Three-dimensional volume data is routinely produced, at increasingly high spatial resolution, in computer simulations and image acquisition tasks. In-situ visualization, the visualization of an experiment or simulation while it is running, enables new modes of interaction, including simulation steering and experiment control. These can provide the scientist a deeper understanding of the underlying phenomena, but require interactive visualization with smooth viewpoint changes and zooming to convey depth perception and spatial understanding. As the size of the volume data increases, however, it is increasingly challenging to achieve interactive visualization with smooth viewpoint changes. This thesis presents an end-to-end solution for interactive in-situ visualization based on novel extensions proposed to the Volumetric Depth Image (VDI) representation. VDIs are view-dependent, compact representations of volume data than can be rendered faster than the original data. Novel methods are proposed in this thesis for generating VDIs on large data and for rendering them faster. Together, they enable interactive in situ visualization with smooth viewpoint changes and zooming for large volume data. The generation of VDIs involves decomposing the volume rendering integral along rays into segments that store composited color and opacity, forming a representation much smaller than the volume data. This thesis introduces a technique to automatically determine the sensitivity parameter that governs the decomposition of rays, eliminating the need for manual parameter tuning in the generation of a VDI. Further, a method is proposed for sort-last parallel generation and compositing of VDIs on distributed computers, enabling their in situ generation with distributed numerical simulations. A low latency architecture is proposed for the sharing of data and hardware resources with a running simulation. The resulting VDI can be streamed for interactive visualization. A novel raycasting method is proposed for rendering VDIs. Properties of perspective projection are exploited to simplify the intersection of rays with the view-dependent segments contained within the VDI. Spatial smoothness in volume data is leveraged to minimize memory accesses. Benchmarks are performed showing that the method significantly outperforms existing methods for rendering the VDI, and achieves responsive frame rates for High Definition (HD) display resolutions near the viewpoint of generation. Further, a method is proposed to subsample the VDI for preview rendering, maintaining high frame rates even for large viewpoint deviations. The quality and performance of the approach are analyzed on multiple datasets, and the contributions are provided as extensions of established open-source tools. The thesis concludes with a discussion on the strengths, limitations, and future directions for the proposed approach.

Los vasos sanguíneos poseen características estructurales y funcionales que disminuyen o amortiguan la pulsatilidad del flujo y la presión generada por la eyección ventricular. Este amortiguamiento determina que el flujo capilar sea continuo para optimizar la perfusión tisular y que la pulsatilidad de la onda de presión sea suficientemente baja como para no dañar la fina pared capilar. Es sabido que la rigidez arterial es determinada tanto por componentes funcionales como estructurales relacionados con las características elásticas propias de las arterias. Es sabido que la presión arterial (BP) persistentemente elevada modifica la rigidez arterial incrementándola debido a modificaciones en la estructura de las fibras de colágeno y elastina. Por otro lado, el incremento de la rigidez arterial, incrementa la velocidad de onda de pulso arterial (PWV) generada por la eyección ventricular. De modo similar, el incremento de la rigidez arterial provoca un aumento en la velocidad de la onda reflejada de presión, la cual se produce en las paredes de las arterias y las bifurcaciones del árbol arterial, esta condición modifica la morfología del pulso digital de volumen (DVP). Se estudió en esta investigación el comportamiento de la velocidad de onda de pulso en diferentes sitios de interés con respecto a la presión arterial y factores de riesgo cardiovascular que intervienen. Las valoraciones se realizaron a la velocidad de onda de pulso brazo-tobillo (baPWV), velocidad de onda de pulso dedo índice-dedo mayor (ftPWV) así como a las medidas de velocidad de onda de pulso corazón-dedo índice (hfPWV) y velocidad de onda de pulso corazón-dedo mayor (htPWV). Estudios similares se realizaron con el pulso digital de volumen (DVP) en su comportamiento con la presión arterial y factores de riesgo. Los parámetros de interés que se evaluaron son el índice de rigidez (SIDVP) y el índice de reflexión (RIDVP). / Padilla Hernández, JM. (2010). Caracterización de la onda de pulso arterial, velocidad (PWV) y morfología (DVP), como estimadores de la presión arterial [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/7767

<p>Uvod: Pacijenti na hemodijalizi (HD) imaju visoku stopu ukupnog i kardiovaskularnog morbiditeta i mortaliteta. Preko 80% bolesnika na HD ima neki tip kardiovaskularne bolesti. Hipervolemija značajno doprinosi njihovom nastanku, dovodeći do hipertenzije, hipertrofije miokarda leve komore, srčane insuficijencije i nastanka plućnog edema. Procena stanja volemije kod pacijenata na HD najče&scaron;će se vr&scaron;i kliničkim pregledom, uprkos nezadovoljavajućoj specifičnosti i senzitivnosti. Hipervolemija je prisutna kod određenog broja pacijenata, uprkos normotenziji, odsustvu edema i urednom auskultatornom nalazu na plućima. Različite metode se koriste za procenu stanja volemije, svaka sa određenim manama. Upotreba analize bioelektrične impedanse zahteva skupu opremu i potro&scaron;ni materijal, vrednosti B-tipa natriuretskog peptida (BNP) i njegovog N terminalnog propeptida (NT-proBNP) zavise i od stanja volemije i od srčane funkcije, kao i od tipa dijalizne membrane. Ehokardiografija (EHO) i ultrazvuk donje &scaron;uplje vene (UZ ICV) sa određivanjem dijametara u inspirijumu i ekspirijumu (IVCDi i IVCDe) zahteva posebno obučen kadar. Ultrazvuk pluća (UZ pluća) je jednostavna, brza i jeftina metoda za detekciju ekstravaskularne plućne tečnosti (EVLW). EVLW predstavlja onu količinu tečnosti koja se nalazi u plućnom intersticijumu. UZ pluća detektuje EVLW kao UZ artefakte zvane &bdquo;B linije&ldquo;. Količina EVLW zavisna je od pritiska punjenja leve komore i povećava se u stanjima hipervolemije, &scaron;to se na UZ pluća manifestuje kao veći broj detektovanih &bdquo;B linija&ldquo;. Zbir svih &bdquo;B linija&ldquo; detektovanih na definisanim mestima na grudnom ko&scaron;u naziva se &bdquo;skor B linija&ldquo; (BLS) i koristi se za kvantifikaciju EVLW pomoću UZ pluća. Cilj: Uporediti adekvatnost i efikasnost UZ pluća u proceni stanja volemije kod pacijenata na HD u odnosu na standardne tehnike UZ donje &scaron;uplje vene, EHO i BNP-a. Proceniti mogućnost pojednostavljenja protokola UZ pregleda pluća redukcijom broja analiziranih plućnih polja. Materijal i metode: Istraživanje je sprovedeno kao studija preseka od aprila 2016. do juna 2017. godine na 83 pacijenta koji su se nalazili na hroničnom programu HD u Službi za HD Odeljenja za internu medicinu Op&scaron;te bolnice Kikinda. Ispitanicima je prvog dana HD u nedelji neposredno pre HD urađen UZ pluća, UZ IVC, EHO, i uzorkovanje krvi za određivnje vrednosti BNP-a. Potom su pacijenti dijalizirani prema svojim utvrđenim HD protokolima. Neposredno nakon HD ponovljeni su UZ pluća, UZ IVC, EHO, a uzorkovanje krvi za BNP je ponovljeno pre započinjanja sledeće HD u nedelji, da bi se izbegao neposredni postdijalizni skok BNP-a. Za poređenje varijabli kori&scaron;ćeni su T test parova odnosno Vilkoksonov test, a za ispitivanje korelacije Pirsonov odnosno Spirmanov test, u zavisnosti od distribucije varijabli. Razlike između grupa ispitanika ispitivane su pomoću jednofaktorske analize varijanse (ANOVA) za kontinuirane varijable, a za kategorijske je kori&scaron;ćena analiza kontingencijskih tabela. Analiza glavnih komponenata (PCA) je kori&scaron;ćena za procenu mogućnosti redukcije broja ispitivanih plućnih polja. Rezultati: Utvrđena je signifikantna razlika između predijaliznih (pre HD) srednjih vrednosti BLS-a (18,85) i postdijaliznih (post HD) srednjih vrednosti BLS-a (7,30); između srednjih vrednosti BNP-a pre HD (894,89 pg/ml) i post HD (487,74 pg/ml); između srednjih vrednosti IVCDe pre HD (10,45 mm) i post HD (7,85 mm); između srednjih vrednosti IVCDi pre HD (7,20 mm) i post HD (4,41 mm); između srednjih vrednosti indeksa kolapsibilnosti IVC pre HD (32%) i post HD (45%). Utvrđene su i signifikantne razlike između srednjih vrednosti sledećih EHO parametara: dijametar leve pretkomore pre HD (3,78 cm) i post HD (3,53 cm), dijametra leve komore u dijastoli pre HD (5,21 cm) i post HD (4,96 cm), dijametra leve komore u sistoli pre HD (3,69 cm) i post HD (3,43 cm) i zapremine leve pretkomore u sistoli pre HD (60,54 ml) i post HD (52,36 ml). Sve razlike su bile signifikantne na nivou p&lt;0,0001. Dokazana je signifikantna pozitivna korelacija između BLS-a pre HD i BNP-a pre HD (&rho;=0,49, p&lt;0,01) i BNP-a post HD (0,43, p&lt;0,01); BLS-a pre HD i IVCDe pre HD (&rho;=0,29, p&lt;0,01), IVCDi pre HD (&rho;=0,30, p&lt;0,05) i IVCDi post HD (&rho;=0,23, p&lt;0,05) kao i između BLS-a post HD i BNP-a pre HD (&rho;=0,44, p&lt;0,01) i BNP-a post HD (&rho;=0,42, p&lt;0,01), između BLS-a post HD i IVCDe pre HD (&rho;=0,29, p&lt;0,05) IVCDi pre HD (&rho;=0,33, p&lt;0,05) i IVCDi post HD (&rho;=0,23, p&lt;0,05). Utvrđeno je da su bolesnici sa vi&scaron;im BLS-om imali niže vrednosti hemoglobina (p=0,006) i vi&scaron;e vrednosti visoko senzitivnog troponina T (p=0,02), kao i veće dijametre leve komore u sistoli (p=0,04). Pomoću PCA utvrđeno je da je moguća redukcija broja ispitivanih plućnih polja na 4 do 12 plućnih polja, koja bi bila odgovorna za 75,38% odnosno 84,51% varijabilnosti BLS-a. Zaključak: UZ pluća može adekvatno i efikasno da proceni stanje volemije i može se koristiti za ovu svrhu kod pacijenata na hroničnom programu HD. UZ pluća je brz, jednostavan i jeftin pregled koji se može izvoditi u bolesničkoj postelji i koji daje pouzdan podatak o bolesnikovom statusu volemije u realnom vremenu. UZ pluća bez većih te&scaron;koća mogao uključiti u kliničke protokole u svim centrima sa dostupnom opremom. Postoji mogućnost redukcije broja ispitivanih plućnih polja i time pojednostavljenja samog UZ pregleda pluća. UZ pluća može koristiti u proceni srčane funkcije kod pacijenata na HD. Pacijenti koji su procenjeni kao hipervolemični pomoću UZ pluća imaju povećan kardiovaskularni rizik, kao i pacijenti procenjeni kao hipervolemični pomoću vrednosti BNP-a i dijametra D&Scaron;V.</p> / <p>Introduction: Patients on hemodialysis (HD) have a high general morbidity and all-cause mortality, as well as high cardiovascular morbidity and mortality. More than 80% of patients on HD have some cardiovascular disease. Hypervolemia plays a significant role here, contributing to hypertension, left ventricular hypertrophy, heart failure and pulmonary edema. Fluid status assessment in HD is still mostly clinical, despite having low specificity and sensitivity. A number of patients remain hypervolume, despite being normotensive, without edema or bibasilar crackles on lung auscultation. Different methods are used for volume status assessment in HD setting, no method without its flaws. Bioelectric impedance analysis requires expensive equipment and supplies. B type natriuretic peptide (BNP) values, and those of its terminal propeptide (NT-proBNP) depend on volume status, cardiac function as well as type of dialysis membrane used. Echocardiography (ECHO) and ultrasonography of inferior vena cava (IVC US) with measurements of its diameters in inspirum and expirium (IVCDi and IVCDe) require trained medical personnel. Lung ultrasound (LUS) is a simple, fast and inexpensive method for detection of extravascular lung water (EVLW), which is the water contained in the lung interstitium. LUS detects EVLW as ultrasonographic artefacts called &bdquo;B lines&ldquo;. EVLW is dependent on left ventricular filling pressures and is increased in volume overload, manifesting as more &bdquo;B lines&ldquo; on LUS. The sum of all &bdquo;B lines&ldquo; detected on predetermined places on the chest is called &bdquo;B line score&ldquo; (BLS) and is used to quantify EVLW using LUS. Goal: Compare the adequacy and efficacy of LUS in assessment of volume status in patients on HD to other methods (IVC US, ECHO, BNP). Assess the possibility of simplifying LUS by reducing the number of examined lung fields. Materials and methods: A cross-section study was performed from April 2016 to June 2017. on 83 dialysis patients in Dialysis unit of Internal medicine department of General hospital Kikinda. LUS, ECHO, IVC US and blood sampling for BNP were performed on the first dialysis day of the week, just prior to HD. Patients were then dialyzed according to their dialysis protocols. After HD all tests were repeated, except blood sampling for BNP, which was sampled just prior to the next HD session in order to avoid elevated BNP values after HD. Variables were compared using double sample T test or Wilcoxon test. Correlation was assessed using Pearson&rsquo;s or Spearman&rsquo;s test, depending on variable distribution. Differences between groups were tested using one-way analysis of variance for continuous variables and contingency tables for categorical variables. Principal component analysis (PCA) was used to assess the possibility of lung field reduction. Results: There was a significant difference between BLS predialysis (pre HD) (mean 18,85) and BLS postdialysis (post HD) (mean 7,30); between IVCDe pre HD (mean 10,45 mm) and IVCDe post HD (mean 7,85 mm); between IVCDi pre HD (mean 7,20 mm) and IVCDi post HD (mean 4,41 mm); between CCI pre HD (mean 32%) and CCI post HD (mean 45%), between BNP pre HD (mean 894,89 pg/ml) and BNP post HD (mean 487,74 pg/ml). There was also a significant difference between the following ECHO parameters: left atrial diameter pre HD (mean 3,78 cm) and post HD (mean 3,53 cm), left ventricular internal diameter in diastole pre HD (mean 5,21 cm) and post HD (mean 4,96 cm) and left ventricular internal diameter in sistole pre HD (mean 3,69 cm) and post HD (mean 3,43 cm), left atrial volume in sistole pre HD (mean 60,54 ml) and post HD (mean 52,36 ml). All differences were significant at a level of p&lt;0,0001. There was a significant positive correlation between BLS pre HD and BNP pre HD (&rho;=0,49, p&lt;0,01) and BNP post HD (&rho;=0,43, p&lt;0,01); BLS pre HD and IVCDe pre HD (&rho;=0,29, p&lt;0,01) IVCDi pre HD (&rho;=0,30, p&lt;0,05) and IVCDi post HD (&rho;=0,23, p&lt;0,05); between BLS post HD and BNP pre HD (&rho;=0,44, p&lt;0,01) and BNP post HD (&rho;=0,42, p&lt;0,01); between BLS post HD and IVCDe pre HD (&rho;=0,29, p&lt;0,05), IVCDi pre HD (&rho;=0,33, p&lt;0,05) and IVCDi post HD (&rho;=0,23, p&lt;0,05). Subjects with higher BLS had lower hemoglobin levels (p=0,006), higher troponin T levels (p=0,02) and greater left ventricular internal dimensions in sistole (p=0,04). PCA showed that there is a possibility of lung field reduction to 12 lung fields and even down to 4 lung fields, which would account for 84,51% or 75,38% of BLS variability. Conclusion: LUS can be used to adequately and effectively assess volume status in patients on HD. LUS is simple, fast and inexpensive exam with bedside capability, which gives accurate volume status data in real time. The exam can be implemented into dialysis unit protocols without difficulty. There is a possibility of simplifying LUS by reducing the number of examined lung fields. LUS can be used in assessment of cardiac function in patients on HD. Patients rated as hypervolemic by LUS have increased cardiovascular risk, as well as patients rated as hypervolemic by BNP levels or IVC diameters.</p>

In dieser Studie sind die Massenvolumina und die Innenvolumina rechter und linker Ventrikel von 36 Patienten (15 Frauen und 21 Männer, im Alter zwischen 24 und 82 Jahren, mittleres Alter 54 Jahre) mittels transösophagealer Echokardiographie (TEE, HP SONOS 1500 mit einen rotierenden 5Mhz Schallkopf) und Magnetresonanztomographie (MRT, 1,5T Ganzkörper-MRT - ACS, Philips. T1-gewichtete Turbo-Gradientenecho-Sequenz) untersucht worden. Ziel ist es beide Untersuchungsmethoden auf Übereinstimmungen und Unterschiede bei Messung von Massenvolumina und Innenvolumina beider Ventrikel unter Berücksichtigung von Sinusrhythmus (26 Ventrikel) und Vorhofflimmern (18 Ventrikel) zu überprüfen. Dabei werden sowohl die Innenvolumina, die freien Wände und die Septen jeweils in der Enddiastole und in der Endsystole verglichen als auch die abgeleiteten Parameter, Ejektionsfraktionen und Schlagvolumina. Beide Methoden werden mit der Scheibchen-Summationsmethode aus jeweils vier Einzelmessungen verglichen. Die graphische und statistische Auswertung erfolgt mittels Bland-Altmann-Plot. Im T-Test für unverbundene Stichproben stellt sich kein signifikanter Unterschied zwischen linken und rechten sowie zwischen großen und kleinen Ventrikeln heraus. Es besteht ein signifikanter Unterschied zwischen Ventrikeln mit Vorhofflimmern und Sinusrhythmus, so dass wir hier einen Vergleich aufstellen. Die enddiastolischen Messungen der Innenvolumina und freien Wände zeigen deutliche Diskrepanzen der Ventrikel mit Sinusrhythmus und Vorhofflimmern - um etwa das Doppelte der Standardabweichung und des systematischen Fehlers. Die enddiastolischen Septen sind annährend gleich gut dargestellt. In der Endsystole liefern die Messungen der Innenvolumina, der freien Wände und der Septen annähernd gleiche Ergebnisse wie in der Enddiastole. Die errechneten Ejektionsfraktionen haben sowohl bei Sinusrhythmus als auch bei Vorhofflimmern gleich gut Standardabweichungen und systematische Fehler. Ähnlich verhält es sich bei den Daten der Schlagvolumina. Absolut betrachtet liefern beide volumetrischen Messmethoden bei Ventrikeln mit Sinusrhythmus und Vorhofflimmern akzeptable Ergebnisse, da die Differenzen nur wenige Milliliter betragen. / This study compares the feasibility of calculating the masses and the inner volumes the of right and left heart ventricles in 36 patients (15 female and 21 male, ages between 24 and 82 years, mean 54 years) with transesophageal echocardiography (TEE, HP SONOS 1500 with a rotating 5Mhz transducer) and cardiac MRI (1,5Tesla whole body MRI, ACS Philips with a Synergy Cardiac Coil, T1-Turbo Gradient Echo). We want to compare both methods in calculating the inner volumes, the septal and the free myocardial masses in endsystolic and enddiastolic phases as well as the ejection fraction (EF) and the stroke volume (SV) in ventricles with sinusrhythm (n=26) and with atrial fibrillation (n=18). Both methods are evaluated by a disc-summation method from a mean value of four different measurement. The statistic analysis is done with a Bland-Altmann-Plot. The T-test shows no significant difference between big and small or right and left ventricular masses, but it shows a significant difference in the measured data of ventricles with sinusrhythm and those with atrail fibrillation. A subgroup analysis is performed on the latter. The standard error of mean and the systemic mistake of the inner- and myocardial-volumes differ about double the size with ventricles in atrial fibrillation from those with sinusrhythm. The septal volumes show no differences in both subgroups. The endsystolic measurements are about equal from those in the enddiastolic phase. The EF and the SV have equal standard error of means and systemic mistakes in both subgroups of sinusrhythm and atrial fibrillation. In conclusion both methods are equally reliable in the volumetric measurement of ventricles with sinusrhythm and atrial fibrillation, because the absolute value differs just a few milliliters.

<p>Prema literaturnim podacima poslednjih godina velika pažnja je usmerena ka operativnom riziku i mortalitetu koji su postali najvažniji kriterijumi u ocenama rezultata rada hirur&scaron;kih ustanova, ali i svakog hirurga posebno. Zahvaljujući kompleksnom profilu pacijenata koji se podvrgavaju hirur&scaron;kim intervencijama, precizna procena operativnog rizika postaje sve teža. Predikcija ishoda intervencije u najvećoj meri zavisi od preoperativnih faktora rizika. Ipak, neminovno je da i faktori koji su vezani za samu operaciju u određenom stepenu utiču na ishod hirur&scaron;ke intervencije. Shodno tome, dobar model za procenu rizika treba da obuhvati faktore koji će imati najbolju prediktivnu vrednost. Thoracoscore je prvi bodovni sistem razvijen od strane Francuskog udruženja grudnih i vaskularinih hiruga. Zbog nedovoljne primene tokom poslednje decenije i nekonzistentnih rezultata nije do&scaron;lo do &scaron;irokog međunarodnog prihvatanja ovog modela i njegove rutinske upotrebe. Ova činjenica ukazuje na nedostake samog modela i potrebu za rekalibracijom u cilju postizanja bolje saglasnosti između predikcije operativnog rizika i kliničkog stanja bolesnika. Cilj rada je bio da se ustanovi realna vrednost Thoracoscore bodovnog sistema u proceni operativnog rizika i mortaliteta nakon anatomskih i neanatomskih resekcija pluća u na&scaron;im uslovima, i da se utvrdi prediktivna vrednost faktora rizika koji nisu obuhvaćeni Thoracoscore bodovnim sistemom na ishod grudno-hirur&scaron;kih operacija. Istraživanje je sprovedeno po tipu prospektivne kliničke studije i obuhvatilo je 957 bolesnika operisanih na Klinici za grudnu hirurgiju Instituta za plućne bolesti Vojvodine. Izvr&scaron;ene hirur&scaron;ke procedure bile su anatomske resekcije (lobektomija, bilobektomija, pneumonektomija, Sleeve resekcija, segmentektomija) i neanatomske resekcije pluća (Wedge resekcija i druge atipične resekcije). Thoracoscore je izračunat za svakog bolesnika na osnovu devet parametara: godine starosti, pol, ASA skor, dispnea skor, procena op&scaron;teg stanja bolesnika, dijagnostička grupa, hitnost operacije, vrsta operacije i broj komorbiditeta. S obzirom da prediktivna vrednost Thoracoscore bodovnog sistema u proceni operativnog rizika nije bila adekvatna realnom stanju, regresionom analizom je evaluiran značaj tri nova faktora: forsirani ekspiratorni volumen u prvoj sekundi (FEV1), reoperacija i hirur&scaron;ki pristup (torakotomija, video-asistirana torakoskopija &ndash; VATS). Nakon &scaron;to je univarijantnom analizom potvrđeno da su ovi faktori nezavisni prediktori operativnog ishoda, originalni Thoracoscore model je rekalibrisan. Multivarijantnom analizom putem logističke regresije izračunati su novi beta koeficijenti za originalnih devet faktora, kao i za tri nova, te je kreiran lokalni model za procenu operativnog rizika koji je prilagođen na&scaron;oj populaciji. Prosečna starosti bolesnika bila je 62 &plusmn; 7,52 godina. Većinu uzorka (60,7%) činili su pripadnici mu&scaron;kog pola. Najveći broj resekcija činile su lobektomije (61,4%). Malignitet je bio najučestalija indikacija za operaciju (90,3%). Najveći broj bolesnika imao je 1-2 komorbiditeta (64,3%). Prosečna stopa operativnog rizika na osnovu Thoracoscore-a (4,7% ) bila je veća je od stvarnog (2,9%) intrahospitalnog mortalita (p&lt;0,01). Ovaj model je pokazao zadovoljavajuće rezultate jedino u grupi niskog rizika. Predikcija mortaliteta lokalnim modelom za procenu operativnog rizika u grudnoj hirurgiji se, u statističkom smislu, ne razlikuje od stvarnog mortaliteta (p = NS). Thoracoscore ima dobru diskriminativnu moć, ali nezadovoljavajuću kalibrisanost. Shodno tome, Thoracoscore model se može koristiti za stratifikaciju rizika, ali ne i za predikciju mortaliteta. Za razliku, lokalni model je pokazao dobru diskriminaciju i kalibrisanost u na&scaron;im uslovima. Interni model za procenu rizika bi bio od velike koristi u svakodnevnom kliničkom radu, budući da bi oslikavao realno stanje populacije u kojoj je razvijen i vr&scaron;io preciznu predikciju operativnog rizika.</p> / <p>According to the literature data, over the past several years, great attention has been focused on operative risk and mortality which have become the most important criteria in evaluating the results from surgical departments and individual surgeons, as well. Because of complex profiles of patients undergoing surgical interventions, it is becoming more difficult to assess the risk precisely. Prediction of surgical outcomes mostly depends on the preoperative risk factors. However, factors related to the procedure itself effect the surgical outcome to a certain degree. Therefore, a good risk assessment model must contain factors which will have the best predictive value. Thoracoscore is the first scoring system developed by the French Association of Thoracic and Vascular Surgeons. Due to insufficient utilization over the past decade and inconsistent results, this model has not been widely accepted for routine use. This fact indicates that the model lacks certain aspects and needs to be recalibrated in order to achieve better concordance between the predicted operative risk and the clinical state of the patient. The aim of this study was to determine real value of Thoracoscore scoring system for estimation of operative risk and mortality following anatomic and non-anatomic lung resections in our settings, and to determine predictive value of factors not included in Thoracoscore on the outcome of thoracic surgeries. This prospective study included 957 patients who underwent lung resections at the Thoracic surgery clinic of Institute for Lung Diseases of Vojvodina. Performed surgical procedures were anatomic lung resections (lobectomy, bilobectomy, pneumonectomy, Sleeve resection, segmentectomy) and non-anatomic lung resections (Wedge resection and other atypical resections). Thoracoscore was calculated for each patient based on the following nine parameters: age, gender, ASA score, dyspnea score, performance status classification, diagnostic group, urgency of surgery, surgical procedure and number of comorbidities. Because predictive value of Thoracoscore did not correspond to the actual results, regression analysis was used to evaluate the significance of three new risk factors: forced expiratory volume in the first second (FEV1), reoperation, and surgical approach (thoracotomy, video-assisted thoracoscopy &ndash; VATS). After univariate analysis confirmed that these three factors are independent predictors of operative risk, the original Thoracoscore model was recalibrated. With the use of multivariate analysis by logistic regression, new beta coefficients were calculated for the original nine parameters, as well as for the new three, and consequently a local model for surgical risk assessment that is adapted to our population was created. Average age of patients was 62 &plusmn; 7.52 years. Most of the patients were males (60.7%). Lobectomies constituted the largest number (61.4%) of performed surgeries. The most common indications for surgery were malignant causes (90.3%). Most frequently, patients had 1-2 comorbidities (64.3%). Mean operative risk based on Thoracoscore (4.7%) was greater than the actual intrahospital mortality (2.9%) (p&lt;0.01). This model had adequate results only in the low risk group of patients. Predicted mortality by the local model was not statistically different from the actual mortality (p = NS). Thoracoscore had good discriminative ability, but inadequate calibration. Because of this, Thoracoscore model can be used for risk stratification, but not for mortality prediction. On the other hand, local model showed good discrimination and calibration in our population. Therefore, an internal model for risk assessment would be of great use in everyday clinical practice because it would reflect the real state of the population in which it was developed, predicting the risk more precisely.</p>

In this work a p-i-n type heterojunction architecture for organic solar cells is shown, where the active region is sandwiched between two doped wide-gap layers. The term p-i-n means here a layer sequence in the form p-doped layer, intrinsic layer and n-doped layer. The doping is realized by controlled coevaporation using organic dopants and leads to conductivities of 10-4 to 10-5 S/cm in the p- and n-doped wide gap layers, respectively. The conductivity and field effect mobility of single doped layers can be described quantitatively in a self-consistent way by a percolation model. For the solar cells the photoactive layer is formed by a mixture of phthalocyanine zinc (ZnPc) and the fullerene C60 and shows mainly amorphous morphology. The solar cells exhibit a maximum external quantum efficiency of 40% between 630nm and 700nm wavelength. With the help of an optical multilayer model, the optical properties of the solar cells are optimized by placing the active region at the maximum of the optical field distribution. The results of the model are largely confirmed by the experimental findings. The optically optimized device shows an internal quantum efficiency of around 85% at short-circuit conditions and a power-conversion efficiency of 1.7%.

Process-induced Long-term Deformation Behavior of Injection Molded Semicrystalline Thermoplastics Injection molding is a very complex process because the polymer experiences a complex thermorheological history during molding that influences the molecular orientation, residual stresses, frozen-in free volume and crystallinity inside the part. These generally govern the final part properties. Therefore it is highly desirable to anticipate the effect of process parameters on the resulting microstructure and mechanical properties of the finished part in the long run. In the case of a semicrystalline thermoplastic part, the problem in understanding the deformation behavior arises from its two-phase structure and a tendency exists to concentrate primarily on the effect of the crystalline phase on the deformation behavior, while the contribution of the amorphous phase is less investigated. In this work, the influence of the processing parameters on the deformation behavior of injection molded semicrystalline thermoplastic parts, viz., syndiotactic Polystyrene (sPS) and Polybutylene terepthalate (PBT), has been monitored through creep. The resulting internal structures due to processing have been determined and the deformation behavior has been analyzed. It has been observed that only the rate of cooling shows a remarkable effect on the long-term viscoelastic behavior of an injection molded semicrystalline thermoplastic part as it influences not only the crystalline, but also the free volume fraction, whereas the different states of frozen-in orientations and pressure-induced densification have only a negligible effect. Besides, physical aging also plays an important role in the deformation behavior of the injection moldings which was manifested with the decrease in the tendency to creep. Therefore, it was suggested that the cooling rate during injection molding and the aging time can significantly affect the long-term deformation behavior of the injection molded semicrystalline thermoplastics. The results also showed that when no significant effect is observed in terms of short-term mechanical properties by changing the processing conditions, but while considering the long-term behavior they show a significant effect.

No description available.

Wir schlagen einen allgemein anwendbaren Algorithmus vor, der unter Verwendung des Skalarprodukts von Kraft und Weg zum richtigen Vorzeichen in den Gleichungen für die Arbeit und die Potentielle Energie bei reversiblen Prozessen (Druck-Volumen-Änderung, Dehnung, Elektrostatische Wechselwirkung, Hub)führt. Wir zeigen, dass es dabei möglich ist, systemimmanente oder externe Kräfte zu benutzen. Wir zeigen, dass bei Verwendung von systemimmanenten Kräften das Skalarprodukt mit negativem Vorzeichen anzusetzen ist. Zudem ist es sehr wichtig, nötige Vorzeichenwechsel bei den einzelnen Schritten zu beachten. Wir betonen dies, weil gelegentlich übersehen wird, dass ein Vorzeichenwechsel nötig ist, wenn das Wegdifferential ds durch das Höhendifferential dh beziehungsweise durch das Abstandsdifferential dx oder dr ersetzt werden muss.

Introdução: O Débito Cardíaco Diminuído e o Volume Excessivo de Líquidos são os principais diagnósticos de Enfermagem (DE) presentes em pacientes admitidos com insuficiência cardíaca (IC) descompensada. A avaliação e determinação das características definidoras (CD) destes diagnósticos são fundamentais para orientar as intervenções de enfermagem adequadas e preconizadas para estes pacientes. A validação clínica das CD destes diagnósticos permanecem inexploradas no contexto da IC descompensada. Objetivo: Validar clinicamente as CD dos DE Débito Cardíaco Diminuído e Volume Excessivo de Líquidos em pacientes com IC descompensada. Métodos: Estudo transversal contemporâneo realizado de janeiro a junho de 2007 em hospital universitário em Porto Alegre, Rio Grande do Sul. Para a validação clínica utilizou-se- um instrumento contendo as CD dos diagnósticos em estudo, aplicado por duas enfermeiras peritas em cardiologia. Incluiu-se pacientes com fração de ejeção do ventrículo esquerdo  45% e que obtiveram oito ou mais pontos, conforme os critérios de Boston para classificação de IC descompensada. Para a validação do diagnóstico Volume Excessivo de Líquidos incluiu-se pacientes com disfunção sistólica ou diastólica Resultados da validação do DE Débito Cardíaco Diminuído: Incluiu-se 29 pacientes com idade média de 61 + 14 anos; 15 (51%) sexo masculino; fração de ejeção média de 28% + 9; De acordo com a taxa de fidedignidade (R) entre as peritas, as CD consideradas maiores (R ≥ 0,80) para a validação do diagnóstico foram a fadiga (R=1), a fração de ejeção do ventrículo esquerdo diminuída (R=1), a dispnéia (R=0,96), o edema (R= 0,95), a ortopnéia (R= 0,95), a dispnéia paroxística noturna (R=0,88) e a pressão venosa central elevada (R=0,85). As características consideradas como menores ou secundárias foram o ganho de peso (R=0,78), a distenção da veia jugular (R=0,74), as palpitações (R=0,71), a oligúria (R=0,67), a tosse (R=0,63), a pele fria e pegajosa (R=0,61) e as mudanças na cor da pele (R=0,52). Resultados da validação do DE Volume Excessivo de Líquidos: Incluiu-se 32 pacientes com idade média de 60,5 + 14,3 anos; 17 (53%) sexo masculino; fração de ejeção média de 31% + 11,5. Seguindo a taxa de fidedignidade (R) entre as peritas, as CD consideradas maiores (R ≥ 0,80) para a validação do diagnóstico Volume Excessivo de Líquidos foram a dispnéia (R=0,97), a ortopnéia (R=0,95), o edema (R= 0,91), o refluxo hepatojugular positivo (R=0,90), a dispnéia paroxística noturna (R=0,88), a congestão pulmonar (R=0,87) e a pressão venosa central elevada (R=0,85). As características consideradas como menores ou secundárias foram o ganho de peso (R=0,79), a hepatomegalia (R=0,78), a distenção da veia jugular (R=0,76), as crepitações (R=0,66), a oligúria (R=0,63) e o hematócrito e a hemoglobina diminuídos (R=0,51). Conclusão: Demonstrou-se neste estudo que as características definidoras com R entre 0,50 e 1 foram validadas para os diagnósticos Débito Cardíaco Diminuído e Volume Excessivo de Líquidos em pacientes com IC descompensada. / Introduction: Decreased Cardiac Output and Fluid Volume Excess are the major nursing diagnoses (ND) among patients with decompensated heart failure (DHF). The assessment and determination of the defining characteristics (DC) of those diagnoses are crucial for selecting the appropriate nursing interventions indicated for these patients. The clinical validation of the DC of those diagnoses has not been investigated in the context of DHF. Purpose: To clinically validate the DC of Decreased Cardiac Output and Fluid Volume Excess ND in patients with DHF. Methods: Cross-sectional study conducted from January to June 2007 at a teaching hospital in Porto Alegre, state of Rio Grande do Sul, Brazil. A questionnaire containing the DC of the diagnoses, applied by two nurses with expertise in cardiology, was used for clinical validation. To validate Decreased Cardiac Output ND were included patients with left ventricle ejection fraction  45% whose scores, according to the Boston criteria for classification of DHF, were 8 or higher were included in the study. To validate Fluid Volume Excess ND were included patients with systolic or diastolic dysfunction. Results of validate Decreased Cardiac Output ND: A total of 29 patients with mean age of 61+14 years; 15 (51%) male patients; and patients with mean ejection fraction of 28%+9 were included. Based on the reliability index (R) between the experts, the major DC (R ≥ 0.80) for the validation of the ND were fatigue (R=1), decreased left ventricle ejection fraction (R=1), dyspnea (R=0.96), edema (R= 0.95), orthopnea (R= 0.95), paroxysmal nocturnal dyspnea (R=0.88) and elevated central venous pressure (R=0.85). Minor or secondary characteristics were weight gain (R=0.78), jugular vein distension (R=0.74), palpitations (R=0.71), oliguria (R=0.67), cough (R=0.63), cold clammy skin (R=0.61) and changes in skin color (R=0.52). Results of validate Fluid Volume Excess ND: A total of 32 patients with mean age of 60.5+14.3 years; 17 (53%) male patients; and patients with mean ejection fraction of 31%+11.5 were included. Based on the reliability index (R) between the experts, the major DC (R ≥ 0.80) for the validation of the fluid overload ND were dyspnea (R=0.97), orthopnea (R=0.95), edema (R= 0.91), positive hepatojugular reflux (R=0.90), paroxysmal nocturnal dyspnea (R=0.88), pulmonary congestion (R=0.87) and elevated central venous pressure (R=0.85). Minor or secondary characteristics were weight gain (R=0.79), hepatomegaly (R=0.78), jugular vein distension (R=0.76), rales (R=0.66), oliguria (R=0.63) and low hematocrit and hemoglobin levels (R=0.51).Conclusion: This study showed that the major defining characteristics with R between 0,50 and 1 were validated for the diagnoses of decreased cardiac output or Fluid Volume Excess in patients with DHF. / Introducción: Débito Cardíaco Disminuido y Volumen Excesivo de Líquidos son los principales diagnósticos de Enfermería (DE) presentes en pacientes admitidos con insuficiencia cardiaca (IC) descompensada. La evaluación y determinación de las características definidoras (CD) de estos diagnóstico son fundamentales para orientar las intervenciones de enfermería adecuadas y recomendadas a los pacientes. La validación clínica de las CD de estos diagnósticos permanece inexplorada en el contexto de la IC descompensada. Objetivo: Validar clínicamente las CD de los DE Débito Cardíaco Disminuido y Volumen Excesivo de Líquidos en pacientes con IC descompensada. Métodos: Estudio transversal contemporáneo, realizado de enero a junio de 2007, en hospital universitario en Porto Alegre, Rio Grande do Sul, Brasil. Para la validación clínica, se utilizó un instrumento conteniendo las CD de los diagnósticos, aplicado por dos enfermeras peritas en cardiología. Se incluyeron pacientes con fracción de eyección del ventrículo izquierdo  45% y que obtuvieron ocho o más puntos, conforme a los criterios de Boston para la clasificación de IC descompensada. Para la validacíon de el DE Volume Excessivo de Líquidos se incluyeron pacientes com con disfunción sistólica o diastólica. Resultados de la validación de el diagnóstico Débito Cardíaco Diminuído: Se incluyeron 29 pacientes con edad media de 61±14 años; 15 (51%) del sexo masculino; fracción de eyección media del 28%±9. Conforme a la tasa de fidedignidad (R) entre las peritas, las CD consideradas mayores (R ≥ 0,80) para la validación del diagnóstico fueron la fatiga (R=1), la fracción de eyección del ventrículo izquierdo reducida (R=1), la disnea (R=0,96), el edema (R+0,95), la ortonea (R=0,95), la disnea paroxística nocturna (R=0,88) y la presión venosa central elevada (R=0,85). Las características consideradas como menores o secundarias fueron la ganancia de peso (R=0,78), la distensión de la vena yugular (R=0,74), las palpitaciones (R=0,71), la oliguria (R=0,67), la tos (R=0,63), la piel fría y pegajosa (R=0,61) y los cambios en el color de la piel (R=0,52). Resultados de la validación de el diagnóstico Volumen Excesivo de Líquidos: Se incluyeron 32 pacientes con edad media de 60,5±14,3 años; 17 (53%) del sexo masculino; fracción de eyección media de 31%±11,5. Siguiendo la tasa de fidedignidad (R) entre las peritas, las CD consideradas mayores (R ≥ 0,80) para la validación del diagnóstico Volumen Excesivo de Líquidos fueron la disnea (R=0,97), la ortonea (R=0,95), el edema (R=0,91), el reflujo hepatoyugular positivo (R=0,90), la disnea paroxística nocturna (R=0,88), la congestión pulmonar (R=0,87) y la presión venosa central elevada (R=0,85). Las características consideradas como menores o secundarias fueron la ganancia de peso (R=0,79), la hepatomegalia (R=0,78), la distensión de la vena yugular (R=0,76), las crepitaciones (R=0,66), la oliguria (R=0,63) y el hematocrito y hemoglobina disminuidos (R=0,51). Conclusión: Se demostró, en este estudio, que las características definidoras con R entre 0,50 y 1 fueron validadas para el diagnóstico Débito Cardíaco Disminuido o Volumen Excesivo de Líquidos en pacientes con IC descompensada.