Pan-aortic hybrid treatment of mega-aorta syndrome

Hybrid procedures combining traditional open and newer endovascular techniques are increasingly used to treat complex aortic disease. We present a novel approach for total aortic replacement, including hybrid repair of the arch and thoracoabdominal aorta, in a patient with “mega-aorta syndrome.” A two-stage approach using a valve-sparing aortic root replacement, total arch replacement (stage I elephant trunk), and left carotid-axillary bypass was used to treat the root, proximal-mid arch, and left subclavian aneurysmal pathology. This was followed by a hybrid distal arch/Extent II thoracoabdominal aneurysm repair 3 months later. After 15 months follow-up, the patient remains asymptomatic with an intact repair, no endoleak, and normal ventricular and aortic valve function. This case demonstrates a novel “pan-aortic” hybrid approach for repair of extensive thoracic aortic disease

Adsorption studies of non-ionic surfactants at different vegetable oil-water interfaces

The adsorption studies of non-ionic surfactants (tween 20, tween 40 and tween 80) were conducted at olive oil-water, sunflower oil-water and corn oil-water interfaces by ring detachment method with a du Nouy Tensiometer at 20 °C. A decrease in interfacial tension with an increase in surfactant concentration was observed at all the oil-water interfaces under investigation. Surface excess was calculated from Gibb’s equation while area per molecule was computed from surface excess. Surface pressure-area curves were plotted to study the states of films formed. On close examination of π-A graphs, it was indicated that all the graphs have three distinct parts. The extreme left portion (a) of the graphs represents condensed state, called solid film region, the curved region (b) of the π-A graphs corresponds to liquid film region, while the gaseous film region (c) is indicated by the shallow right hand part of the curves. The solid film region was more prominent in corn oil-water system while a more distinct gaseous film region was observed in olive oil-water system than in other oil-water systems studied. However, liquid film region was observed in all the systems investigated. The observed difference in the behaviour of surfactants at different vegetable oil-water interfaces could be attributed to the difference in types of interacting forces between the surfactant molecules and various vegetable oil phasesColegio de Farmacéuticos de la Provincia de Buenos Aire

Adsorption studies of non-ionic surfactants at different vegetable oil-water interfaces

The adsorption studies of non-ionic surfactants (tween 20, tween 40 and tween 80) were conducted at olive oil-water, sunflower oil-water and corn oil-water interfaces by ring detachment method with a du Nouy Tensiometer at 20 °C. A decrease in interfacial tension with an increase in surfactant concentration was observed at all the oil-water interfaces under investigation. Surface excess was calculated from Gibb’s equation while area per molecule was computed from surface excess. Surface pressure-area curves were plotted to study the states of films formed. On close examination of π-A graphs, it was indicated that all the graphs have three distinct parts. The extreme left portion (a) of the graphs represents condensed state, called solid film region, the curved region (b) of the π-A graphs corresponds to liquid film region, while the gaseous film region (c) is indicated by the shallow right hand part of the curves. The solid film region was more prominent in corn oil-water system while a more distinct gaseous film region was observed in olive oil-water system than in other oil-water systems studied. However, liquid film region was observed in all the systems investigated. The observed difference in the behaviour of surfactants at different vegetable oil-water interfaces could be attributed to the difference in types of interacting forces between the surfactant molecules and various vegetable oil phasesColegio de Farmacéuticos de la Provincia de Buenos Aire

Risk factors for 1-year mortality after thoracic endovascular aortic repair

ObjectiveThoracic endovascular aortic repair, although physiologically well tolerated, may fail to confer significant survival benefit in some high-risk patients. In an effort to identify patients most likely to benefit from intervention, the present study sought to determine the risk factors for 1-year mortality after thoracic endovascular aortic repair.MethodsA retrospective review was performed on prospectively collected data from all patients undergoing thoracic endovascular aortic repair from 2002 to 2010 at a single institution. Univariate analysis and multivariate Cox proportional hazards regression analysis were used to identify risk factors associated with mortality within 1 year after thoracic endovascular aortic repair.ResultsDuring the study period, 282 patients underwent at least 1 thoracic endovascular aortic repair; index procedures included descending aortic repair (n = 189), hybrid arch repair (n = 55), and hybrid thoracoabdominal repair (n = 38). The 30-day/in-hospital mortality was 7.4% (n = 21) and the overall 1-year mortality was 19% (n = 54). Cardiopulmonary pathologies were the most common cause of nonperioperative 1-year mortality (22%, n = 12). Multivariate modeling demonstrated 3 variables independently associated with 1-year mortality: age older than 75 years (hazard ratio, 2.26; P = .005), aortic diameter greater than 6.5 cm (hazard ratio, 2.20; P = .007), and American Society of Anesthesiologists class 4 (hazard ratio, 1.85; P = .049). A baseline creatinine greater than 1.5 mg/dL (hazard ratio, 1.79; P = .05) and congestive heart failure (hazard ratio, 1.87; P = .08) were also retained in the final model. These 5 variables explained a large proportion of the risk of 1-year mortality (C statistic = 0.74).ConclusionsAge older than 75 years, aortic diameter greater than 6.5 cm, and American Society of Anesthesiologists class 4 are independently associated with 1-year mortality after thoracic endovascular aortic repair. These clinical characteristics may help risk-stratify patients undergoing thoracic endovascular aortic repair and identify those unlikely to derive a long-term survival benefit from the procedure

Intrathoracic subclavian artery aneurysm repair in the thoracic endovascular aortic repair era

ObjectiveIntrathoracic subclavian artery aneurysms (SAAs) are rare aneurysms that often occur in association with congenital aortic arch anomalies and/or concomitant thoracic aortic pathology. The advent of thoracic endovascular aortic repair (TEVAR) methods may complement or replace conventional open SAA repair. Herein, we describe our experience with SAA repair in the TEVAR era.MethodsA retrospective review was performed of all intrathoracic SAAs repaired at a single institution since United States Food and Drug Administration approval of TEVAR in 2005.ResultsNineteen patients underwent 20 operations to repair 22 (13 native, nine aberrant) SAAs with an intrathoracic component. Mean SAA diameter was 3.1 cm (range, 1.6-6.0 cm). Mean patient age was 57 years (range, 24-80 years). Twenty-one percent (n = 4) of patients had a connective tissue disorder (two Loeys-Dietz, two Marfan). Thirty-six percent (n = 8) of SAAs were repaired by open techniques and 64% (n = 14) via a TEVAR-based approach. All TEVAR cases required proximal landing zone in the aortic arch (zone 0-2), and revascularization of at least one arch vessel was required in 83% (10/12) of patients. Concomitant repair of associated aortic pathology was performed in 50% (n = 10) of operations. Thirty-day/in-hospital rates of death, stroke, and permanent paraplegia/paraparesis were 5% (n = 1), 5% (n = 1), and 0%, respectively. Over mean (standard deviation) follow-up of 24 (21) months, 16% (n = 3) of patients required reintervention for subclavian artery bypass graft revision (n = 2) or type II endoleak (n = 1).ConclusionsThis is the largest single-institution series to date of TEVAR for SAA repair. Modern endovascular techniques expand SAA repair options with excellent results. The majority of SAAs and nearly all aberrant SAAs (Kommerell's diverticulum) can now be repaired using a TEVAR-based approach without the need for sternotomy or thoracotomy

Adsorption studies of non-ionic surfactants at different vegetable oil-water interfaces

The adsorption studies of non-ionic surfactants (tween 20, tween 40 and tween 80) were conducted at olive oil-water, sunflower oil-water and corn oil-water interfaces by ring detachment method with a du Nouy Tensiometer at 20 °C. A decrease in interfacial tension with an increase in surfactant concentration was observed at all the oil-water interfaces under investigation. Surface excess was calculated from Gibb’s equation while area per molecule was computed from surface excess. Surface pressure-area curves were plotted to study the states of films formed. On close examination of π-A graphs, it was indicated that all the graphs have three distinct parts. The extreme left portion (a) of the graphs represents condensed state, called solid film region, the curved region (b) of the π-A graphs corresponds to liquid film region, while the gaseous film region (c) is indicated by the shallow right hand part of the curves. The solid film region was more prominent in corn oil-water system while a more distinct gaseous film region was observed in olive oil-water system than in other oil-water systems studied. However, liquid film region was observed in all the systems investigated. The observed difference in the behaviour of surfactants at different vegetable oil-water interfaces could be attributed to the difference in types of interacting forces between the surfactant molecules and various vegetable oil phasesColegio de Farmacéuticos de la Provincia de Buenos Aire

Capture and 3D culture of colonic crypts and colonoids in a microarray platform

Crypts are the basic structural and functional units of colonic epithelium and can be isolated from the colon and cultured in vitro into multi-cell spheroids termed “colonoids”. Both crypts and colonoids are ideal building blocks for construction of an in vitro tissue model of the colon. Here we proposed and tested a microengineered platform for capture and in vitro 3D culture of colonic crypts and colonoids. An integrated platform was fabricated from polydimethylsiloxane which contained two fluidic layers separated by an array of cylindrical microwells (150-μm diameter, 150-μm depth) with perforated bottoms (30-μm opening, 10-μm depth) termed “microstrainers”. As fluid moved through the array, crypts or colonoids were retained in the microstrainers with a >90% array-filling efficiency. Matrigel as an extracellular matrix was then applied to the microstrainers to generate isolated Matrigel pockets encapsulating the crypts or colonoids. After supplying the essential growth factors, epidermal growth factor, Wnt-3A, R-spondin 2 and noggin, 63±13% of the crypts and 77±8% of the colonoids cultured in the microstrainers over a 48–72 h period formed viable 3D colonoids. Thus colonoid growth on the array was similar to that under standard culture conditions (78±5%). Additionally the colonoids displayed the same morphology and similar numbers of stem and progenitor cells as those under standard culture conditions. Immunofluorescence staining confirmed that the differentiated cell-types of the colon, goblet cells, enteroendocrine cells and absorptive enterocytes, formed on the array. To demonstrating the utility of the array in tracking the colonoid fate, quantitative fluorescence analysis was performed on the arrayed colonoids exposed to reagents such as Wnt-3A and the γ-secretase inhibitor LY-411575. The successful formation of viable, multi-cell type colonic tissue on the microengineered platform represents a first step in the building of a “colon-on-a-chip” with the goal of producing the physiologic structure and organ-level function of the colon for controlled experiments

An Efficient Lightweight Image Encryption Scheme Using Multichaos

With an immense increase in Internet multimedia applications over the past few years, digital content such as digital images are stored and shared over global networks, the probability for information leakage and illegal modifications to the digital content is at high risk. These digital images are transferred using the network bandwidth; therefore, secure encryption schemes facilitate both information security and bandwidth issues. Hence, a state-of-the-art lightweight information security methodology is required to address this challenge. The main objective of this work is to develop a lightweight nonlinear mechanism for digital image security using chaos theory. The proposed scheme starts by changing a plain image into an encrypted image to improve its security. A block cipher, using lightweight chaos, has been added to achieve this objective for digital image security. We utilized multiple chaotic maps to generate random keys for each channel. Also, Arnold cat map and chaotic gingerbread map are used to add confusion and diffusion. During the permutation stage, image pixels are permuted, while in diffusion stage, pixels are distorted utilizing gingerbread map to add more security. The proposed scheme has been validated using different security parameter tests such as correlation coefficient tests (CC), whose results have been observed closer to zero and information entropy (IE) value is 7.99, respectively, which is almost equal to the ideal value of 8. Moreover, number of pixels changing rate (NPCR) obtained value is higher than 99.50%, while the unified average changing intensity (UACI) is 33.33. Other parameters such as mean absolute error (MAE), mean square error (MSE), lower value of peak to signal noise ratio (PSNR), structural content (SC), maximum difference (MD), average difference (AD), normalized cross-correlation (NCC), and histogram analysis (HA) is tested. The computed values of the proposed scheme are better. The achieved results after comparison with existing schemes highlight that the proposed scheme is highly secure, lightweight, and feasible for real-time communications