634 research outputs found
Effect of Grafted Spiropyran on the Solubility and Film Properties of Photochromic Amylose
Four photochromic spiropyran-amylose (ASP) biobased polymers with different spiropyran (SP) grafting density, DS, ASP(10) (DS = 0.12), ASP(40) and ASP(40)PA(60) (DS = 0.40), and ASP(100) (DS = 0.97), are synthesized through azide-alkyne cycloaddition of an alkynyl-functional SP derivative onto C6-azidated-amylose (AN(3)), where the unconverted azide in ASP(40)PA(60), ASP(100), and the AN(3) precursor are quenched by clicking with propargyl alcohol (PA). All ASPs are poorly soluble in trifluoroethanol, ethanol, and water but soluble in dimethyl sulfoxide, N,N-dimethylformamide, and hexafluoroisopropanol irrespective of UV irradiation, switching reversibly the grafted SP into zwitterionic merocyanine (MC). Only ASP(10) and ASP(40) are slightly soluble in the low polarity tetrahydrofuran, with ASP(40) showing a marked photochromism and reduction of solubility on SP -> MC switching. The photochromism in solution is preserved in the solid state, although with significant differences between the still relatively fast SP -> MC photoisomerization and the much slower thermal retro-isomerization. The dynamics of both processes, evaluated in a thin spin-coated ASP(100) film and a thicker ASP(40) photoswitchable coating on glass and paper, is more clearly affected than in solution by the grafting density. Switching the nearly apolar SP into the zwitterionic MC does not significantly affect wettability of the slightly hydrophobic ASP(40) coating
Stem cells and new intervention measures as emerging therapy in cardiac surgery
Cardiovascular disease (CVD) presents a great burden for elderly patients, their caregivers, and health systems. Structural and functional alterations of vessels accumulate throughout life, culminating in increased risk of developing CVD. Several inflammatory pathway are involved in vascular ageing. The growing elderly population worldwide highlights the need to understand how aging promotes CVD in order to develop new strategies to confront this challenge. In this review we analyzed the role of stem cells and new intervention measures as emerging drugs for vascular aging
Mid-Term Outcome of Mitral Valve Repair and Coronary Artery Bypass Grafting for Ischemic or Degenerative Mitral Regurgitation
Aim of the study. To verify the impact of the etiology of mitral valve regurgitation on a 5-year outcome after repair and concomitant coronary artery bypass grafting (CABG).
Methods. One hundred and eleven consecutive patients (mean age of 69±8 years) who underwent mitral valve repair, 65 for ischemic and 46 for degenerative mitral regurgitation, and concomitant CABG, were retrospectively analyzed. The mean follow-up was 40±28 (9-104) months. Five-year survival (including operative mortality), and survival free from events (postoperative low output syndrome, progression of mitral regurgitation, onset or worsening of congestive heart failure, recurrence of myocardial infarction, and the need for mitral valve replacement) were analyzed.
Results. Compared with degenerative, ischemic mitral regurgitation was associated with a higher incidence of previous myocardial infarction (P<0.0001), left ventricular ejection fraction (LVEF) <0.45 (P<0.0001), and more diseased coronary vessels per patient (P<0.0001). Five-year all-cause mortality was 18% (20/111). Independent predictors of mortality were older age at operation (P=0.0008), LVEF<0.45 (P=0.04), and the ischemic etiology of mitral regurgitation (P=0.03). At five years, survival was 69%±7.6% for ischemic versus 87%±6.5% for degenerative etiology (P=0.03); event-free survival was 58%±8.4% versus 75%±8% (P=0.02), and freedom from late cardiac death was 85%±6.6% versus 100% (P=0.02). Freedom from mitral valve reoperation was 97±2.4%.
Conclusions. Ischemic mitral regurgitation “per se” predicted limited survival and event-free survival. Left ventricular dysfunction is frequently associated with the ischemic etiology. An early surgical indication to prevent left ventricular dysfunction could be important to improve the mid-term outcom
Progress on the realization of a LoRa® based communication system for atmospheric monitoring probes
The work presents the progress on the realization of the communication system realized for atmospheric monitoring probes. The realization of a link based on the Long Range (LoRa®) technology to connect and exchange data between the probes and the base station located on the ground is the potential adopted solution. After a brief description of the whole project, the realization of the first prototypal transmission system using Adafruit® Feather 32u4 LoRa Radio RFM95 embedded modules is described. First propagation measurements and results are presented
Surgical "elephant trunk" arch replacement with a branched arch prosthesis: two alternative operative techniques
Introduction: Elephant trunk repair of the aortic arch cannot be performed with a branched prosthesis. Aim: We conceived two different modifications of the original technique to perform an arch replacement with a branched graft, while arranging an adequate landing zone for a subsequent thoracic endovascular aortic repair, without the need of dedicated material. Material and methods: Eight consecutive patients underwent arch replacement with one of our techniques. Five were emergency patients with acute aortic dissection, and 3 suffered chronic expansive disease. The "modified elephant trunk" includes a separate anastomosis of an endo-luminal prosthetic segment in the descending aorta. Subsequently, the branched arch prosthesis is anastomosed to the distal aortic stump with the attached trunk. In the "prophylactic debranching", a tail is left on the distal end of the arch prosthesis, so that the branches for the supra-aortic vessels will remain displaced proximally, allowing a "zone 1" available for landing. Results: Three patients experienced transient cerebral deficits (1 transient ischemic attack and post-operative delirium in 2 cases), 1 required re-operation for bleeding and 2 needed prolonged intubation. One died of multi-organ failure. Conclusions: Both techniques proved to be easily reproducible, and allow an adequate landing zone for a subsequent endovascular procedure, while retaining the advantages of using a tetra-furcated prosthesis. They are a viable alternative when a hybrid prosthesis cannot be implanted
Characterization of the Use and Occupation of Soil on Rural Properties Using Remotely Piloted Aircraft Systems - RPAS
The use of remotely piloted aircraft systems allows for practicality in the collection and monitoring of study areas or in the development of rehabilitation projects for degraded areas. As such, this technology is gaining space as an alternative for applications in studies and surveys of several areas. This work is justified by the demand for projects and the search for practical alternatives that will enable the framing of rural properties according to the new Brazilian Forestry Code (CodĂgo Florestal Brasileiro) and its environmental recovery plans (Plano de Recuperação Ambiental). The objective of this study is therefore to evaluate the use of a Remotely Piloted Aircraft System in the monitoring of a rural property, seeking to include it in the framework of the Brazilian Forestry Code. To accomplish this work, information samples were taken in an area of 30.19 ha of a rural property with the use of a Remotely Piloted Aircraft System - RPAS. After the data collection, the images were treated using the QGis software and through the generation of an ortho-mosaic, which enabled the data to be analyzed and interpreted. With the interpretation of land use and occupation data and with the generation of maps of land use and occupation, a diagnosis of the current situation of the area can be obtained. In a second phase, maps were created to include the property in the current legislative framework, seeking its regularization. After the completion of this work, the conclusion can be drawn that the use of a Remotely Piloted Aircraft System - RPAS is viable and enables the monitoring of rural areas with efficiency and speed
Long-term follow-up of device-assisted clampless off-pump coronary artery bypass grafting compared with conventional on-pump technique
Study objective: To evaluate the long-term outcomes of clampless off-pump coronary artery bypass grafting (C-OPCAB) compared with conventional on-pump double clamping coronary artery bypass grafting (C-CABG). Methods: From October 2006 to December 2011, 366 patients underwent isolated coronary artery bypass grafting. After propensity score matching of preoperative variables, 143 pairs were selected who received C-OPCAB with the use of device-assisted PAS-Port proximal venous graft anastomoses or C-CABG, performed by the same surgeon experienced in both techniques. Data of the two groups of patients were retrospectively analyzed up to 14 years of follow-up. Results: As compared with C-OPCAB, in the C-CABG patients, the performed number of grafts per patient was higher (2.9 +/- 0.5 vs. 2.6 +/- 0.6, p-value 0.0001). At 14 years, overall survival, including in-hospital death, was 64 +/- 4.7% for the C-OPCAB vs. 55 +/- 5.5% for the C-CABG, freedom from overall MACCEs 51 +/- 6.2% vs. 41 +/- 7.7%, and from late cardiac death 94 +/- 2.4% vs. 96 +/- 2.2% (p-value not significant, for all comparisons). No significant statistical differences were observed in the actual rates of adverse events during follow-up. Independent predictors of survival were advanced age at operation (p-value 0.001) and a lower mean value of preoperative left ventricular ejection fraction (p-value 0.015). Conclusions: Our single-center study analysis suggests that clampless OPCAB using device-assisted proximal anastomoses proved to be not inferior to double-clamping CABG in the long-term follow-up, provided that involved surgeons are familiar with both techniques. These conclusions are supported by a large and long-term follow-up period, eliminating potential bias, i.e., by means of the propensity score matching and analyzing single-surgeon experience
Calcium Supplementation Increases Bone Mass in GH-Deficient Prepubertal Children during GH Replacement
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