci Oak Ridge TN 37831 USA Oak Ridge Natl Lab Natl Ctr Computat Sci Oak Ridge TN 37831 USA Oak Ridge Natl Lab Neutron Sci Directorate Biol & Soft Matter Div Oak Ridge TN 37831 USA Oak Ridge Natl Lab Comp Sci & Math Div Oak Ridge TN 37831 USA Univ Tennessee Dept Chem Knoxville TN 37996 USA Univ Tennessee Dept Chem & Biomol Engn Knoxville TN 37996 USA Korea Atom Energy Res Inst Dept Reactor Utilizat & Dev Neutron Sci Div Taejon South Korea

Structural evolution from poly(lactide) (PLA) macromonomer to resultant PLA molecular bottlebrush during ring opening metathesis polymerization (ROMP) was investigated for the first time by combining size exclusion chromatography (SEC), small-angle neutron scattering (SANS), and coarse-grained molecular dynamics (CG-MD) simulations. Multiple aliquots were collected at various reaction times during ROMP and subsequently analyzed by SEC and SANS. These complementary techniques enable the understanding of systematic changes in conversion, molecular weight and dispersity as well as structural details of PLA molecular bottlebrushes. CG-MD simulation not only predicts the experimental observations, but it also provides further insight into the analysis and interpretation of data obtained in SEC and SANS experiments. We find that PLA molecular bottlebrushes undergo three conformational transitions with increasing conversion (i.e., increasing the backbone length): (1) from an elongated to a globular shape due to longer side chain at low conversion, (2) from a globular to an elongated shape at intermediate conversion caused by excluded volume of PLA side chain, and (3) the saturation of contour length at high conversion due to chain transfer reactions.

关键词： programmable logic arrays globular shape Reaction Time ring opening metathesis polymerization Excluded volume Polylactides Secant simulating Size-exclusion chromatography

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Theoretical and experimental study of a circular imprint process for fabricating polylactide stents

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JAPANESE JOURNAL OF APPLIED PHYSICS 2014年第6期53卷 06JK04-06JK04页

作者： Teng, Ping-Tun Chang, Fuh-Yu Lin, Meng-Jye Chang, Yu-Ting Liang, Po-Chin Huang, Kai-Wen Natl Taiwan Univ Sci & Technol Dept Mech Engn Taipei 10607 Taiwan Natl Taiwan Univ Natl Taiwan Univ Hosp Dept Internal Med Coll Med Taipei 100 Taiwan Natl Taiwan Univ Natl Taiwan Univ Hosp Dept Med Imaging Coll Med Taipei 100 Taiwan Natl Taiwan Univ Natl Taiwan Univ Hosp Dept Surg Coll Med Taipei 100 Taiwan

This study presents the concept for a circular imprint process for polylactide (PLA) stent fabrication that can reduce processing time and costs compared to traditional processes. The properties of PLA were measured for the theoretical simulation of the PLA stent firstly. Two proposed simulation models were built to predict the filling rate of the PLA material in the circular imprint process by the finite volume method (FVM) and to comprehend the compressibility of the PLA stent using the finite element method (FEM). A specially designed circular mold and imprint system are employed to imprint the stent structure. Experimental results show a similar trend to the theoretical results for the circular imprint process under varying conditions. Moreover, a filling rate of up to 98.3% can be achieved, and the PLA stent, which had good material properties and compressibility, was fabricated successfully using the circular imprint system. (C) 2014 The Japan Society of Applied Physics

关键词： programmable logic arrays Compressibility filling rate Finite element method Polylactides Material properties circular Stents

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Evolving Hierarchical Low Disruption Fault Tolerance Strategies for a Novel programmable Device

Evolving Hierarchical Low Disruption Fault Tolerance Strateg...

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IEEE International Conference on Evolvable Systems (ICES)

作者： Lawson, David M. R. Walker, James Alfred Trefzer, Martin A. Bale, Simon J. Tyrrell, Andy M. Univ York Dept Elect Intelligent Syst Grp York YO10 5DD N Yorkshire England

ISBN: (纸本)9781479944798

Faults can occur in transistor circuits at any time, and increasingly so as fabrication processes continue to shrink. This paper describes the use of evolution in creating fault recovery strategies for use on the PAnDA architecture. Previous work has shown how such strategies, applied in a random but biased fashion can be used to overcome transistor faults and also how, without knowledge of the fault, the average time to find a fix could be reduced. This work presents a further optimisation where an Evolutionary Algorithm (EA) is used to optimise the order that deterministic strategies are applied to a faulty circuit in order to reduce the average time to find a fix. The two methods are compared and this comparison is used to set the path for future work.

关键词： evolutionary computation fault tolerance programmable logic arrays reconfigurable architectures transistor circuits EA PAnDA architecture evolutionary algorithm fault recovery strategies hierarchical low disruption fault tolerance strategies programmable analogue and digital array architecture programmable device transistor faults Analytical models Circuit faults Computed tomography Computer architecture logic gates MOS devices Transistors transistor circuits evolutionary algorithm programmable device programmable logic arrays Circuit faults Fault tolerance Reconfigurable architectures Computer Architecture METAL OXIDE SEMICONDUCTORS Transistor Device Component logic gates ANALYSIS MODELS Policies and plans X-Ray Computed Tomography

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Comparison of Attractor Reconstruction and HRV Methods for Analysing Blood Pressure Data 41

Comparison of Attractor Reconstruction and HRV Methods for A...

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41st Computing in Cardiology Conference (CinC)

作者： Aston, Philip J. Nandi, Manasi Christie, Mark I. Huang, Ying H. Univ Surrey Guildford GU2 7XH Surrey England Kings Coll London London WC2R 2LS England

ISBN: (纸本)9781479943463

Many methods have been proposed for analysing high frequency blood pressure or ECG data. We review a recently proposed new approach for analysing such data based on attractor reconstruction and compare it to heart rate variability that analyses the beat-to-beat intervals. Our new approach uses all the available data and so can detect changes in the shape of the waveform.

关键词： bioelectric potentials blood pressure measurement data analysis electrocardiography medical signal processing signal reconstruction ECG data analysis HRV methods attractor reconstruction methods beat-to-beat interval analysis heart rate variability high frequency blood pressure analysis Abstracts Animals Delays programmable logic arrays

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Optimizing Solder Joints on Biodegradable PCBs with Vapour Phase Soldering 37

Optimizing Solder Joints on Biodegradable PCBs with Vapour P...

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37th International Spring Seminar on Electronics Technology (ISSE) - Advances in Electronic System Integration

作者： Geczy, Attila Gal, Laszlo Hajdu, Istvan Kovacs, Balint Nagy, Daniel Ruszinko, Miklos Budapest Univ Technol & Econ Dept Elect Technol Budapest Hungary

ISBN: (纸本)9781479944552

The paper focuses on biodegradable Printed Circuit Boards (PCB) from the aspect of PCB fabrication technology and soldering. Different biodegradable Cellulose Acetate (CA) PCBs were used during the tests (one sided and two sided), and the possible application of pre-preg was also taken into account to improve pad adhesion on the base material. The surfaces of the boards were evaluated in order to obtain information about copper adhesion. FR4 test boards were also investigated as a reference, both for soldering and surface analyses. The soldering profile setup was focused on minimizing high temperatures on the heat-sensitive biopolymer substrates. The soldering profiles were created with a custom vapour phase soldering (VPS) device. The customized solder profile setting is conducted with an adaptive temperature-tracker sample holder. The boards and the solder joints were investigated with non-destructive optical microscopy, X-ray microscopy (deformation and joint analysis), and destructive shear tests. The results are promising for future application of biodegradable PCBs.

关键词： Copper programmable logic arrays Rough surfaces Soldering Substrates Surface roughness Soldering Solder Joint Device Component Rough surfaces Substrates Surface roughness Copper VAPOUR DEPOSITION WELDING programmable logic arrays Polychlorinated Biphenyls BOARDS Prepregs BIODEGRADABLE biodegradability Printed Circuit Board Device Component

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Experimental Validation of Wireless Load Sharing Method for Isolated AC Microgrids

Experimental Validation of Wireless Load Sharing Method for ...

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Electrical Power and Energy Conference (EPEC)

作者： Guzman, Cristina Agbossou, Kodjo Cardenas, Alben UQTR IRH Trois Rivieres PQ Canada

ISBN: (纸本)9781479960385

the efficient integration of Distributed Generation (DG) systems, taking as main energy source the renewable energies is nowadays a great challenge. To integrate them into a whole power sharing system as a part of an autonomous microgrid, the Droops control is a local alternative to control the power interfaces such as voltage source inverters (VSI) in order to share the common load power and to supply frequency/voltage required by the load. The objective of this paper is the demonstration of a power sharing strategy achieved with a wireless master/slave load configuration. The strategy involves a Direct Droops (D-Droops) control scheme for the master mode operation and an Inverse Droops (I-Droops) control scheme for the slave mode operation, this last following the frequency and the voltage imposed by the master VSI. The synchronization of VSIs, the signals estimation and the frequency tracking have been efficiently achieved using ADALINE network (ADAptive LInear NEuron). Experimental results using a real microgrid test bench with Field programmable Gate Array embedded devices (FPGA) for the hardware implementation of each VSIs control demonstrate the validity of the strategy proposed.

关键词： Distributed power generation Droops control FPGA hardware programming power measurement programmable logic arrays artificial neural networks

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Full Custom Implementation of a S-Box Circuit Architecture Using Power Gated PLA Structure 57

Full Custom Implementation of a S-Box Circuit Architecture U...

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57th IEEE International Midwest Symposium on Circuits and Systems (MWSCAS)

作者： Lee, Ho Joon Kim, Yong-Bin Kim, Kyung Ki Northeastern Univ Dept Elect & Comp Engn Boston MA 02115 USA Daegu Univ Dept Elect Engn Gyongsan 712714 South Korea

ISBN: (纸本)9781479941322

Advanced Encryption Standard (AES) is one of the most common symmetric encryption algorithms. The hardware complexity in AES is dominated by AES substitution box (S-Box), which is considered as one of the most complicated and costly part of the system because it is the only non-linear structure. This paper presents a low power design of Rijndael S-Box for the Sub Byte transformation using power-gating and PLA design techniques to reduce area and leakage power during standby mode. The proposed design has been implemented using 0.11um CMOS process with 1.2V power supply. The proposed design reduces the total leakage power and the total transistor count to 10% and 50% of the conventional design, respectively while improving the speed performance by ten times.

关键词： Computer architecture Delays Encryption Hardware logic gates programmable logic arrays Transistors Computer Architecture programmable logic arrays Transistor Device Component logic gates S-box cryptography Computer hardware leakage power speed performance AES gene Auger electron spectroscopy delay Advanced Encryption Standard

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A Contour Preserving FPGA Architecture for PAL to XGA Format Conversion 12

A Contour Preserving FPGA Architecture for PAL to XGA Format...

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12th IEEE International New Circuits and Systems Conference (IEEE NEWCAS)

作者： Amiel, Frederic Barry, Boubacar Trocan, Maria Inst Superieur Elect Paris F-75006 Paris France

ISBN: (纸本)9781479948857

Frame format conversion represents a key part of video display systems, as usually the transmission video stream resolution is different from the screen resolution of the digital display. In this paper a contour-preserving approach for video up-scaling is proposed, along with a low-cost, efficient FPGA architecture for one of the most used format conversions, namely PAL to XGA. The algorithm first checks for edges existence within the region around the pixel to be interpolated and adapts the scaling method following the contour direction. This adaptive system keeps the edges sharp and provides good quality scaled video sequences when compared with other scaling methods. Moreover, we propose an FPGA implementation for handling the algorithm reload, very efficient in terms of resources and complexity.

关键词： Complexity theory Computer architecture Field programmable gate arrays Image edge detection Interpolation Power demand Streaming media Field programmable gate arrays Edge detection Streaming Video Power demand Computer Architecture Complexity theory Interpolation format conversion Digital displays programmable logic arrays LRIT1 gene SHCBP1 gene scaling method

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