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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.
571

Insights into the influence of solvent polarity on the crystallization of poly(ethylene oxide) spin-coated thin films via in situ grazing incidence wide angle x-ray scattering

Toolan, D.T.W., Isakova, A., Hodgkinson, R., Reeves-McLaren, N., Hammond, O.S., Edler, K.J., Briscoe, W.H., Arnold, T., Gough, Tim, Topham, P.D., Howse, J.R. 10 February 2016 (has links)
yes / Controlling polymer thin-film morphology and crystallinity is crucial for a wide range of applications, particularly in thin-film organic electronic devices. In this work, the crystallization behavior of a model polymer, poly(ethylene oxide) (PEO), during spincoating is studied. PEO films were spun-cast from solvents possessing different polarities (chloroform, THF and methanol) and probed via in situ grazing incidence wide angle x-ray scattering. The crystallization behavior was found to follow the solvent polarity order (where chloroform < THF < methanol) rather than the solubility order (where THF > chloroform > methanol). When spun-cast from non-polar chloroform, crystallization largely followed Avrami kinetics, resulting in the formation of morphologies comprising large spherulites. PEO solutions cast from more polar solvents (THF and methanol) do not form well-defined highly crystalline morphologies and are largely amorphous with the presence of small crystalline regions. The difference in morphological development of PEO spun-cast from polar solvents is attributed to clustering phenomena that inhibit polymer crystallization. This work highlights the importance of considering individual components of polymer solubility, rather than simple total solubility, when designing processing routes for the generation of morphologies with optimum crystallinities or morphologies.
572

Structures et référence

Merle, Jean-Marie 22 November 2006 (has links) (PDF)
Synthèse des travaux de recherche effectués, sur will + BV, sur le conditionnel français, son invariant sémantique et sa traduction en anglais, sur les repères hypothétiques, l'opposition entre irréel et potentiel, le conditionnel journalistique et le discours indirect libre ; sur certaines constructions verbales (want, will) ; sur le sujet, la prédication, les constructions participiales, la qualification ; sur la focalisation (just ; l'exception) ; sur les prépositions ; sur les mots en wh. Présentation d'une réflexion actuelle qui porte entre autres sur la qualification, les structures résultatives, l'apposition, la coprédication, les nexus, les paradigmatiques, les structures de focalisation. L'auteur en est arrivé à essayer de rendre compte systématiquement dans ses travaux, entre autres, en relation avec la spécificité des phénomènes étudiés, de trois séries d'observables linguistiques dont les propriétés sont loin d'être entièrement explorées : trois modes de repérage - structurel, sémantico-référentiel, énonciatif ; trois incidences fondamentales - prédicative, co-prédicative, interne au syntagme ; trois types de constituants de base - syntagmes, nexus, propositions.
573

Molecular epidemiology of rotavirus infection in Gauteng and the surrounding areas during the 2010 and 2011 seasons

Theron, Elizabeth Maria Charlotte 16 May 2013 (has links)
Rotavirus infection causes acute gastroenteritis in children younger than five years of age, and commonly occurring human rotavirus strains include G1 - G4 and G9 associated with P[4], P[6] and P[8]. In this study, of 6050 stool samples collected from a Private Pathology Practice in Pretoria, March 2010 - August 2011, 664 tested positive using Coris test-strips. Of these samples, 752 were retested using EIA and, results showed: Coris sensitivity was 93,7% and specificity 99,8%; the winter epidemic peaked in July of both years; more males and children under 30 months of age were particularly vulnerable to infections. Rotavirus-positive samples from Trichardt, Rustenburg and Middelburg were analysed by PAGE and RT-PCR showing circulating strains as mainly G8P[4] (60%) with short electropherotypes, G12P[8] (66%) with long electropherotypes, and G1P[8] at low incidence in the 2010/2011 seasons. These results suggest additional research to monitor the impacts of recently introduced rotavirus vaccines on changing strain profiles in South African communities / Life & Consumer Sciences / M.Sc. (Life Sciences)
574

Modelling the effect of HIV on age-specific incidence of active TB disease : a comparison between Taiwan and Cape Town Metropole

Winkler, Dietrich Maximilian Albert 03 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: See full text / AFRIKAANSE OPSOMMING: Sien volteks
575

Low-concentrating, stationary solar thermal collectors for process heat generation

Hess, Stefan January 2014 (has links)
The annual gain of stationary solar thermal collectors can be increased by non-focusing reflectors. Such concentrators make use of diffuse irradiance. A collector’s incidence angle modifier for diffuse (diffuse-IAM) accounts for this utilization. The diffuse irra-diance varies over the collector hemisphere, which dynamically influences the diffuse-IAM. This is not considered by state-of-the-art collector models. They simply calculate with one constant IAM value for isotropic diffuse irradiance from sky and ground. This work is based on the development of a stationary, double-covered process heat flat-plate collector with a one-sided, segmented booster reflector (RefleC). This reflector approximates one branch of a compound parabolic concentrator (CPC). Optical meas-urement results of the collector components as well as raytracing results of different variants are given. The thermal and optical characterization of test samples up to 190 °C in an outdoor laboratory as well as the validation of the raytracing are discussed. A collector simulation model with varying diffuse-IAM is described. Therein, ground reflected and sky diffuse irradiance are treated separately. Sky diffuse is weighted with an anisotropic IAM, which is re-calculated in every time step. This is realized by gener-ating an anisotropic sky radiance distribution with the model of Brunger and Hooper, and by weighting the irradiance from distinct sky elements with their raytraced beam-IAM values. According to the simulations, the RefleC booster increases the annual out-put of the double-covered flat-plate in Würzburg, Germany, by 87 % at a constant inlet temperature of 120 °C and by 20 % at 40 °C. Variations of the sky diffuse-IAM of up to 25 % during one day are found. A constant, isotropic diffuse-IAM would have under-valued the gains from the booster by 40 % at 40 °C and by 20 % at 120 °C. The results indicate that the gain of all non-focusing solar collectors is undervalued when constant, isotropic diffuse-IAMs calculated from raytracing or steady-state test data are used. Process heat generation with RefleC is demonstrated in a monitored pilot plant at work-ing temperatures of up to 130 °C. The measured annual system utilization ratio is 35 %. Comparing the gains at all inlet temperatures above 80 °C, the booster increases the an-nual output of the double-covered flat-plates by 78 %. Taking all inlet temperatures, the total annual gains of RefleC are 39 % above that of the flat-plates without reflectors. A qualitative comparison of the new simulation model results to the laboratory results and monitoring data shows good agreement. It is shown that the accuracy of existing collector models can be increased with low effort by calculating separate isotropic IAMs for diffuse sky and ground reflected irradiance. The highest relevance of this work is seen for stationary collectors with very distinctive radiation acceptance.
576

The Burden of Epilepsy : using population-based data to define the burden and model a cost-effective intervention for the treatment of epilepsy in rural South Africa

Wagner, Ryan G January 2016 (has links)
Rationale Epilepsy is a common, chronic, neurological condition that disproportionately affects individuals living in low- and middle- income countries, including much of sub-Saharan Africa. Epilepsy is treatable, with the majority of individuals who take anti-epileptic drugs experiencing a reduction, or elimination, of seizures. Yet the number of individuals taking and adhering to medication in Africa is low and interventions aimed at improving treatment are lacking. Aims To define the epidemiology of convulsive epilepsy in rural South Africa in terms of incidence, mortality and disability-adjusted life years; to determine outpatient, out-of-pocket costs resulting from epilepsy treatment; to establish the level of adherence to anti-epileptic drugs amongst people with epilepsy; and, to determine whether the introduction of routine visits to people with epilepsy by community health workers is a cost-effective intervention for improving adherence to anti-epileptic drugs. Methods Nested within the Agincourt Health and Demographic Surveillance System, this work utilized a cohort of individuals diagnosed with convulsive epilepsy in 2008 to determine health care utilization and out-of-pocket costs due to care sought for epilepsy. Additionally, using blood samples from the cohort, anti-epileptic drug adherence was measured and, following the cohort, mortality rates were determined. Using these collected epidemiological parameters, disability-adjusted life years due to convulsive epilepsy were determined. Finally, combining the epidemiological and cost parameters, a community health worker intervention was modeled to determine its incremental cost-effectiveness ratio. Key Findings The burden of convulsive epilepsy is lower in rural South Africa than other parts of Africa, likely due to lower levels of known risk factors. Yet the burden, especially in terms of mortality, remains high, as does the treatment gap and health care utilization. Findings from the economic evaluation found the introduction of a community health worker to be highly cost-effective and would likely lower the burden of epilepsy in rural South Africa. Implications Epilepsy contributes to the burden of disease in rural South Africa, with high levels of mortality and a substantial treatment gap. The introduction of a community-health worker is likely to be one cost-effective, community based intervention that would lower the burden of epilepsy by improving adherence to anti-epileptic drugs. Implementing this intervention, based on these findings, is a justified and important next step.
577

Computational workflow management for conceptual design of complex systems : an air-vehicle design perspective

Balachandran, Libish Kalathil January 2007 (has links)
The decisions taken during the aircraft conceptual design stage are of paramount importance since these commit up to eighty percent of the product life cycle costs. Thus in order to obtain a sound baseline which can then be passed on to the subsequent design phases, various studies ought to be carried out during this stage. These include trade-off analysis and multidisciplinary optimisation performed on computational processes assembled from hundreds of relatively simple mathematical models describing the underlying physics and other relevant characteristics of the aircraft. However, the growing complexity of aircraft design in recent years has prompted engineers to substitute the conventional algebraic equations with compiled software programs (referred to as models in this thesis) which still retain the mathematical models, but allow for a controlled expansion and manipulation of the computational system. This tendency has posed the research question of how to dynamically assemble and solve a system of non-linear models. In this context, the objective of the present research has been to develop methods which significantly increase the flexibility and efficiency with which the designer is able to operate on large scale computational multidisciplinary systems at the conceptual design stage. In order to achieve this objective a novel computational process modelling method has been developed for generating computational plans for a system of non-linear models. The computational process modelling was subdivided into variable flow modelling, decomposition and sequencing. A novel method named Incidence Matrix Method (IMM) was developed for variable flow modelling, which is the process of identifying the data flow between the models based on a given set of input variables. This method has the advantage of rapidly producing feasible variable flow models, for a system of models with multiple outputs. In addition, criteria were derived for choosing the optimal variable flow model which would lead to faster convergence of the system. Cont/d.
578

Prediktivni model za nastanak bronhopulmonalne displazije kod novorođenčadi porođajne mase ispod 1500 grama / Predictive model for bronchopulmonary dysplasia in very low birth weight infants

Vilotijević Dautović Gordana 01 October 2015 (has links)
<p>Uvod: Bronhopulmonalna displazija (BPD) je najče&scaron;ća i najteža respiratorna posledica prematuriteta. Utvrđivanje najznačajnijih faktora rizika za nastanak BPD kod novorođenčadi porođajne mase (PM) ispod 1500g može omogućiti procenu rizika za&nbsp; nastanak bolesti i identifikaciju novorođenčadi u visokom riziku, &scaron;to je važno za pružanje informacija roditeljima o prognozi,&nbsp; planiranje preventivnih i terapijskih mera i stratifikovanje novorođenčadi koja su u riziku za sprovođenje budućih istraživanja. Cilj: Utvrđivanje incidencije, stepena težine BPD, smrtnosti, identifikacija najznačajnijih prenatalnih i postnatalnih faktora rizika za nastanak BPD, konstrukcije modela predikcije za nastanak BPD. Materijal i metode: Istraživanje je sprovedeno na 504&nbsp; prevremeno rođene novorođenčadi PM&lt;1500g koja su rođena u porodili&scaron;tima u AP Vojvodini i lečena u tercijarnom Centru za neonatologiju i intenzivnu negu i terapiju, na Institutu za zdravstvenu za&scaron;titu dece i omladine Vojvodine u periodu od&nbsp; 2006.-2011. godine. Retrospektivno je analizirano prisustvo BPD, prema stepenima težine, smrtnost. Podaci su izdvojeni iz&nbsp; istorija bolesti za svako novorođenče, 30 potencijalnih prenatalnih i postnatalnih faktora je opisano deskriptivnom i univarijantnom statistikom. Statstički najznačajniji faktori su uneti u multifaktorsku logističku regresionu analizu u cilju&nbsp; konstrukcije prediktivnih modela za nastanak BPD u 1.,14. i 21. danu neonatalnog života. Podaci su obrađeni u StatSoft-ovom&nbsp; programskom paketu Statistica 10.0.&nbsp; Validacija modela predikcije je sprovedena u prospektivnom delu istraživanja, na 100&nbsp;&nbsp;&nbsp; prevremeno rođene novorođenčadi&lt;1500g, u periodu od 2012-2013. godine. Rezultati: U retrospektivnom delu&nbsp; istraživanja,&nbsp; od 504&nbsp; novorođenčeta PM&lt;1500 grama, umrlo je 17.65%, BPD je imalo 45.43% (blagu BPD 19.44%, srednje te&scaron;ku 19.84%,&nbsp; te&scaron;ku&nbsp; 6.15%), srednje te&scaron;ku i&nbsp; te&scaron;ku 25.99%.Antenatalna primena kortikosteroida je zastupljena u 47.02%, surfaktant&nbsp;&nbsp; je&nbsp;&nbsp; primenjen kod 69.78% novorođenčadi. Najznačajniji prenatalni prediktivni faktor rizika za nastanak BPD/smrtnog ishoda je horioamnionitis (OR 5.72; 95% CI 3.42-9.62), dok su protektivni faktori: prenatalna primene kortikosteroida (OR&nbsp; 0.41;&nbsp; 95%CI&nbsp; 0.29-0.60), porođaj carskim rezom (OR&nbsp; 0.24; 95% CI 0.16-0.36). Najznačajniji&nbsp; postnatalni prediktivni faktori rizika su: GS&nbsp; (p&asymp;0.00), PM (p&asymp;0.00), reanimacija u porođajnoj sali (OR 7.01; 95% CI 4.12-12.01), rana&nbsp; neonatalna&nbsp; sepsa&nbsp; (OR&nbsp; 7.35;&nbsp; 95%CI&nbsp; 3.79-14.58), RDS&nbsp; (p&asymp;0.00), primena surfaktanta (OR13,3;95%CI 8,2 - 21,67), DAP (OR 4.12; 95%CI&nbsp; 2.47-6.89),&nbsp; dok&nbsp; je&nbsp; ženski&nbsp; pol&nbsp; protektivan (OR&nbsp; 0.61; 95% CI 0.42-0.89). FiO2 i IPPV su u svim posmatranim danima značajni faktori rizika. Primena IPPV u 1. danu (OR 10.71;&nbsp; 95% CI 6.67-17.26); u ostalim danima rizik od BPD raste prema rastućoj invazivnosti respiratorne&nbsp; potpore.&nbsp; Konstruisani su modeli&nbsp; predikcije za 1, 14 i 21. dan života, modeli imaju visoku prediktivnu vrednost: ukupan procenat uspe&scaron;nosti&nbsp; modela je 84.26%-90.80%, modeli sa ne&scaron;to većim uspehom predviđaju&nbsp;&nbsp; prisustvo (85.36%-94.12%), nego odusustvo BPD (81.72-86.56%). OR modela je 28.07-103.04. Modeli su uspe&scaron;no validirani&nbsp; na 102 pacijenta sa ukupnim procentom uspe&scaron;nosti (82-90%), PPV (0.86-0.94) i NPV (0.76-0.87). Zaključak:&nbsp; Kori&scaron;ćenjem&nbsp; prenatalnih i postnatalnih kliničkih podataka moguće je predvideti nastanak BPD ili smrtnog ishoda.</p> / <p>Introduction: Bronchopulmonary dysplasia (BPD) is the most common serious pulmonary morbidity in very low birth weight (VLBW) infants. It is of clinical importance to determine clinical variables that are associated with BPD in order to identify infants who are at risk of developing BPD; it contributes to BPD prevention, may enable prognostic information for parents and future studies design. Objective: The aim of this study was to determine the incidence and severity of BPD, mortality rate in VLBW infants, to identify prenatal and postnatal predictive risk factors for bronchopulmonary dysplasia and competing outcome of death and to develop predictive models. Materials and Methods: Study was conducted in 504 VLBW infants born in the maternity hospitals in Vojvodina and admitted to tertiary Center for newborn and neonatal intensive care at the Institute for Child and Youth Health Care of Vojvodina, from January 2006. to December 2011. Data were retrospectively collected from clinical records for outcomes BPD or death; prenatal and postnatal factors associated with BPD were collected at three postnatal ages and examined by descriptive and univariate statistics; factors that were significantly associated with BPD and/or death were entered into a multivariate logistic regression analysis for develop predictive models. Data were analyzed using StatSoft&#39;s software package Statistica 10.0. Validation of the models were conducted in a prospective study in 102 VLBW infants born from January 2012. to December 2013. Results: There were 504 very low birth weight infants who were eligible for this study, 17.65% died, 45.43% developed BPD (mild BPD 19.44%, moderate 19.84%, severe 6.15%), moderate and severe 25.99%. The mean birth weight for the cohort was 1125.6&plusmn;280.9g, the mean gestation age was GS 28,78&plusmn;3,01, 49.21% were male. Surfactant received 69.78%, antenatal steroids 47.02% newborns. Key risk factors for BPD and/or death were: chorioamnionitis and maternal infections at delivery (OR 5.72; 95% CI 3.42-9.62); protective prenatal factors were: antenatal corticosteroid therapy (OR 0.41; 95%CI 0.29-0.60), cesarean delivery (OR 0.24; 95% CI 0.16-0.36). Postnatal rick factors were: GS (p&asymp;0.00), birth weight (p&asymp;0.00), delivery room resuscitation (OR 7.01; 95% CI 4.12-12.01), early neonatal sepsis (OR 7.35; 95%CI 3.79-14.58), RDS (p&asymp;0.00), surfactant (OR13,3;95%CI 8,2 - 21,67), DAP (OR4.12; 95% CI 2.47-6.89), while female gender was protective (OR 0.61; 95% CI 0.42-0.89). At each time point studied, FiO2 was significantly higher in BPD/death, as well as respiratory support; on the first day invasive respiratory support was significantly associated with BPD/death (IPPV and HFOV) (OR 10.71; 95% CI 6.67-17.26), in other days BPD was associated with increasing invasiveness of respiratory support. In multifactorial logistic regression analysis separately predictive models were developed at three postnatal ages, at 1st, 14th and 21st day. Models had high predictive performance: total success of the models were 84.26% - 90.80%, models successfully predicted the presence of BPD in 85.36% -94.12%, absence of the BPD in 81.72 - 86.56% cases. OR of models were 28.07-103.04. The models were successfully validated on 102 patients with a total percentage of success 82 - 90%, with PPV 0.86-0.94 and NPV 0.76-0.87. Conclusion: Using prenatal and postnatal clinical data it is possible to predict the development of BPD and/or death in very low birth weight infants. It is very important to identify risk factors for BPD development in order to decrease the incidence of BPD and mortality rate.</p>
579

Kretanje utvrđenih profesionalnih zaraznih oboljenja kod radnika na teritoriji Vojvodine / Trends of the established occupational communicable diseases among workers in the territory of Vojvodina

Španović Milorad 22 June 2016 (has links)
<p>Profesionalna infektivna oboljenja nastaju kao posledica izloženosti mikroorganizama u radnoj sredini. Cilj ovog istraživanja je utvrđivanje vrsta profesionalnih &scaron;tetnosti koje dovode do profesionalnih infektivnih oboljenja i njihove incidencije u privrednim delatnostima Autonomne Pokrajine Vojvodine, kao i predloga adekvatnih mera za njihovu prevenciju. Profesionalna infektivna oboljenja su činila 13,4% od ukupno 464 slučaja utvrđenih profesionalnih oboljenja u Autonomnoj Pokrajini Vojvodini u toku dvadesetogodi&scaron;njeg perioda od 1992. do 2011. godine. Od ukupno utvrđenih 62 slučaja profesionalnih infektivnih oboljenja dve trećine su činili profesionalni virusni hepatitisi, 31% profesionalne antropozoonoze i 3% profesionolana tuberkuloza. Dve trećine obolelih od profesionalnih infektivnih bolesti bile su osobe ženskog pola &scaron;to je statistički značajno vi&scaron;e u poređenju sa osobama mu&scaron;kog pola, dok su zaposleni mu&scaron;kog pola činili 57%, a ženskog 43% ukupno zaposlenih na teritoriji Vojvodine. Najče&scaron;ća profesionalna infektivna oboljenja bila su virusni hepatits B 52%, kju groznica 18%, virusni hepatitis C 15%, lajmska bolest 6%, leptospiroza 5%. Utvrđeno je da je do&scaron;lo do statistički značajnog sniženja incidencije profesionalnog virusnog hepatitisa B u<br />periodu nakon dono&scaron;enja odluke o obaveznoj imunizaciji 2002. godine, sa 6,27 na 1,35 na 100.000 zaposlenih, dok nije bilo statistički značajne razlike kada je u pitanju incidencija virusnog hepatitisa C. Profesionalna infektivna oboljenja su u vi&scaron;e od dve trećine slučajeva registrovana kod zdravstvenih radnika (69%) sa prosečnom incidencijom od 5,18 na 100.000 zaposlenih, znatno niža bila je incidencija u proizvodnji prehrambenih proizvoda (1,36) i poljoprivredi sa lovom, ribolovom i &scaron;umarstvom (1,11). Ne&scaron;to vi&scaron;e od trećine radnika bilo je privremeno nesposobno za rad u toku utvrđivanja profesionalnog oboljenja, jer je lečenje bilo u toku. Kod ovih radnika značajno je naknadno oceniti radnu sposobnost i utvrditi eventualne posledice oboljenja. Pored primene specifičnih mera imunizacije ukoliko postoje, kao i ličnih mera za&scaron;tita koje sprečavaju kontakt sa uzročnicima, značajno je sprovođenje edukacije radnika o rizicima i preventivnih lekarskih pregleda radi rane identifikacije obolelih radnika.</p> / <p>Occupational communicable diseases are caused by exposure to microorganism&rsquo;s in working environment. The aim of this study is to determine the types of occupational hazards that lead to occupational communicable diseases and their incidence in the economic activities of the Autonomous Province of Vojvodina, as well as the proposal of adequate measures for their prevention. Occupational communicable diseases accounted for 13.4% of the total of 464 cases of occupational diseases identified in the Autonomous Province of Vojvodina during the twenty-year period from 1992 to 2011. In the total of 62 identified cases of occupational communicable diseases, occupational viral hepatitis accounted for two-thirds, occupational anthropozoonoses for 31%, occupational tuberculosis for 3%. Two-thirds of patients with occupational communicable diseases were females, significantly more compared to male, while male accounted for 57% and female for 43% of the total employees in Vojvodina. The most frequent occupational communicable diseases were viral hepatitis B 52%, Q fever 18%, viral hepatitis C 15%, Lyme disease 6%, leptospirosis 5%. It was found that there was a statistically significant decrease in the incidence of occupational viral hepatitis B in the period after the decision on obligatory immunization in 2002, from 6.27 to 1.35 per 100,000 employees, while there were no statistically significant differences in the incidence of viral hepatitis C. In more than two-thirds of the cases occupational communicable diseases were registered in health care workers (69%) with the average incidence of 5.18 per 100,000 employees, substantially lower the incidence was in the production of food (1.36), as well as in agriculture, hunting, fishing and forestry (1.11). Just over a third of workers were temporarily unable to work during the verification of occupational disease due to the ongoing treatment. In these workers it is important to assess working ability afterwards and identify the possible consequences of the disease. In addition to the application of specific measures of immunization if any available, as well as personal protection measures that prevent contact with pathogens it is important to implement risk education of workers and preventive medical examinations for early identification of affected employees.</p>
580

Detekcija intervalnih malignih i premalignih lezija debelog creva kod bolesnika sa urednim nalazom na inicijalnoj kolonoskopiji / Detection of malignant and premalignant colon lesions in patients with clear colon on first colonoscopy

Kukić Biljana 28 September 2016 (has links)
<p>UVOD: Kolorektalni karcinom je na trećem mestu po učestalosti oboljevanja od svih karcinoma uz porast incidencije CRC u visoko razvijenim zemljama.70% obolelih od CRC je starije od 65 godina uz veću incidenciju proksimalnih karcinoma u odnosu na distalne u svim uzrasnim grupama i kod oba pola. Smatra se da bi 66-75% slučajeva CRC moglo biti izbegnuto zdravim načinom života. 75% CRC nastaje iz adenomatoznih preko polip kancer sekvence i da vi&scaron;e od 90% adenoma neće progredirati u karcinom. U studijama skrining kolonoskopija prijavljeno je 6-12% neviđenih velikih polipa i ko 5% CRC na inicijalnom kolonoskopskom pregledu. Postoperativne periodične kolonoskopije nakon operacije kolorektalonog karicinoma imaju za cilj otkrivanje metahronih carcinoma polipa kao pojavu bolesti na anastomozi ali nije dokazani benefit u preživljavanju bolesnika koji su imali učestalije postoperativne kolonoskopije (na godinu dana) u odnosu na one koji su praćenina 3 ili 5 godina. CILJEVI ISTRAŽIVANJA: Prospektivno ispitivanje pojave intervalnih lezija kolona (malignih i premalignih) u periodu od 2-7 godine od prve negativne kolonoskopije bez obzira na razlog pregleda. Ispitivanje razlike u životnim navikama između ispitanika u zavisnosti od nalaza na ponovljenoj kolonoskopiji. Retrospektivna analiza svih dijagnostičkih i kontrolnih kolonoskopija. MATERIJAL I METODE: Ponavljana je kolonoskopija kod ispitanika koj su na dijagnostičkim kolonoskopijama rađenim na Institutu za onkologiju Vojvodine u periodu 2005-2011. imali uredan kolonoskopski nalaz. Od 160 pozvanih ispitanika na ponovnu kolonoskopiju se odazvalo 64 ispitanika a 151 ispitanik je popunio upitnik o životnim navikama. Urađena je i retospektivna analiza 2750 dijagnostičkih kolonoskopija. Analizirani su rezultati 1064 prvih postoperativnih kolonoskopija kao i nalazi sa 1147 ponovljenih kolonoskopija kod ispitanika operisanih od kolorektalnog carcinoma koji su imali uredan nalaz na prvoj kolonoskopiji. REZULTATI: Od 160 pozvanih ispitanika,njih 64 (42,3%) se odazvalo na ponovni pregled (45 žena i 19 mu&scaron;karaca) prosečne starosti60,13 godina. Kod 15 ispitanika(24.3%) nađeno je ukupno 22 polipa (10 žena i 5 mu&scaron;karaca) bez statistički značajne razlike u pozitivnosti nalaza u odnosu na pol (x2test; x2=0,014; p=0,904) i pozitivnu porodičnu anamnezu (x2test; x2=0,125; p=0,724). 12 slucajeva (14,06%) su bili polipi visokog rizika: 5 (41.6%) lokalizovano u proksimalnom kolonu i 7 (58.3% ) u distalnom kolonu. Nije dijagnostikovan nijedan intervalni karcinom. Nije dokazana statistički značajna razlika u pozitivnosti nalaza na ponovljenoj kolonoskopiji u odnosu na razmak posmatran u grupama do 3 i do 5 godina od predhodne kolonoskpije (x2test; x2=0,020; p=0,887) niti ukoliko se posmatra po grupama do 5 i preko 5 godina od negative kolonoskopije (x2test; x2=3,082; p=0,079). Nema statistički značajne razlike u pozitivnosti nalaza na ponovljenoj kolonoskopiji u odnosu na to da li su pacijenti konzumiraju alkohol ili ne (x2test; x2=0,113; p=0,911) kao i u odnosu na to da li su pacijenti imali redovnu fizičku aktivnost (x2test; x2=0,476; p=0,490). Na dijagnostičkim kolonoskopijama je uočena statistički značajna razlika u uzrastu pacijenata u zavisnosti od razloga kolonoskopije (F=7,111; p=0,000) kod pacijenata kod kojih su dijagnostikovani polipi. Oni sa pozitivnom porodičnom anamnezom i polipima su statistički značajno mlađi u odnosu na ostale osim onih koji su se na pregled javili zbog bola u trbuhu poremećaja ritma stolice. Nije bilo statistički značajne razlike po polu, uzrastu, u razlogu kolonoskopije kod osoba sa dijagnostikovanim polipima. Statistički je značajniji broj žena sa lokalizacijom polipa u distalnom delu debelog creva u odnosu na proksimalni (x2test; x2=18,495; p=0,000). Kod mlađih uzrasnih grupa statistički značajnije su zastupljeni polipi u rektumu(x2test; x2=79,963; p=0,000). Ispitanici sa proksimalnom lokalizacijom polipa imaju 1,724 puta veću &scaron;ansu za adenome visokog rizika u odnosu na one sa distalnom lokalizacijom. Nema statistički značajne razlike u distribuciji karcinoma u odnosuna pol (x2test; x2=3,2110; p=0,201). Na 1064 prvih postoperativnih kolonoskopija je bilo ukupno 346 (32,5%) pozitivnih nalaza. Dijagnostikovano je 60 karcinoma od kojih je 43,3 % lokalizovano na anastomozi a kod 286 ispitanika nađeno je ukupno 546 polipa. Mu&scaron;karci statistički značajnije če&scaron;će imaju pozitiva nalaz (x2 test; x2=17,252; p=0,000). Bonferroni post hoc testom je utvrđeno da su polipi proksimalne lokalizacije statistički značajno veći od onih u rektumu (p=0,043). Na kontrolnim kolonoskopijama rađenim u cilju praćenja nakon resekcije kolorektalnog karcinoma multivarijatnom analizom ( pol, uzrast i vreme od operacije) utvrđeno je da mu&scaron;karci imaju 1,4 puta veću &scaron;ansu (OR=1,457) od žena za pojavu promena (polipa i karcinoma).Ispitanici kod kojih je od operacije pro&scaron;lo od 3 do 5 godina imaju 1,6 puta veću &scaron;ansu za pojavu promene u odnosu na one kod kojih je pro&scaron;la 1 godina (OR=1,605). ZAKLJUČAK: Kod 24.3% pregledanih ispitanika dijagnostikovani su polipi(jedan hipeplastičnii 21 adenoma ). 14,06% svih polipa je imalo karakteristike polipa visokog rizika bez statistički značajne razlike u pojavi polipa kod ispitanika kod kojih je pregled rađen 3,5 ili nakon 5 godina od prve negativne kolonoskopije. Nije dijagnostikovan niti jedan karcinom &scaron;to znači da nema potrebe za ponavljanjem kolonoskopija u kraćem vremenskom intervalu od unapred planirane kolonoskopije kod ispitanika koji su imali uredan inicijalni kolonoskopski nalaz &scaron;to se odnosi i na ponavljane kolonoskopije kod ispitanika operisanih od CRC-a. Na dijagnostičkim kolonoskopijama statistički značajniji broj žena sa lokalizacijom polipa u distalnom delu debelog creva u odnosu na proksimalni i nije zapažena razlika u distribuciji karcinoma u odnosu na pol i uzrast ispitanika.</p> / <p>INTRODUCTION:Colorectal cancer is the third most frequent illness of all carcinomas with an increase in the incidence of CRC in highly developed countries. 70% of patients with CRC are older than 65 years with higher incidence of proximal cancers compared to distal in all age groups and in both sexes. It is believed that 66-75% of CRC could be avoided through healthy lifestyle. 75% of CRC arise from adenomatous polyp cancer via sequences, and that more than 90% of adenoma will not progress to carcinoma. In studies of screening colonoscopy was reported 6-12% of unobserved large polyps and approximately 5% of the CRC on the initial colonoscopy.Postoperative periodic colonoscopy after colorectal cancer surgery aim to detect metachronous cancer and polyps and disease occurrence anastomoses but not proven survival benefit in subjects who had more frequent postoperative colonoscopy (per year) compared to those who were followed for 3 or 5 years. AIM:Prospective study of interval colon lesions occurrence (malignant and pre-malignant) in the period from 2-7 years after initial negative colonoscopy regardless of the reason for the check. Test of differences in lifestyle between subjects depending on the findings of the repeated colonoscopy.A retrospective analysis of all the diagnostic and control colonoscopy. METHODOLOGY: Repeated colonoscopy in subjects who are at-made diagnostic colonoscopy at the Oncology Institute of Vojvodina in the period 2005-2011 had normal colonoscopy findings. Of the 160 subjects invited to re colonoscopy for review responded 64 subjects and 151 subjects filled out a questionnaire about life habits. Retrospective analysis of 2750 and diagnostic colonoscopy has been done. Results of the 1064 first postoperative colonoscopy and results of the 1147 repeated colonoscopy in patients operated on for colorectal cancer that had normal findings on the first colonoscopy has been analyzed. RESULTS:Of the 160 invited subjects, 64 of them (42.3%) responded to the repeated review (45 women and 19 men), mean age 60.13 years. In 15 subjects (24.3%) found a total of 22 polyps (10 women and 5 men) with no statistically significant differences in positivity findings in relation to sex (x2test; x2 = 0.014; p = 0.904) and a positive family anamnesis (x2test; x2 = 0.125; p = 0.724).12 cases (14.06%) were high risk of polyps: 5 (41.6%) localized in the proximal colon, and 7 (58.3%) in the distal colon. Not a single interval cancer diagnosed. There was no statistically significant difference in positivity findings with repeated colonoscopy in relation to the distance observed in groups of 3 to 5 years from the previous colonoscopy (x2test; x2 = 0.020; p = 0.887) or when observed in groups up to 5 and over 5 years of negative colonoscopy (x2test; x2 = 3.082; p = 0.079). No statistically significant differences in positivity findings with repeated colonoscopy in relation to whether the patients consume alcohol or not (x2test; x2 = 0.113; p = 0.911) as well as in relation to whether patients are regularly exercising (x2test; x 2 = 0.476; p = 0.490). Statistically significant difference is confirmed in the age of patients at the diagnostic colonoscopy, depending on the reason for colonoscopy (F = 7.111; p = 0.000) in patients who were diagnosed polyps. Those with a family anamnesis and polyps were statistically significant younger in comparison to others except those who have come forward for review because of abdominal pain and bowel movement rhythm disturbances.There were no statistically significant differences by sex, age, the reason for colonoscopy in patients diagnosed with polyps.Statistically is more significant number of women with the localization of polyps in the distal part of the colon comparing to the proximal (x2test; x2 = 18,495; p = 0.000).In younger age groups are represented statistically significant polyps in the rectum (x2test; x2 = 79.963, p = 0.000). Subjects with proximal localization of polyps are 1,724 times more likely for high-risk adenomas compared to those with distal localization.No statistically significant differences in the distribution of cancer in relation to sex (x2test; x2 = 3.2110; p = 0.201).On the first postoperative colonoscopy in 1064 subjects there were a total 346 (32.5%) positive findings. 60 carcinoma diagnosed of which 43.3% is localized on the anastomosis and in 286 of the subjects had a total of 546 of the polyps.Men statistically significantly more likely to have positive findings (x2 test; x2 = 17,252; p = 0.000). Bonferroni post hoc test showed that polyps proximal localization significantly bigger than those in the rectum (p = 0.043). On the control colonoscopy-made for the purpose of monitoring after resection of colorectal cancer by multivariate analysis (sex, age and time of surgery) it has been found that men are 1.4 times more likely (OR = 1.457) than women for the occurrence of changes (polyps and cancers).Subjects having passed since the operation of 3 to 5 years are 1.6 times more likely to develop a change with respect to those in which the more than one year elapsed (OR = 1.605). CONCLUSION:In 24.3% subjects were diagnosed polyps (one hyperplastic and 21 adenomas).14.06% of all polyps had the characteristics of high-risk polyps with no statistically significant difference in the occurrence of polyps in subjects where the examination was done after 3,5 or 5 years since the first negative colonoscopy. No cancers diagnosed, meaning there is no need to repeat colonoscopy in a shorter period of time than pre-planned colonoscopy in subjects who had normal initial colonoscopy findings which refers to the repeated colonoscopies in subjects operated on for CRC.For diagnostic colonoscopy statistically significant number of women with the localization of polyps in the distal part of the colon compared to proximal and was not observed differences in the distribution of carcinoma in relation to sex and age of the subject.</p>

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