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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Η δραστηριότητα της β-γλυκουρονίδασης στο εγκεφαλονωτιαίο υγρό παιδιών με οξεία λεμφοβλαστική λευχαιμία

Βλάχα, Βασιλική 12 July 2010 (has links)
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2

Οι από του στόματος κεφαλοσπορίνες πιβοξιλική κεφεταμέτη και ακετυλοκεφουροξίμη στη θεραπεία παιδιατρικών λοιμώξεων

Χαλιώτης, Φώτιος-Χαράλαμπος 13 April 2010 (has links)
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3

Προσδιορισμός της βιοτίνης πλάσματος στη νεογνική ηλικία

Παύλου, Βασιλική 18 May 2010 (has links)
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4

Χορήγηση μεγάλων δόσεων βιταμίνης Α για τη πρόληψη της βρογχοπνευμονικής δυσπλασίας

Παπαγαρουφάλης, Κωνσταντίνος 18 May 2010 (has links)
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5

Αρτηριακή πίεση παιδιών καπνιστριών μητέρων κατά τη νεογνική ηλικία και τον πρώτο χρόνο ζωής

Παναγούλιας, Δημήτριος 19 May 2010 (has links)
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6

Λοίμωξη από chlamydia pneumoniae στα παιδιά

Τρίγκα, Μαρία 19 May 2010 (has links)
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7

Δραστικότητα λυοσωματικών ενζύμων στα λευκά αιμοσφαίρια και το πλάσμα αίματος ασθενών με μεσογειακή αναιμία

Χατίρη, Ειρήνη 09 July 2010 (has links)
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8

Βελτιστοποίηση της έκθεσης του αξονικού τομογράφου σε παιδιατρικές εξετάσεις / Paediatric computed tomography exposure optimization

Τζιωρτζή, Άντρη 15 December 2008 (has links)
The utilization of Computed Tomography in paediatric examinations constantly increases. During the procedure, a high amount of dose is delivered to children, which could be avoided. This study examined whether the selection of scanning parameters – tube voltage and tube current-time product- could be based on patient size instead of patient age or weight aiming, for dose reduction. The SRS78 spectrum processor software was employed to generate spectra with tube voltage between 80kVp and 120kVp and with tube current-time product between 50mAs and 165mAs. These spectra were attenuated by different thicknesses of polymethylmethacrylate (PMMA) phantoms. The simulation technique was validated with experimental measurements acquired on CTDI phantoms on a Siemens Somatom plus 4 scanner. The image quality was assessed in terms of noise, contrast and contrast-to-noise ratio (CNR). Furthermore the contrast of iodine, adipose tissue and cortical-bone relative to muscle were calculated in order to examine how the contrast of different materials was influenced when tube voltage changed. The data analysis shows that there is a definite relationship between image quality and the size of a patient. When exposure settings are kept constant, the level of noise, contrast and Contrast-to-Noise Ratio (CNR) depends on the size of the phantom. Noise is increased exponentially and contrast is reduced linearly as the size of the phantom is increased. CNR is markedly higher in small size phantoms. Moreover, when tube voltage was reduced the noise level was increased less in the small size phantoms and the contrast of high atomic number materials is reduced more when tube voltage is reduced. The CNR for high atomic number materials presents modest improvements when tube voltage is increased therefore examinations with contrast agents could be performed at lower tube voltages. Furthermore the high CNR in small size phantoms could be traded off with lower mAs. In particularly the mAs could be reduced by up to 95% while maintaining the same CNR as for adults resulting in dramatic dose reductions for children. Moreover, since Computed Tomography stands out from all the other X-ray techniques due to its ability to detect structures of similar densities the detect ability of low contrast details was investigated. The Catphan phantom and particularly the CTP515 module was employed. The phantom was scanned with the Siemens Somatom plus 4 scanner at 80kVp, 120kVp and 140kVp and with tube current-time product between 43mAs and 165mAs. The image quality was assessed subjectively and objectively. It is observed that when 120kVp and 140kVp are applied there are not sufficient differences on image quality which justify the selection of 140kVp in paediatric protocols. When 80kVp is applied structures with contrast lower than 10HU are not detected. Concerning mAs does not contribute to the detection of low contrast details except if it is combined with high tube voltages. However, mAs contribute to the visualisation of smaller in size details but above a threshold value, higher mAs does not serve any purpose and the value of 300mAs employ in many protocols is not justified. In conclusion, the reduction of dose during paediatric Computed Tomography examinations is more than probable since scanning parameters could be reduced without degradation of image quality. However in order to assure the reduction of dose without side effects, protocols must be constructed which will individualize the Computed Tomography examinations. That is, the optimum spectrum must be selected relative to the diagnostic task and the size of the patient. / -
9

Φορεία streptococcus pneumoniae κατά την παιδική ηλικία στην Ελλάδα: ορότυποι και αντοχή στα αντιβιοτικά

Κατωπόδης, Γεώργιος Δ. 06 July 2010 (has links)
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10

Διαφλεβική σύγκλειση του ανοικτού αρτηριακού (βοταλείου) πόρου με την τεχνική της διπλής ομπρέλλας rashkind

Τσαούσης, Γεώργιος 16 April 2010 (has links)
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