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81.
While contemporary philosophers have been content to declare the logical possibilities of sacrifice exhausted, to have finally ‘sacrificed sacrifice,’ for many people around the world the notion of sacrifice – whether religious, secular, or somewhere in between – remains absolutely central to their understanding of themselves, their relations with others, and their place in the world. From religion to economics, and from politics to the environment, sacrificial tropes frequently emerge as key means of mediating and propagating various forms of power, moral discourse, and cultural identity. This paper lays out reasons for retaining sacrifice as an analytical concept within anthropology, and argues for the importance of a renewed focus on the ‘other side of sacrifice’, as a means of understanding better how sacrifice emerges beyond ritual and enters into the full gamut of social life. 相似文献
82.
Vessela D. Kancheva Luciano Saso Petya V. Boranova Abdullah Khan Manju K. Saroj Mukesh K. Pandey Shashwat Malhotra Jordan Z. Nechev Sunil K. Sharma Ashok K. Prasad Maya B. Georgieva Carleta Joseph Anthony L. DePass Ramesh C. Rastogi Virinder S. Parmar 《Biochimie》2010
The chain-breaking antioxidant activities of eight coumarins [7-hydroxy-4-methylcoumarin (1), 5,7-dihydroxy-4-methylcoumarin (2), 6,7-dihydroxy-4-methylcoumarin (3), 6,7-dihydroxycoumarin (4), 7,8-dihydroxy-4-methylcoumarin (5), ethyl 2-(7,8-dihydroxy-4-methylcoumar-3-yl)-acetate (6), 7,8-diacetoxy-4-methylcoumarin (7) and ethyl 2-(7,8-diacetoxy-4-methylcoumar-3-yl)-acetate (8)] during bulk lipid autoxidation at 37 °C and 80 °C in concentrations of 0.01–1.0 mM and their radical scavenging activities at 25 °C using TLC–DPPH test have been studied and compared. It has been found that the o-dihydroxycoumarins 3–6 demonstrated excellent activity as antioxidants and radical scavengers, much better than the m-dihydroxy analogue 2 and the monohydroxycoumarin 1. The substitution at the C-3 position did not have any effect either on the chain-breaking antioxidant activity or on the radical scavenging activity of the 7,8-dihydroxy- and 7,8-diacetoxy-4-methylcoumarins 6 and 8. The comparison with DL-α-tocopherol (TOH), caffeic acid (CA) and p-coumaric acid (p-CumA) showed that antioxidant efficiency decreases in the following sequence: 相似文献
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Maya Shirakura Hidetaka Eguchi Hideaki Nakamura Keiko Hiyama Eiji Tanaka Takashi Takata 《Biochemical and biophysical research communications》2010,393(4):800-805
Vascular endothelial growth factor (Vegf) was previously shown to be expressed specifically in the condylar cartilage of temporomandibular joint-osteoarthritis (TMJ-OA) model rats. Here we demonstrate for the first time that hypoxia-inducible factor-1α (Hif-1α) is activated in mature chondrocytes of temporomandibular joint-osteoarthritis (TMJ-OA) model rat by mechanical overload, and that activated Hif-1 in chondrocytes can induce osteoclastogenesis via repression of osteoprotegerin (Opg) expression.In rat TMJs, degeneration of the condylar cartilage became prominent in proportion to the duration of overloading. Hif-1α expression was observed specifically in mature and hypertrophic chondrocytes, and Hif-1α-positivity, level of Vegf expression, and tartrate-resistant acid phosphatase (TRAP)-positive cell numbers all increased in the same manner. When ATDC5 cells induced differentiation by insulin were cultured under hypoxia, Hif-1α induction was observed in mature stage, but not in immature stage. Inductions of Hif-1-target genes showed a similar expression pattern. In addition, expression of Opg decreased in hypoxia, and Hif-1α played a role, in part, in its regulation. 相似文献
86.
In this article, we report tuning of the sensory capability of an amino acid (tryptophan) in a biomimicking anionic micellar nano cage. It has been shown that anionic surfactant concentration dictates the sensing behavior of tryptophan toward body malodor component (butyric acid) generated by bacterial degradation of tributyrin. We have proposed a fluorescence quenching mechanism that is based on short-chain fatty acid (SCFA) proximity with tryptophan present at the micelle-water interface. Anionic surfactant-induced fluorescent sensor activity of tryptophan exhibits high sensitivity (detection limit up to 10 μM) and specific selectivity (toward SCFA, < C12) in aqueous solution. We also determined antibacterial efficacy of various zinc salts based on the sensory activity of tryptophan, which has been correlated with the established resazurin assay. 相似文献
87.
Pavel Dolezal Michael J. Dagley Maya Kono Peter Wolynec Vladimir A. Liki? Jung Hock Foo Miroslava Sedinová Jan Tachezy Anna Bachmann Iris Bruchhaus Trevor Lithgow 《PLoS pathogens》2010,6(3)
Several essential biochemical processes are situated in mitochondria. The metabolic transformation of mitochondria in distinct lineages of eukaryotes created proteomes ranging from thousands of proteins to what appear to be a much simpler scenario. In the case of Entamoeba histolytica, tiny mitochondria known as mitosomes have undergone extreme reduction. Only recently a single complete metabolic pathway of sulfate activation has been identified in these organelles. The E. histolytica mitosomes do not produce ATP needed for the sulfate activation pathway and for three molecular chaperones, Cpn60, Cpn10 and mtHsp70. The already characterized ADP/ATP carrier would thus be essential to provide cytosolic ATP for these processes, but how the equilibrium of inorganic phosphate could be maintained was unknown. Finally, how the mitosomal proteins are translocated to the mitosomes had remained unclear. We used a hidden Markov model (HMM) based search of the E. histolytica genome sequence to discover candidate (i) mitosomal phosphate carrier complementing the activity of the ADP/ATP carrier and (ii) membrane-located components of the protein import machinery that includes the outer membrane translocation channel Tom40 and membrane assembly protein Sam50. Using in vitro and in vivo systems we show that E. histolytica contains a minimalist set up of the core import components in order to accommodate a handful of mitosomal proteins. The anaerobic and parasitic lifestyle of E. histolytica has produced one of the simplest known mitochondrial compartments of all eukaryotes. Comparisons with mitochondria of another amoeba, Dictystelium discoideum, emphasize just how dramatic the reduction of the protein import apparatus was after the loss of archetypal mitochondrial functions in the mitosomes of E. histolytica. 相似文献
88.
LKB1/STRAD promotes axon initiation during neuronal polarization 总被引:3,自引:0,他引:3
Axon/dendrite differentiation is a critical step in neuronal development. In cultured hippocampal neurons, the accumulation of LKB1 and STRAD, two interacting proteins critical for establishing epithelial polarity, in an undifferentiated neurite correlates with its subsequent axon differentiation. Downregulation of either LKB1 or STRAD by siRNAs prevented axon differentiation, and overexpression of these proteins led to multiple axon formation. Furthermore, interaction of STRAD with LKB1 promoted LKB1 phosphorylation at a PKA site S431 and elevated the LKB1 level, and overexpressing LKB1 with a serine-to-alanine mutation at S431 (LKB1(S431A)) prevented axon differentiation. In developing cortical neurons in vivo, downregulation of LKB1 or overexpression of LKB1(S431A) also abolished axon formation. Finally, local exposure of the undifferentiated neurite to brain-derived neurotrophic factor or dibutyryl-cAMP promoted axon differentiation in a manner that depended on PKA-dependent LKB1 phosphorylation. Thus local LKB1/STRAD accumulation and PKA-dependent LKB1 phosphorylation represents an early signal for axon initiation. 相似文献
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Lambrev PH Tsonev T Velikova V Georgieva K Lambreva MD Yordanov I Kovács L Garab G 《Photosynthesis research》2007,94(2-3):321-332
The kinetics of non-photochemical quenching (NPQ) of chlorophyll fluorescence was studied in pea leaves at different temperatures
between 5 and 25°C and during rapid jumps of the leaf temperature. At 5°C, NPQ relaxed very slowly in the dark and was sustained
for up to 30 min. This was independent of the temperature at which quenching was induced. Upon raising the temperature to
25°C, the quenched state relaxed within 1 min, characteristic for qE, the energy-dependent component of NPQ. Measurements
of the membrane permeability (ΔA515) in dark-adapted and preilluminated leaves and NPQ in the presence of dithiothreitol strongly suggest that the effect of
low temperature on NPQ was not because of limitation by the lumenal pH or the de-epoxidation state of the xanthophylls. These
data are consistent with the notion that the transition from the quenched to the unquenched state and vice versa involves
a structural reorganization in the photosynthetic apparatus. An eight-state reaction scheme for NPQ is proposed, extending
the model of Horton and co-workers (FEBS Lett 579:4201–4206, 2005), and a hypothesis is put forward concerning the nature of conformational changes associated with qE.
Electronic supplementary material The online version of this article (doi: ) contains supplementary material, which is available to authorized users. 相似文献