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111.
112.
Chemical synapses are highly specialized cell–cell junctions designed for efficient signaling between nerve cells. Distinct
cytoskeletal matrices are assembled at either side of the synaptic junction. The presynaptic cytomatrix at the active zone
(CAZ) defines and organizes the site of neurotransmitter release from presynaptic nerve terminals. The postsynaptic density
(PSD) tethers neurotransmitter receptors and the postsynaptic signal transduction machinery. Recent progress in the identification
and characterization of novel CAZ and PSD components has revealed new insights into the molecular organization and assembly
mechanisms of the synaptic neurotransmission apparatus. On the presynaptic side, Bassoon and Piccolo, two related giant proteins,
are crucially involved in scaffolding the CAZ. On the postsynaptic side, two families of multi-domain adaptor proteins, the
MAGuKs (membrane-associated guanylate kinase homologs) and the ProSAP (proline-rich synapse-associated protein, also termed
Shank) family members are thought to be major organizing molecules of the PSD. 相似文献
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John S. Rinehart 《Die Naturwissenschaften》1976,63(5):218-223
117.
This paper describes a method for determining reductions of SO2 emissions from coal- and oil-fired power stations, oil refineries and large industrial units in the UK taking into account their pollution potential. The method is based on the use of two gridded data sets: critical loads, which represent the sensitivity of the environment to acid deposition and modelled estimates of total (wet + dry) sulphur deposition for 646 point sources within the UK. An iterative method is used to identify and subsequently reduce emissions from point sources that contribute most to areas of critical loads exceedance. This paper demonstrates how the method may be used to determine an optimal allocation of emissions across the UK which yields the maximum amount of environmental protection per unit of emission.The paper then goes on to consider the changes that will have to take place within the UK power generation industry in order to meet the revised EC Large Combustion Plant Directive which comes into force on 1 January 2008. Particular emphasis is placed upon proposed emissions trading schemes and the environmental implications of allowing trading between stations with high and low pollution potentials. The paper concludes by suggesting that the emissions trading process should take into account the pollution potential of each source, irrespective of whether the proposed emission is within the plant's agreed emission limit. An approach based entirely on minimizing environmental damage rather than one which takes cost into account, as in current integrated assessment modelling, could provide an interesting approach across the rest of Europe. 相似文献
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Denise A. S. Batista PhD Cathleen Escallon Karin J. Blakemore Gail Stetten 《黑龙江环境通报》1995,15(2):123-127
We report a 16-month-old boy with delayed psychomotor development, dysmorphic features, and failure to thrive. He had a mosaic karyotype detected prenatally: mos 46,XY/47,XY,+r(20)/47,XY,+20. After birth, the abnormal cell lines were confirmed in a number of tissues. The small ring chromosome was identified using fluorescence in situ hybridization as derived from chromosome 20. We compared our patient with previously reported cases of mosaic trisomy 20 detected prenatally and associated with an abnormal phenotype. In an attempt to characterize an r(20) syndrome, we also compared our case with two similar reports in the literature. 相似文献