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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.
181

<b>Molecular investigation of the multi-phase photochemistry of environmental aquatic systems</b>

Maria V Misovich (17553087) 08 December 2023 (has links)
<p dir="ltr">The chemical constituents of terrestrial and atmospheric waters originate from biomass burning, fertilizer runoff, and anthropogenic activity, among other sources, and their multi-phase chemistry is complex. Sunlight plays an essential role in aquatic chemistry. Photosensitizers in terrestrial and atmospheric waters absorb light to form highly reactive species such as triplet excited carbon (<sup>3</sup>C*), hydroxyl radical (•OH), and singlet oxygen (<sup>1</sup>O<sub>2</sub>), driving the photochemical transformations of dissolved organic matter (DOM) in the aqueous phase. Of note, these reactive species transform DOM compounds that do not undergo direct photolysis. DOM frequently undergoes a change in optical properties following photochemical processing, with implications for air quality, water quality, and human and animal health. The presence of inorganic minerals, such as the fertilizer compound struvite, in terrestrial or atmospheric waters introduces further complexity and impacts the photochemical processes that occur. Simplified proxy systems are created in the laboratory to simulate aquatic photochemical processes and evaluate the formation and/or photodegradation of photoproducts. These mixtures typically consist of a representative organic carbon (OC) compound and a photosensitizer, along with struvite or another inorganic mineral.</p>
182

Impact of Fabrication Processes of Small-Molecule-Doped Polymer Thin-Films on Room-Temperature Phosphorescence

Thomas, Heidi, Haase, Katherina, Achenbach, Tim, Bärschneider, Toni, Kirch, Anton, Talnack, Felix, Mannsfeld, Stefan C. B., Reineke, Sebastian 18 April 2024 (has links)
The development of organic materials displaying room-temperature phosphorescence is a research field that has attracted more and more attention in the last years. Most studies focus on designing or optimizing emitter molecules to increase the phosphorescent performance in host:emitter systems. Rarely, the overall thin-film preparation routines are compared with respect to their triplet-state luminescence yield. Herein, different film preparation techniques are investigated using the very same emitter molecule. A variation of host polymer, post-annealing temperature, and fabrication procedure is evaluated with respect to the obtained phosphorescent lifetime, photoluminescent quantum yield, and phosphorescence-to-luminescence ratio. This study elaborates the importance of different film preparation techniques and gathers a concise set of data which is helpful to anyone optimizing the phosphorescence of a particular system.
183

Fonctionnement tribologique des articulations synoviales pathologiques : rôle des interfaces phospholipidiques

Corneci, Magdalena 21 September 2012 (has links) (PDF)
Afin d'améliorer l'efficacité des traitements des pathologies articulaires, en tenant compte de leur complexité et de leur ampleur, des études récentes ont mis en évidence le rôle des assemblages lipidiques associés à la structure discontinue du fluide synovial dans le contrôle du fonctionnement tribologique articulaire. Ceci à conduit à la mise au point d'un modèle tribologique ex vivo (thèse AM Sfarghiu, 2006), proposant un " motif élémentaire " de la biolubrification articulaire, constitué de l'empilement d'interfaces phospholipidiques et de couches aqueuses. En utilisant ce modèle, l'objectif de ce travail a été d'étudier l'évolution des interfaces phospholipidiques du fluide synovial en présence de pathologies. Pour ce faire, une méthodologie nano-bio-tribologique alliant des analyses biochimiques, physicochimiques, nano-mécaniques et tribologiques a été utilisée. Les résultats de ces analyses montrent : l'influence de la faible rugosité des surfaces frottantes caractérisant les stades précoces des pathologies et celle des propriétés des interfaces phospholipidiques (liées à la variation de leur composition) sur la résistance mécanique, l'évolution au cours du frottement et la dégradation in situ des assemblages lipidiques des fluides synoviaux pathologiques. Le comportement des assemblages lipidiques est accentué par l'action des enzymes associées aux pathologies. Par conséquent, le fonctionnement articulaire dépend de la résistance mécanique des interfaces phospholipidiques et pour obtenir des coefficients de frottement très bas, l'accommodation de vitesse doit s'effectuer au niveau des couches d'hydratation qui entourent les ions présents dans la couche aqueuse. Ces résultats permettront de comprendre à court terme l'évolution des interfaces phospholipidiques dans les pathologies articulaires et, à plus long terme le bon enchaînement cause/conséquence responsable d'une pathologie articulaire afin de développer des traitements plus efficaces, ciblés et non prothétiques.
184

Analiza problema višeplodnih trudnoća nastalih vantelesnom oplodnjom / Problem analysis of multiple pregnancies conceived by in vitro fertilization

Ilić Đorđe 18 February 2015 (has links)
<p>Uvod: Vi&scaron;eplodne trudnoće se javljaju u 1,5% svih trudnoća nakon spontane koncepcije, dok nakon postupaka vantelesne oplodnje ovaj postotak u Evropi iznosi preko 20% uz velike varijacije među zemljama. U na&scaron;oj sredini, stopa vi&scaron;eplodnih trudnoća nakon postupaka vantelesne oplodnje iznosi daleko iznad 30%. Pojava hipertenzivnog sindroma u trudnoći, gestacijskog dijabetesa, operativnog zavr&scaron;avanja trudnoće, prevremenog porođaja, male porođajne telesne mase, neurolo&scaron;kih sekvela kod rođene dece i gotovo svih drugih komplikacija po majku i plod, kao i celokupno opterećenje zdravstvenog sistema vi&scaron;estruko su veći kod vi&scaron;eplodnih u odnosu na jednoplodne trudnoće i udeo navednih komplikacija raste sa brojem plodova. Sa druge strane deca iz postupaka vantelesne oplodnje čine i do 4,5% sve živorođene dece u pojedinim zemljama, &scaron;to uz činjenicu da infertilitet pogađa 16-18% parova u na&scaron;oj sredini daje ovoj pojavi posebnu dimenziju i činije i dru&scaron;tvenim problemom. Perinatalni ishodi trudnoća iz postupaka vantelesne oplodnje su u velikoj meri kompromitovani visokom stopom multiplih trudnoća, koje se danas smatraju komplikacijom, a ne uspehom postupaka vantelesne oplodnje. Jednoplodne trudnoće iz postupaka vantelesne oplodnje u većim studijama pokazuju diskretno slabije perinatalne ishode u odnosu na one spontano začete, dok kod vi&scaron;eplodnih trudnoća ova korelacija nije jasno izražena i dokumentovana, uz prisutnu dilemu da li je vi&scaron;eplodnost sama po sebi ili način koncepcije glavni problem u zapaženoj pojavi. Cilj rada: Uporediti perinatalne ishode vi&scaron;eplodnih trudnoća nastalih postupcima vantelesne oplodnje i spontano začetih kao i perinatalne ishode jednoplodnih i vi&scaron;eplodnih trudnoća iz postupaka vantelesne oplodnje. Pored navdenog cilj rada je i ukazati sveobuhvatnost navedenog problema i na moguća re&scaron;enja za smanjenje njihove učestalosti. Materijal i metode: Kombinacijom retrospektivne opservacione studije i prospektivne longitudinalne kohortne studije u periodu analizom perinatalnih ishoda pacijentkinja porođenih na Klinici za ginekologiju i aku&scaron;erstvo Kliničkog centra Vojvodine u periodu od od 01.01.2008. do 31.12.2010. godine, studija je analizirala i poredila perinatalne ishode kod 174 spontano začete vi&scaron;eplodne trudnoće, 163 vi&scaron;eplodne trudnoće nastale postupkom vantelesne oplodnje, kao i 155 jednoplodnih trudnoća začete postupkom vantelesne oplodnje. Analizirani parametric bili su telesna masa novorođenčeta, dostignuta gestacijska starost, vrednosti Apgar skora, učestalost hipertenzivnog sindroma kod majke i brojni drugi parametri perinatalnog ishoda. Uzeti od strane obučenih kliničara i uno&scaron;eni u posebno dizajniranu bazu podataka, rezultati su statistički analizirani u program JMP ver 9.0 (SAS publisher) uz kori&scaron;ćenje ANOVA analize za testiranje statističke značajnosti između srednjih vrednosti kontinuiranih varijabli, dok je statistička značajnost razlike učestalosti kategorijskih varijabli je određivana Pearsonovim &chi;2 testom. Rezultati: Jednoplodne ART trudnoće uz prosečnu starost od 33,5 godine, prosečnu gestacijsku starost na porođaju od 38,26 gn, udeo prevremenih porođaja od 12,9%, prosečnu telesnu masu od 3258 g, AS u prvom minutu od 8,35 i u petom minutu od 9,2, stopu carskog reza od 65,81%, udeo GDM-a od 7,1%, anemije od 41,94% i preeklampsije od 4,52%, ima sve relevantne parametre perinatalnog ishoda statistički značajno (p&lt;0.0001) superiornije od kako ART tako i non ART blizanačkih trudnoća. ART blizanačke trudnoće pokazale su prosečnu starost majke od 32,9 godina, prosečnu gestacijsku starost na porođaju od 35,6 gn, udeo prevremenih porođaja od 58,27%, prosečnu telesnu masu od 2374 g, AS u prvom minutu od 7,45 i u petom minutu od 8,65, stopu carskog reza od 83,7%, udeo GDM-a od 15,11%, anemije od 78,42% i preeklampsije od 12,23%, dok su non ART blizanačke trudnoće pokazale prosečnu starost majke od 28,8 godina, prosečnu gestacijsku starost na porođaju od 36,08 gn, udeo prevremenih porođaja od 49,71%, prosečnu telesnu masu od 2433 g, AS u prvom minutu od 7,75 i u petom minutu od 8,75, stopu carskog reza od 58,33%, udeo GDM-a od 7,02%, anemije od 67,84% i preeklampsije od 11,11%. Pored godina majke i udela carskog reza koji su bili vi&scaron;i u ART blizanačkim trudnoćama (&lt;0.0001), kao i blago veće pojavi poremećaja količine plodove vode (p=0,033), gotovo svi ostali pokazatelji toka i ishoda trudnoće bili su komparabilni u navedenim grupama. Diskusija i zaključak: Studija je pokazala da su tok i ishod vi&scaron;eplodnih trudnoća nastalih spontano i postupcima vantelesne oplodnje ekvivalentni u gotovo svim pokazateljima uz sličnu prosečnu telesnu masu i gestacijsku starost novorođenčadi, kao i da su svi navedeni parametri ovih vi&scaron;eplodnih trudnoća bez obzira na način koncepcije upadljivo i podjednako lo&scaron;iji u poređenju sa jednoplodnim trudnoćama iz postupka vantelesne oplodnje. Izuzimajući vi&scaron;eplodnost kao factor rizika deca iz postupaka vantelesne oplodnje su generalno zdrava. Sama vi&scaron;eplodnost, a ne način koncepcije predstavljaju problem, koje se sa pravom smatra najvećom komplikacijom vantelesne oplodnje. Dodatna analiza iskustava drugih zdravstvenih sistema ukazuje da jedino &scaron;iroka i sveobuhvatna implementacija strategije vraćanja samo jednog embriona (Single embryo transfer &ndash; SET) može da dovede do smanjivanje stope multiplih trudnoća nakon postupaka vantelesne oplodnje, i sledstvenih komplikacija, a bez ugrožavanja samog uspeha vantelesne oplodnje. Iskustva drugih zdravstvenih sistema ukazuju da je uspe&scaron;na implementacija SET-a jedino moguća uz angažovanje celog dru&scaron;tva, zajedno sa brojnim legislativnim merama iz domena nadzora, kontrole i finansiranja postupaka vantelesne oplodnje. Obim i način finansiranja postupaka vantelesne oplodnje od strane države (uz vi&scaron;e besplatnih poku&scaron;aja za infertilne parove) uz obaveznu upotrebu SET-a, i sistema krioprezervacije na osnovu primera iz prakse predstavlja ključ u borbi za smanjenje problema vi&scaron;eplodnih trudnoća nakon postupaka vantelesne oplodnje.</p> / <p>Introduction: Multiple pregnancies occur in 1.5% of all pregnancies after spontaneous conception and in more than 20 % of all pregnancies concieved after assisted reproductive technologies in Europe, with large variations between countries. In our setting, the rate of multiple pregnancies after the ART is well above 30%. The occurrence of hypertensive syndrome in pregnancy, gestational diabetes, operative delivery, premature birth, low birth weight, neurological and developmental impairment in children, and almost all the other complications for the mother and fetus, as well as the entire burden of the health system are several times higher in multiple pregnancies compared with singleton pregnancies. Incidence of&nbsp; forementioned complications rises with number of fetuses. On the other hand, children from in vitro fertilization procedures make up 4.5% of all live births in some countries, which together with the fact that infertility affects aproximately 16-18% of couples in our country gives an extra dimension to this phenomenon and makes it not just medical but wider social problem. Perinatal outcomes of pregnancies after assisted reproductive technologies (ART) are greatly compromised by the high rate of multiple pregnancies, which are now considered to be a complication rather than success of ART procedures. ART Singleton pregnancies have, in larger studies, show discretely lower perinatal outcomes compared with those conceived spontaneously, while for the multiple pregnancies, this correlation is not clearly expressed and documented. There remains dilemma whether multiplicity itself or the way of conception (ART vs. non ART) constitutes a major problem in the observed differences regarding perinatal outcome of ART pregnancies. Objective: To compare the perinatal outcomes of multiple pregnancies conceived by In vitro fertilization (IVF) and spontaneously and perinatal outcomes of IVF conceived singleton and multiple pregnancies. Additional aim of this thesis is to point out the complexity of this problem and offer possible solutions. Materials and Methods: Design of a study was a combination of retrospective and prospective observational longitudinal cohort study. Analysis included pregnancies which had delivery at the Department of Gynecology and Obstetrics, Clinical Center of Vojvodina in the period from 1.01.2008. to 31.12.2010. The study analyzed and compared the perinatal outcomes in 174 spontaneous conceived multiple pregnancies, 163 multiple pregnancies resulting from IVF procedures, and 155 singleton pregnancies conceived by IVF procedure. Analyzed parameters were newborns birth weight, gestational age at delivery, the value of the Apgar score, occurrence of hypertensive syndrome in pregnancy, gestational diabetes, as well as numerous parameters of perinatal outcome. Taken by trained clinicians and were entered into a specially designed database, the results were statistically analyzed in JMP ver 9.0 software (SAS publisher) using ANOVA analysis to test the statistical significance between the mean values of continuous variables, while the statistical significance of the difference in frequency of categorical variables was assessed by Pearsons &chi;2 test. Results: ART singleton pregnancies had an average mothers age of 33.5 years, the average gestational age at birth of 38.26 gestational weeks (gw), preterm delivery rate of 12.9%, average birth weight 3258 g, Apgar score (AS) in the first minute 8.35, and in the fifth minute 9.2, cesarean section rate 65.81%, Gestational diabetes (GDM) in 7.1% pregnancies, anemia occurred in 41.94% of pregnancies, while preeclampsia was observed in 4.52% of all pregnancies. All relevant parameters of perinatal outcome were significantly (p&lt;0.0001) superior to both ART and non-ART twin pregnancies. ART twin pregnancy showed the average mothers age of 32.9 years, the average gestational age at birth of 35.6 gw, the preterm delivery rate 58.27%, the average body weight newborns 2374 g, AS in the first minute of 7.45, and in the fifth minute of 8.65, the cesarean section rate of 83.7%, GDM in 15.11% of all pregnancies, anemia occurred in 78.42% and preeclampsia in 12.23% of pregnancies, while the non-ART twin pregnancy showed an average mothers age of 28.8 years, the average gestational age at birth of 36.08 gw, the preterm delivery rate of 49.71%, the average body weight of 2433 g, AS in the first minute of 7.75 in the fifth minute 8.75, the caesarian section rate of 58.33%, GDM-a occurred in 7.02%, anemia in 67.84% and preeclampsia in 11.11% of pregnancies. Except for maternal age and the caesarean section rate, which were significantly higher in ART twin pregnancies (p&lt;0.0001), as well as small increase in proportion of amniotic fluid volume disorders (p = 0.033), almost all other parameters of perinatal outcome of were comparable in these groups. Discussion and Conclusion: The study showed that the course and outcome of multiple pregnancies conceived spontaneous and after IVF procedures are equivalent in almost all parameters with similar average body weight and gestational age at birth, and that all these parameters of multiple pregnancies regardless of the conception mode are equally worse compared with singleton pregnancies from IVF procedures. With the exception of multiplicity as a risk factor children from in vitro fertilization procedures are generally healthy. Multiplicity itself and not the mode of conception presented a problem, which is rightly considered the major complication of IVF today. Additional analysis of the experiences of other health system indicates that only a broad and comprehensive implementation of strategy to return only one embryo (SET&ndash;single embryo transfer) can lead to a reduction of the rate of multiple pregnancies after IVF procedures, and the accompanying complications, without compromising IVF success. The experience of other health systems indicate that a successful implementation of SET is only possible with the involvement of the whole society, along with a number of legislative measures in the field of monitoring, control and reimbursement of assisted reproduction procedures. The scope and funding of an IVF procedures (with more free attempts for infertile couples, reimbursed by public health) with mandatory use of SET, and good cryopreservation programs are, based on examples in other countries who had successfully dealt with his problem, is the key in reducing the problem of multiple pregnancies after IVF procedures.</p>
185

Hardwarová akcelerace algoritmu pro hledání podobnosti dvou DNA řetězců / Hardware Acceleration of Algorithms for Approximate String Matching

Nosek, Ondřej January 2007 (has links)
Methods for aproximate string matching of various sequences used in bioinformatics are crucial part of development in this branch. Tasks are of very large time complexity and therefore we want create a hardware platform for acceleration of these computations. Goal of this work is to design a generalized architecture based on FPGA technology, which can work with various types of sequences. Designed acceleration card will use especially dynamic algorithms like Needleman-Wunsch and Smith-Waterman.

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