2,882 research outputs found
Diffraction Evidence for Oxygen-Vacancy Ordering in Annealed BA2YCU3O7-Delta(0.3Less-Than-Delta-or-Equal-TO0.4) Superconductors
No full textSingle-Phase 60-K Bulk Superconductor in Annealed Ba2YCu3O7-DELTA(0.3-Less-Than-Delta-Less-Than-0.4) with Correlated Oxygen Vacancies in the Cu-O Chains
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The HI-MAP scan : the use of emergency ultrasound to evaluate haemodynamically unstable patients
No full textIncludes abstract.
Includes bibliographical references
One and a half ventricle repair: clinical and animal study
Get PDFSUMMARY
Since the first description of the so called “one and a half ventricle repair”, published by Billingsly et al. in 1989 1, this type of correction has been applied to several complex congenital cardiac anomalies. The rationale underlying this repair is twofold. On one hand the aim is to reduce the blood flow to, and therefore to downsize the pre-load of, a dysfunctional or hypoplastic right ventricle (RV), considered to be unable to sustain a biventricular correction. On the other hand the one and a half ventricle repair (1.5 VR) permits to maintain a complete and physiological separation of pulmonary and systemic circulations, avoiding blood mixing and desaturation. Furthermore it represents a valid alternative to the Fontan circulation in the setting of a less but still functioning RV, with the advantage to provide a pulsatile pulmonary blood flow and to prevent systemic venous hypertension 2,3. One and a half ventricle repair consists of bidirectional cavo-pulmonary shunt (BCPS) in addition to complete closure of intracardiac communications, associated or not with repair of other congenital heart defects. It can be appropriate for a wide spectrum of congenital anomalies, provided that the RV is large enough to manage the blood supply from the inferior vena cava. However, feasibility in adult population is being explored 1,4.
This study has divided in two parts:
1. Clinical study 2. Experimental study in animals.
In clinical study we have reviewed our institutional experience with 1.5 VR to evaluate early and long term results and explore the impact of associated cardiac malformations on outcomes of the one and a half ventricle repair. Animal study in rabbits was conducted to evaluate the effect of a pulsatile venous flow pattern in superior vena cava and to understand an immediate & after pharmacologically induced stress test the hemodynamic changes in superior vena cava, right atrium, right ventricle, pulmonary artery and inferior vena cava district.
A. Clinical study
Methods
All patients who underwent one and a half ventricle repair between March 1994 and January 2012 were included. All available clinical and operative data were reviewed. Patients were divided in: Group A - patients with right ventricle hypoplasia/dysfunction and malformations of tricuspid or pulmonary valves; Group B - patients with associated complex malformations involving other cardiac structures.
Results
This is an 18 years retrospective clinical review of 24 consecutive patients who underwent one and a half ventricle repair at our Institution. Mean age at repair was 11.9 years (range 4 months – 66.8 years). Mean TV annulus Z-score was -3.2 (range -6.2 to 3.6). Mean pulmonary vascular resistance was 1.75 U/m2 (range 1.0 to 3.0). Three patients had heterotaxy syndrome. Sixteen patients underwent previous cardiac operation, one of these had a Fontan operation.
There was no death at operation. Postoperative complications occurred in 19 patients (79 %), and were: chylothorax/chylopericardium (n=7), BAV III (n=2), arrhythmias (n=7), renal failure (n=4), heart failure (n=4), cardiac/pleural effusion (n=11), SVC syndrome (n=2), pulmonary infection (n=3), hemi diaphragm paralysis that required diaphragm plasty (n=1), SVC thrombosis with PE (n=1). Five patients required definitive PM implantation. All patients were discharged home alive and well, after a mean hospital stay of 32 ± 29 days. At a mean follow up of 8.3 years (range 1 month – 17.9 years, FU completeness: 96 %), there were 2 late deaths (1 non cardiac related). Among survivors, functional status was NYHA class I in 19 patients (90.4%). Late adverse events occurred in 10 patients (43 %) including: late reoperation (n=3), one of these was a biventricular conversion; haemodynamic procedures (n=6); arrhythmias (n=2); neurological event (n=1); other complications (n=5).
Overall freedom from adverse events, surgery and interventional procedures was 56.5 %, 87 % and 73,9 % respectively. Freedom from adverse event in Group A (n=12) was 83.3 % while in Group B (n=11) was 27.3 %. Statistical analysis demonstrated that Group B had a significantly lower freedom from adverse events than Group A (p = 0.015).
B. Animal Study
Methods
Experiment was performed in experimental Rabbits. Animal care has taken according to established standard for experiment in animals.
Experimental model: RABBIT
Strain: NEW ZEALAND
Total animal number: 30
Weigh of animals:4. 5-5.5 kg
Results
1. After cavapulmonary anastomosis- SVC and PA pressure has increased but RA pressure has decreased, which proves the decrease of the pressure in inferior vena cava district.
2. After pharmacologically induced stress test: increased the pressure in superior vena cava and also increased heart rate but right ventricular, right atrial & pulmonary artery pressures were remained as same as after cavopolmonary anastomosis, as it is in resting condition.
3. That means superior vena cava pressure is always higher after cavapulmonary anastomosis but venous pressure in inferior vena cava district is constant and even lower in comparison with preoperative pressure.
4. We found no any changes of right atrial pressure, after 1.5 ventricular repair and even after pharmacologically induced stress test which proves that the inferior vena cava return is ok and no hypertension in inferior vena cava district even after stress test(good exercise tolerance), which is a very positive finding in favour of one and a half ventricle repair in comparison to Fontan type procedure.
Conclusion
After having the result of both clinical study and experiment in animals we have concluded that the 1.5 VR is a safe and valid option for surgical repair of hypoplasic, borderline or failing right ventricles as an alternative to Fontan procedure. Most patients show good functional status at follow up. This repair provides a low pressure in the inferior vena cava district and allows good early and mid-term outcomes
Reformulating the rj-McMC Algorithm for 3D Inversion of Passive Seismic Data for Near-Surface Characterization
No full textGeophysical subsurface characterization techniques could, due to their non-invasive nature, play a crucial role in the design and subsequent construction of infrastructure in urban & industrial environ- ments. Geo-data specialist company Fugro sees potential in upgrading their current ambient-seismic- noise-tomography workflow, to make use of state-of-the-art inversion schemes with the main goal of increasing the quality and accuracy of the initial-site characterization delivered to clients. In this thesis I explore the feasibility of utilizing the reverse-jump Markov chain Monte Carlo (rj-McMC) algorithm for the inversion of ambient seismic noise for characterization in urban & industrial environments. Specif- ically, testing the potential of scaling down this inversion algorithm to fit in a small scale, near-surface framework. To achieve this, I first carried out analyses to evaluate the appropriate Rayleigh wave frequency range, after which realistic noise hyperparameters, suited for this reduced scale problem, were obtained. Because of the potential exploitation of in-situ borehole measurements, I reformulated the Bayesian prior within the rj-McMC algorithm to implement these constraining shear wave velocity values appropriately. I conducted extensive synthetic experiments to gain insight into the behavior of this adapted algorithm, from which it was concluded that the inherent dynamic discretization partially prevents these constraints from being implemented to their full extent. Nevertheless, promising results lead me to conclude that the use of the rj-McMC algorithm for application in near-surface urban & industrial environments is feasible.Applied Geophysics | IDEA Leagu
The perils and merits (or the Good, the Bad and the Ugly) of DNA barcoding of sponges – a controversial discussion
Get PDFDNA barcodes are defined as signature sequences used to identify unknown specimens. They have been proposed as a means to quickly solve the taxonomical impediment, through an organised and highly structured effort, using the same
part of the mitochondrial sub-unit I of the Cytochrome c oxidase gene to identify all species of the planet. There has been much debate about the uses and misuses of DNA for taxonomy, and the radical proposition of DNA barcodes has heated the debate. In this paper we present two contrasting views of how DNA barcodes may or may not help sponge taxonomy
Clowns, Fools, and Killers: An Exploration of Horror, Comedy, and Madness Through the Roles of Murderer 2 and Sir Richard Ratcliffe in William Shakespeare\u27s Richard III
Get PDFThis document is a thesis submitted in partial fulfillment of the Master of Fine Arts degree in Theatre Arts with a Concentration in Musical Theatre. It is a detailed account of author RJ Magee’s artistic and scholarly process in creating the roles of Murderer 2 and Sir Richard Ratcliffe in William Shakespeare’s Richard III. The production was performed as part of Minnesota State University, Mankato’s mainstage season in October of 2022. In five chapters, this thesis chronicles the actor’s process: a preproduction analysis, a historical and critical perspective, a rehearsal and performance journal, a post-production analysis, and a process development analysis. Appendices and works cited are included
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