5,007 research outputs found

    The action of structural analogues of nicotine on synaptic transmission

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    The Relevance of Nicotine to the Study of Synaptic TransmissionI. ACTION OF NICOTINE ON TRANSMISSION IN AUTONOMIC GANGLIA: Site of Action at Ganglia 1 Chemical Transmitter 3 Identification of Acetylcholine 4 Nicotine -like Activity of Acetylcholine 5 Study of mode of Block 6 Electrophysiological study on Cat Superior cervical ganglion 7 Depolarisation Second Phase of Block: Desensitisation? 9 Comparison of Nicotine and Acetylcholine 11 Study on Isolated Ganglion of Rabbit 12 ConclusionII ACTION OF NICOTINE ON TRANSMISSION AT THE NEUROMUSCULAR JUNCTION: Chemical Transmission at Neuromuscular Junction 14 STIMULANT ACTION OF NICCOTINE: (a) Contracture 15 (b ) Contraction 16 Presence of Two Types of Fibres 17 (1) Frog 17 (2) Chick 17 Connection between Depolarisation and Contracture 19 Pharmacological difference between Fibres 20 Quantitative Comparison of the Neuromuscular Junction and the Ganglion 20 BLOCKING ACTIVITY: Introduction 21 The effects of Decamethonium on the end-plate 21 The effect of ( +) Tubocurarine on the end -plate 22 Classification into two types of block 23 The two Phases of block produced by Decamethonium 25 Microphysiological Study of Phase II 27 Differences between the effect of eserine on the block of micro and macro preparations 28 Kinetic Theory 30 (a) Intermediate Complex 30 (b) Connection between depolarisation and desensitisation 31 (c) Facilitation 34 Anticholinestèrase Activity as a Complicating Factor 35 Mode of Block by Nicotine 36 Conclusion 38III RELATIONSHIP BETWEEN CHEMICAL STRUCTURE AND NICOTINE-LIKE ACTIVITY: Choline phenyl ethers - Hey's Hypothesis 40 Hypothesis applied to Nicotine 41 Compounds Prepared 42 Preparations used 45IV PHARMACOLOGY OF RELATED COMPOUNDS 46 EXPERIMENTAL SECTION 48 Methods: .ACTIVITY AT THE NEUROMUSCULAR JUNCTION I The Rat Phrenic Nerve -Diaphragm Preparation 49 Method 5 0 II The Chicken Biventer Cervicis Preparation 51 Method 52 ACTIVITY AT GANGLIA The Cat Superior Cervical Ganglion Preparation 54 Method - (i) Antagonist Activity 56 (ii) Agonist Activity 58 ACTIVITY ON CHOLINESTERASE Enzyme Source 59 Method - (a? Control Experiments 60 (b Test of Inhibitors 63 Comment Alternative Method 65 MEASUREMENT OF DISSOCIATION CONSTANTS 67Results: ACTIVITY AT THE NEUROMUSCULAR JUNCTION I The Rat Phrenic Nerve - Diaphragm Preparation 71 II The Chick Biventer Cervicis Preparation 72 ACTIVITY AT GANGLIA The Cat Superior Cervical Ganglion: a Blocking Activity 73 b Stimulant Activity 74 ACTIVITY ON CHOLINESTERASE 75 DISSOCIATION CONSTANTS 76DISCUSSION: I SIGNIFICANCE OF THE RESULTS: Type of Action on the Rat Diaphragm 78 Type of Action on the Cat Ganglion 79 Possibility of an indirect action: 79 Anticholinesterase Activity Active Species: Ion or Salt 82 II RELATIONSHIPS BETWEEN STRUCTURE AND ACTIVITY: (a)Effect of Position of the Side Chain 84 (b) Effect of Chain Length 85 (i) Tertiary Compounds 85 (ii) Quaternary Compounds 86 (c) Effect of Quaternisation 86 (d) Activity Differences in different Tests 87 Points to be explained 89 III SPACIAL CONSIDERATIONS: Importance of Side Chain Nitrogen 90 Effect of Quaternisation of Side Chain Nitrogen 91 Importance of Pyridine Ring 91 Conclusion 94 IV THE RELEVANCE OF THIS STUDY TO THE ACTIVITY OF RELATED COMPOUNDS 95ACKNOWLEDGEMENT 97BIBLIOGRAPHY 9

    Conspiracy, security and human care in Donnersmarck's "Leben der Anderen"

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    "Florian Henckel von Donnersmarck's acclaimed film, 'Das Leben der Anderen' (2006), affords a provocative opportunity for investigating the relation between conspiracy and security. Although state-sponsored conspiracies breed insecurity among the citizenry, they nonetheless also provide the ground for epistemological security, insofar as the threat can be decisively located. In pressing the literal definition of security as 'the removal of concern', this article interprets the film according to shifting modalities of care. Considered as a vast conspiratorial network against its own populace, the East German Ministry for State Security (the Stasi) represents a mechanized, dispassionate ideal that strives to eliminate concerns about whatever may jeopardize the regime. To counter this security project, Donnersmarck presents us with characters who display a fundamentally human care that is instigated by governmental practices and yet ultimately works against state-oriented securitization and legitimation." (author's abstract

    Extemporalia - Music, Philology, and Nietzsche’s Misology

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    Os biógrafos de Nietzsche geralmente basearam sua mudança para a filosofia no abandono da filologia acadêmica. As frequentes declarações dos filósofos de suspeita em relação à linguagem verbal – a misologia de Nietzsche – parece confirmar então essa mudança decisiva. No entanto, se alguém considerar, ao invés disso, a obra filosófica como mais contínua aos estudos filológicos prévios, pode-se considerar a preocupação incansável de Nietzsche com a escrita, tanto filológica como filosófica, primeiro como renúncia e depois como redescoberta de suas aspirações musicais. Depois de explorar o envolvimento inicial de Nietzsche com a música, o seguinte artigo centra-se nas reflexões sobre ritmo e música do jovem professor, as quais parecem referir-se ao seu desejo de uma filologia mais musical e subsequentemente uma filosofia musicalmente mais perspicaz. Mas, o que exatamente deveria vincular uma filologia musical? O que significa precisamente emprestar “um ouvi sutil e paciente” para a filosofia
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