992 resultados para 02231858 TM-6
Resumo:
The high-temperature paraelectric phase of dicalcium lead propionate, DCLP, at 363 ± 5 K is tetragonal, with a = 12.574 (6), c = 17.403 (9) Å, V = 2751.4 Å3, Z = 4 and corresponds to the space group P41212 (or P43212). The thermal expansion curve shows the transition somewhere between 328 and 343 K.
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Vilsmeier reaction on a few representative 6- and 7-methoxy-1- and 2-tetralones has been investigated. While 1-tetralones give the corresponding 1-chloro-2-formyl3, 4-dihydronaphthalenes, the 2-tetralones afford 1,3-bisformyl-2-chloronaphthalenes. Spectral characteristics of all the products obtained are given and a mechanistic proposal has been made to explain the observed chlorobisformylation.
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Many active pharmaceutical ingredients (APIs) have both anhydrate and hydrate forms. Due to the different physicochemical properties of solid forms, the changes in solid-state may result in therapeutic, pharmaceutical, legal and commercial problems. In order to obtain good solid dosage form quality and performance, there is a constant need to understand and control these phase transitions during manufacturing and storage. Thus it is important to detect and also quantify the possible transitions between the different forms. In recent years, vibrational spectroscopy has become an increasingly popular tool to characterise the solid-state forms and their phase transitions. It offers several advantages over other characterisation techniques including an ability to obtain molecular level information, minimal sample preparation, and the possibility of monitoring changes non-destructively in-line. Dehydration is the phase transition of hydrates which is frequently encountered during the dosage form production and storage. The aim of the present thesis was to investigate the dehydration behaviour of diverse pharmaceutical hydrates by near infrared (NIR), Raman and terahertz pulsed spectroscopic (TPS) monitoring together with multivariate data analysis. The goal was to reveal new perspectives for investigation of the dehydration at the molecular level. Solid-state transformations were monitored during dehydration of diverse hydrates on hot-stage. The results obtained from qualitative experiments were used to develop a method and perform the quantification of the solid-state forms during process induced dehydration in a fluidised bed dryer. Both in situ and in-line process monitoring and quantification was performed. This thesis demonstrated the utility of vibrational spectroscopy techniques and multivariate modelling to monitor and investigate dehydration behaviour in situ and during fluidised bed drying. All three spectroscopic methods proved complementary in the study of dehydration. NIR spectroscopy models could quantify the solid-state forms in the binary system, but were unable to quantify all the forms in the quaternary system. Raman spectroscopy models on the other hand could quantify all four solid-state forms that appeared upon isothermal dehydration. The speed of spectroscopic methods makes them applicable for monitoring dehydration and the quantification of multiple forms was performed during phase transition. Thus the solid-state structure information at the molecular level was directly obtained. TPS detected the intermolecular phonon modes and Raman spectroscopy detected mostly the changes in intramolecular vibrations. Both techniques revealed information about the crystal structure changes. NIR spectroscopy, on the other hand was more sensitive to water content and hydrogen bonding environment of water molecules. This study provides a basis for real time process monitoring using vibrational spectroscopy during pharmaceutical manufacturing.
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Fumonisin B1 (FB1) is a mycotoxin produced by the fungus Fusarium verticillioides, which commonly infects corn and other agricultural products. Fusarium species can also be found in moisture-damaged buildings, and therefore there may also be human exposure to Fusarium mycotoxins, including FB1. FB1 affects the metabolism of sphingolipids by inhibiting the enzyme ceramide synthase. It is neuro-, hepato- and nephrotoxic, and it is classified as possibly carcinogenic to humans. This study aimed to clarify the mechanisms behind FB1-induced neuro- and immunotoxicity. Four neural and glial cell lines of human, rat and mouse origin were exposed to graded doses of FB1 and the effects on the production of reactive oxygen species, lipid peroxidation, intracellular glutathione levels, cell viability and apoptosis were investigated. Furthermore, the effects of FB1, alone or together with lipopolysaccharide (LPS), on the mRNA and protein expression levels of different cytokines and chemokines were studied in human dendritic cells (DC). FB1 induced oxidative stress and cell death in all cell lines studied. Generally, the effects were only seen after prolonged exposure at 10 and 100 µM of FB1. Signs of apoptosis were also seen in all four cell lines. The sensitivities of the cell lines used in this study towards FB1 may be classified as human U-118MG glioblastoma > mouse GT1-7 hypothalamic > rat C6 glioblastoma > human SH-SY5Y neuroblastoma cells. When comparing cell lines of human origin, it can be concluded that glial cells seem to be more sensitive towards FB1 toxicity than those of neural origin. After exposure to FB1, significantly increased levels of the cytokine interferon-γ (IFNγ) were detected in human DC. This observation was further confirmed by FB1-induced levels of the chemokine CXCL9, which is known to be regulated by IFNγ. During co-exposure of DC to both LPS and FB1, significant inhibitions of the LPS-induced levels of the pro-inflammatory cytokines interleukin-6 (IL-6) and IL-1β, and their regulatory chemokines CCL3 and CCL5 were observed. FB1 can thus affect immune responses in DC, and therefore, it is rather likely that it also affects other types of cells participating in the immune defence system. When evaluating the toxicity potential of FB1, it is important to consider the effects on different cell types and cell-cell interactions. The results of this study represent new information, especially about the mechanisms behind FB1-induced oxidative stress, apoptosis and immunotoxicity, as well as the varying sensitivities of different cell types towards FB1.
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Mr=300.33 , triclinic, P1, a=5.635 (2), b=11.077(2), c=11.582(2)A, a= 70.48 (1), fl= 88.16 (3), y=80.56(3) ° , V= 670.325 A3, Z=2, D x = 1.49 Mg m -3, Cu Ka, n= 1.54184 ,A, g = 2.308mm -1, F(000)=316, T=301K, R=0.054, R w = 0.093 for 1944 observed counter reflections. The sulphur position with respect to the dihydrouracil ring, which is of possible relevance to the action of thymidylate synthetase, is axial in molecule A and equatorial in B. Both molecules show the anti conformation about the glycosidic bond [torsion angle C(6)-N(1)-C(1')-O(4'), 2'CN = 21.6 (9) and 29.4 (10) °] and have the C(4')-endo, O(4')-exo (40T) sugar conformation. The dioxolane-ring conformation is O(2')-endo in A and C(7)-endo in B. The dihydrouracil rings show self base pairing with hydrogen bondsN(3A)...O(ZB) and N(3B)...O(ZA).
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C13HlsN205 S, M r = 314.35, orthorhombic, P212121 with a = 39.526 (4), b = 6.607 (2), c = 5.661 (2) A, Z = 4, V = 1478.36 A 3, D c = 1.412 Mg m -3, Cu Ka radiation. Final R = 0.073 for 1154 observed counter reflections. The sulphur atom is in a pseudo-equatorial position with respect to the dihydrouracil ring. The sugar pucker is predominantly O(l')-exo unlike the C(3')-exo,C(4')-endo observed for 2',3'-O-isopropylideneuridine (ISPU). The fivemembered dioxolane ring has C(7) displaced by 0.497 (7)A from the best plane through atoms 0(2'), C(2'), C(3'), 0(3'), in contrast to ISPU where 0(3') shows the maximum deviation.
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The Zeeman effect of chlorine nuclear quadrupole resonance in polycrystalline samples of 2,6-, 2,5 and 3,5-dichlorophenol has been investigated at room temperature in order to study the effect of hydrogen bonding on the electric field gradient asymmetry parameter n. While the two n.q.r. lines in 3,5-dichlorophenol gave an asymmetry parameter of 10%, those in 2,6- and 2,5-dichlorophenol gave different values of n for the two chlorines. The chlorine atom which is ortho to the OH group and involved in hydrogen bonding (i.e., corresponding to the low frequency line) gave an asymmetry parameter of 0.21 in 2,6-dichlorophenol and 0.17 in 2,5-dichlorophenol while the other chlorine (i.e., corresponding to the high frequency line) gave a lower value of 0.12 in 2,6-dichlorophenol and 0.11 in 2,5-dichlorophenol. These values of n are discussed in terms of hydrogen bonding and bond parameters.
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This dissertation is a synchronic description of the phonology and grammar of two dialects of the Rajbanshi language (Eastern Indo-Aryan) as spoken in Jhapa, Nepal. I have primarily confined the analysis to the oral expression, since the emerging literary form is still in its infancy. The grammatical analysis is therefore based, for the most part, on a corpus of oral narrative text which was recorded and transcribed from three informants from north-east Jhapa. An informant, speaking a dialect from south-west Jhapa cross checked this text corpus and provided additional elicited material. I have described the phonology, morphology and syntax of the language, and also one aspect of its discourse structure. For the most part the phonology follows the basic Indo-Aryan pattern. Derivational morphology, compounding, reduplication, echo formation and onomatopoeic constructions are considered, as well as number, noun classes (their assignment and grammatical function), pronouns, and case and postpositions. In verbal morphology I cover causative stems, the copula, primary and secondary agreement, tense, aspect, mood, auxiliary constructions and non-finite forms. The term secondary agreement here refers to genitive agreement, dative-subject agreement and patient (and sometimes patient-agent) agreement. The breaking of default agreement rules has a range of pragmatic inferences. I argue that a distinction, based on formal, semantic and statistical grounds, should be made between conjunct verbs, derivational compound verbs and quasi-aspectual compound verbs. Rajbanshi has an open set of adjectives, and it additionally makes use of a restricted set of nouns which can function as adjectives. Various particles, and the emphatic and conjunctive clitics are also considered. The syntactic structures studied include: non-declarative speech acts, phrase-internal and clause-internal constituent order, negation, subordination, coordination and valence adjustment. I explain how the future, present and past tenses in Rajbanshi oral narratives do not seem to maintain a time reference, but rather to indicate a distinction between background and foreground information. I call this tense neutralisation .
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Titled "An Essay on Antimetaphoric Resistance", the dissertation investigates what is here being called "Counter-figures": a term which has in this context a certain variety of applications. Any other-than-image or other-than-figure, anything that cannot be exhausted by figuration (and that is, more or less, anything at all, except perhaps the reproducible images and figures themselves) can be considered "counter-figurative" with regard to the formation of images and figures, ideas and schemas, "any graven image, or any likeness of any thing". Singularity and radical alterity, as well as temporality and its peculiar mode of uniqueness are key issues here, and an ethical dimension is implied by, or intertwined with, the aesthetic. In terms borrowed from Paul Celan's "Meridian" speech, poetry may "allow the most idiosyncratic quality of the Other, its time, to participate in the dialogue". This connection between singularity, alterity and temporality is one of the reasons why Celan so strongly objects to the application of the traditional concept of metaphor to poetry. As Celan says, "carrying over [übertragen]" by metaphor may imply an unwillingness to "bear with [mittragen]" and to "endure [ertragen]" the poem. The thesis is divided into two main parts. The first consists of five distinct prolegomena which all address the mentioned variety of applications of the term "counter-figures", and especially the rejection or critique of either metaphor (by Aristotle, for instance) or the concept of metaphor (defined by Aristotle, and sometimes deemed "anti-poetic" by both theorists and poets). Even if we restrict ourselves to the traditional rhetorico-poetical terms, we may see how, for instance, metonymy can be a counter-figure for metaphor, allegory for symbol, and irony for any single trope or for any piece of discourse at all. The limits of figurality may indeed be located at these points of intersection between different types of tropes or figures, and even between figures or tropes and the "non-figurative trope" or "pseudo-figure" called catachresis. The second part, following on from the open-ended prolegomena, concentrates on Paul Celan's poetry and poetics. According to Celan, true poetry is "essentially anti-metaphoric". I argue that inasmuch as we are willing to pay attention to the "will" of the poetic images themselves (the tropes and metaphors in a poem) to be "carried ad absurdum", as Celan invites us to do, we may find alternative ways of reading poetry and approaching its "secret of the encounter", precisely when the traditional rhetorical instruments, and especially the notion of metaphor, become inapplicable or suspicious — and even where they still seem to impose themselves.
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My thesis concerns the notion of existence as an encounter, as developed in the philosophy of Gilles Deleuze (1925 1995). What this denotes is a critical stance towards a major current in Western philosophical tradition which Deleuze nominates as representational thinking. Such thinking strives to provide a stable ground for identities by appealing to transcendent structures behind the apparent reality and explaining the manifest diversity of the given by such notions as essence, idea, God, or totality of the world. In contrast to this, Deleuze states that abstractions such as these do not explain anything, but rather that they need to be explained. Yet, Deleuze does not appeal merely to the given. He sees that one must posit a genetic element that accounts for experience, and this element must not be naïvely traced from the empirical. Deleuze nominates his philosophy as transcendental empiricism and he seeks to bring together the approaches of both empiricism and transcendental philosophy. In chapter one I look into the motivations of Deleuze s transcendental empiricism and analyse it as an encounter between Deleuze s readings of David Hume and Immanuel Kant. This encounter regards, first of all, the question of subjectivity and results in a conception of identity as non-essential process. A pre-given concept of identity does not explain the nature of things, but the concept itself must be explained. From this point of view, the process of individualisation must become the central concern. In chapter two I discuss Deleuze s concept of the affect as the basis of identity and his affiliation with the theories of Gilbert Simondon and Jakob von Uexküll. From this basis develops a morphogenetic theory of individuation-as-process. In analysing such a process of individuation, the modal category of the virtual becomes of great value, being an open, indeterminate charge of potentiality. As the virtual concerns becoming or the continuous process of actualisation, then time, rather than space, will be the privileged field of consideration. Chapter three is devoted to the discussion of the temporal aspect of the virtual and difference-without-identity. The essentially temporal process of subjectification results in a conception of the subject as composition: an assemblage of heterogeneous elements. Therefore art and aesthetic experience is valued by Deleuze because they disclose the construct-like nature of subjectivity in the sensations they produce. Through the domain of the aesthetic the subject is immersed in the network of affectivity that is the material diversity of the world. Chapter four addresses a phenomenon displaying this diversified indentity: the simulacrum an identity that is not grounded in an essence. Developed on the basis of the simulacrum, a theory of identity as assemblage emerges in chapter five. As the problematic of simulacra concerns perhaps foremost the artistic presentation, I shall look into the identity of a work of art as assemblage. To take an example of a concrete artistic practice and to remain within the problematic of the simulacrum, I shall finally address the question of reproduction particularly in the case recorded music and its identity regarding the work of art. In conclusion, I propose that by overturning its initial representational schema, phonographic music addresses its own medium and turns it into an inscription of difference, exposing the listener to an encounter with the virtual.
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This dissertation analyzes the interrelationship between death, the conditions of (wo)man s social being, and the notion of value as it emerges in the fiction of the American novelist Thomas Pynchon (1937 ). Pynchon s present work includes six novels V. (1963), The Crying of Lot 49 (1966), Gravity s Rainbow (1973), Vineland (1990), Mason & Dixon (1997), Against the Day (2006) and several short stories. Death constitues a central thematic in Pynchon s work, and it emerges through recurrent questions of mortality, suicide, mass destruction, sacrifice, afterlife, entropy, the relationship between the animate and the inanimate, and the limits of representation. In Pynchon, death is never a mere biological given (or event); it is always determined within a certain historical, cultural, and ideological context. Throughout his work, Pynchon questions the strict ontological separation of life and death by showing the relationship between this separation and social power. Conceptual divisions also reflect the relationship between society and its others, and death becomes that through which lines of social demarcation are articulated. Determined as a conceptual and social "other side", death in Pynchon forms a challenge to modern culture, and makes an unexpected return: the dead return to haunt the living, the inanimate and the animate fuse, and technoscientific attempts at overcoming and controlling death result in its re-emergence in mass destruction and ecological damage. The questioning of the ontological line also affects the structuration of Pynchon's prose, where the recurrent narrated and narrative desire to reach the limits of representation is openly associated with death. Textualized, death appears in Pynchon's writing as a sudden rupture within the textual functioning, when the "other side", that is, the bare materiality of the signifier is foregrounded. In this study, Pynchon s cultural criticism and his poetics come together, and I analyze the subversive role of death in his fiction through Jean Baudrillard s genealogy of the modern notion of death from L échange symbolique et la mort (1976). Baudrillard sees an intrinsic bond between the social repression of death in modernity and the emergence of modern political economy, and in his analysis economy and language appear as parallel systems for generating value (exchange value/ sign-value). For Baudrillard, the modern notion of death as negativity in relation to the positivity of life, and the fact that death cannot be given a proper meaning, betray an antagonistic relation between death and the notion of value. As a mode of negativity (that is, non-value), death becomes a moment of rupture in relation to value-based thinking in short, rationalism. Through this rupture emerges a form of thinking Baudrillard labels the symbolic, characterized by ambivalence and the subversion of conceptual opposites.
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The major cuticular hydrocarbons from the cane beetle species Antitrogus parvulus were deduced to be 4,6,8,10,16,18-hexa- and 4,6,8,10,16- pentamethyldocosanes 2 and 3, respectively. Isomers of 2,4,6,8-tetramethylundecanal 27, 36, and 37, derived from 2,4,6-trimethylphenol, were coupled with the phosphoranes 28 and 29 to furnish alkenes and, by reduction, diastereomers of 2 and 3. Chromatographic and spectroscopic comparisons confirmed 2 as either 6a or 6b and 3 as either 34a or 34b.
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The purpose of this study is to analyze and develop various forms of abduction as a means of conceptualizing processes of discovery. Abduction was originally presented by Charles S. Peirce (1839-1914) as a "weak", third main mode of inference -- besides deduction and induction -- one which, he proposed, is closely related to many kinds of cognitive processes, such as instincts, perception, practices and mediated activity in general. Both abduction and discovery are controversial issues in philosophy of science. It is often claimed that discovery cannot be a proper subject area for conceptual analysis and, accordingly, abduction cannot serve as a "logic of discovery". I argue, however, that abduction gives essential means for understanding processes of discovery although it cannot give rise to a manual or algorithm for making discoveries. In the first part of the study, I briefly present how the main trend in philosophy of science has, for a long time, been critical towards a systematic account of discovery. Various models have, however, been suggested. I outline a short history of abduction; first Peirce's evolving forms of his theory, and then later developments. Although abduction has not been a major area of research until quite recently, I review some critiques of it and look at the ways it has been analyzed, developed and used in various fields of research. Peirce's own writings and later developments, I argue, leave room for various subsequent interpretations of abduction. The second part of the study consists of six research articles. First I treat "classical" arguments against abduction as a logic of discovery. I show that by developing strategic aspects of abductive inference these arguments can be countered. Nowadays the term 'abduction' is often used as a synonym for the Inference to the Best Explanation (IBE) model. I argue, however, that it is useful to distinguish between IBE ("Harmanian abduction") and "Hansonian abduction"; the latter concentrating on analyzing processes of discovery. The distinctions between loveliness and likeliness, and between potential and actual explanations are more fruitful within Hansonian abduction. I clarify the nature of abduction by using Peirce's distinction between three areas of "semeiotic": grammar, critic, and methodeutic. Grammar (emphasizing "Firstnesses" and iconicity) and methodeutic (i.e., a processual approach) especially, give new means for understanding abduction. Peirce himself held a controversial view that new abductive ideas are products of an instinct and an inference at the same time. I maintain that it is beneficial to make a clear distinction between abductive inference and abductive instinct, on the basis of which both can be developed further. Besides these, I analyze abduction as a part of distributed cognition which emphasizes a long-term interaction with the material, social and cultural environment as a source for abductive ideas. This approach suggests a "trialogical" model in which inquirers are fundamentally connected both to other inquirers and to the objects of inquiry. As for the classical Meno paradox about discovery, I show that abduction provides more than one answer. As my main example of abductive methodology, I analyze the process of Ignaz Semmelweis' research on childbed fever. A central basis for abduction is the claim that discovery is not a sequence of events governed only by processes of chance. Abduction treats those processes which both constrain and instigate the search for new ideas; starting from the use of clues as a starting point for discovery, but continuing in considerations like elegance and 'loveliness'. The study then continues a Peircean-Hansonian research programme by developing abduction as a way of analyzing processes of discovery.
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Single crystal [(111) and (100) planes], and powder ESR of Mn2+ (substituting for Ca2+) in Ca2Ba(C2H5COO)6 in the temperature range 220°C to -160°C shows (i) a doubling of both the physically and chemically inequivalent sites, and a change in the magnitude (150 G at -6°C to 170 G at -8°C) as well as the orientation of the D tensor across the -6°C transition and (ii) an inflection point in the D vs T plot across the -75°C transition. The oxygen octahedra around the Ca2+ sites are inferred to undergo alternate rotations, showing the participation of the carboxyl oxygens in the -6°C transition. A relation of the type D=D0(1+αT+βT2) seems to fit the D variation satisfactorily.