Color and brightness at work: Shedding some light on mind wandering.

Introduction: Occupational hazards are partly caused by the physical factors of the work environment, among which are ambient color and brightness, which can interfere with cognitive performance. Especially in modern work environments, performance relies heavily on cognitive functions such as attention, and an important factor in disrupting sustained attention is mind wandering (MW). This study aimed to investigate the effects of white and blue colors with two brightness levels on sustained attention and brain electrophysiology.

Antimicrobial peptides with anticancer activity: Today status, trends and their computational design.

Some antimicrobial peptides have been shown to be able to inhibit the proliferation of cancer cell lines. Various strategies for treating cancers with active peptides have been pursued. According to the reports, anticancer peptides are important therapeutic peptides, which can act through two distinct pathways: they either just create pores in the cell membrane, or they have a vital intracellular target.

Massive TAVR: Complex Transcatheter Aortic Valve Replacement in the Setting of an Enormous Adnexal Mass.

A 65-year-old woman with a large adnexal mass was found to have severe bicuspid aortic valve stenosis. Transcatheter aortic valve replacement was chosen rather than surgical aortic valve replacement because of concerns over risks. We demonstrate the value of pre-operative transcatheter aortic valve replacement before prompt noncardiac surgery.

Bicuspid Aortic Valve-Associated Ascending Thoracic Aortic Aneurysm: Patient-Specific Finite Element Analysis.

Background: Elective repair of bicuspid aortic valve (BAV)-associated ascending thoracic aortic aneurysm (aTAA) is recommended at lower size limits than tricuspid aortic valve (TAV)-associated aTAA. Rupture/dissection can occur when wall stress exceeds wall strength. Previously, a validated computational method was developed for determining aTAA wall stress, but to date this method has not applied to a patient-specific BAV aTAA.

Biomechanics of Failed Pulmonary Autografts Compared to Native Aortic Roots.

Background: Progressive autograft dilatation after a Ross operation suggests that remodeling does not effectively reproduce native aortic root biomechanics. In the first of this two-part series, we compared mechanical properties of explanted autografts to pulmonary roots at pulmonary pressures. The goal of this study was to compare mechanical properties of explanted autografts to native aortic roots at systemic pressures.

Biomechanics of Failed Pulmonary Autografts Compared With Normal Pulmonary Roots.

Background: Progressive dilatation of pulmonary autografts after the Ross operation may reflect inadequate remodeling of the native pulmonary root to adapt to systemic circulation. Understanding the biomechanics of autograft root dilatation may aid designing strategies to prevent dilatation. We have previously characterized normal human pulmonary root material properties; however, the mechanical properties of failed autografts are unknown.

Patient-specific finite element analysis of ascending thoracic aortic aneurysm.

Background And Aim Of The Study: Rupture/dissection of ascending thoracic aortic aneurysm (aTAA) is a cardiovascular emergency. Elective surgical repair is primarily based on maximum diameter, but complications have occurred under the size limits for surgical intervention. aTAA wall stress may be a better predictor of patient-specific rupture risk, but cannot be directly measured in vivo.

Human pulmonary autograft wall stress at systemic pressures prior to remodeling after the Ross procedure.

Background And Aim Of The Study: Remodeling of the pulmonary autograft upon exposure to systemic pressure can lead to progressive dilatation and aneurysmal pathology. Remodeling is driven by changes in autograft wall stress upon exposure to systemic pressure; however, the magnitude of these changes is unknown. Previously, a porcine autograft finite element model was developed to determine wall stress, but the porcine and human material properties differed significantly.

Biomechanical properties of human ascending thoracic aortic aneurysms.

Background: Surgical management of ascending thoracic aortic aneurysms (aTAAs) relies on maximum diameter, growth rate, and presence of connective tissue disorders. However, dissection and rupture do occur in patients who do not meet criteria for surgical repair. This study investigated the mechanical properties of aTAAs compared with normal human ascending aortas for eventual development of biomechanical aTAA risk models.

Material properties of CorCap passive cardiac support device.

Background: Myocardial function deteriorates during ventricular remodeling in patients with congestive heart failure (HF). Ventricular restraint therapy using a cardiac support device (CSD) is designed to reduce the amount of stress inside the dilated ventricles, which in turn halts remodeling. However, as an open mesh surrounding the heart, it is unknown what the mechanical properties of the CSD are in different fiber orientations.

Regional mechanical properties of human pulmonary root used for the Ross operation.

Background And Aim Of The Study: Significant dilation of the pulmonary autograft after the Ross operation is problematic and requires reoperation. Autograft remodeling occurs in response to the immediate rise in pressure and consequent wall stress. The stress-strain response of the pulmonary root plays an important role in understanding the structural and functional changes of the autograft following the Ross procedure.

Acute type A aortic dissection intimal tears by 64-slice computed tomography: a role for endovascular stent-grafting?

Aim: The goal of this study was to identify physical characteristics of primary intimal tears in patients arriving to the hospital alive with acute type A aortic dissection using 64-multislice computerized tomography (MSCT) in order to determine anatomic feasibility of endovascular stent-grafting (ESG) for future treatment.

Methods: Radiology database was screened for acute type A aortic dissection since the time of acquisition of the 64-slice CT scanner and cross-referenced with surgical database. Seventeen patients met inclusion criteria.

Hemodynamic determinants of aortic dissection propagation by 2D computational modeling: implications for endovascular stent-grafting.

Aim: Aortic dissection is a life-threatening aortic catastrophe where layers of the aortic wall are separated allowing blood flow within the layers. Propagation of aortic dissection is strongly linked to the rate of rise of pressure (dp/dt) experienced by the aortic wall but the hemodynamics is poorly understood. The purpose of this study was to perform computational fluid dynamics (CFD) simulations to determine the relationship between dissection propagation in the distal longitudinal direction (the tearing force) and dp/dt.

Correlation of calcification on excised aortic valves by micro-computed tomography with severity of aortic stenosis.

Background And Aim Of The Study: The quantification of incidentally found aortic valve calcification on computed tomography (CT) is not performed routinely, as data relating to the accuracy of aortic valve calcium for estimating the severity of aortic stenosis (AS) is neither consistent nor validated. As aortic valve calcium quantification by CT is confounded by wall and coronary ostial calcification, as well as motion artifact, the ex-vivo micro-computed tomography (micro-CT) of stenotic aortic valves allows a precise measurement of the amounts of calcium present. The study aim, using excised aortic valves from patients with confirmed AS, was to determine if the amount of calcium on micro-CT correlated with the severity of AS.

Robotically controlled ablation for atrial fibrillation: the first real-world experience in Africa with the Hansen robotic system.

Background: We report the first single-centre experience in Africa with the Sensei X robotic navigation system in an unselected subset of patients with atrial fibrillation (AF).

Methods: Data were recorded prospectively of all consecutive patients who underwent robotically assisted catheter ablation therapy using the Sensei X robotic navigation system at the Christiaan Barnard Memorial Hospital, Cape Town, South Africa, from July 2009 to July 2010. Outcomes were defined at one and nine months.

Biomechanical comparison of human pulmonary and aortic roots.

Objective: Significant dilation of the pulmonary autograft is problematic after the Ross operation and may require reoperation. Pulmonary autograft remodelling occurs in response to the immediate rise in pressure and consequently wall stress. Stress-strain response of the pulmonary root plays an important role in understanding autograft function and remodelling following the Ross procedure.

Incidental aortic valve calcification on CT scans: significance for bicuspid and tricuspid valve disease.

Rationale And Objectives: The aim of this study was to evaluate the role of incidental aortic valve calcification on routine computed tomographic scans as a marker for stenosis, as assessed by echocardiography, in patients with bicuspid aortic valve (BAV) and tricuspid aortic valve.

Materials And Methods: Computed tomographic and echocardiographic studies were retrospectively reviewed for 182 consecutive, unselected patients and 426 patients identified by a record search for "aortic valve calcification." Location and severity of valve calcification were correlated with aortic valve morphology and stenosis.

Comparison of mechanical properties of human ascending aorta and aortic sinuses.

Background: Computational finite element models of the aortic root have previously used material properties of the ascending aorta to describe both aortic sinuses and ascending aorta. We have previously demonstrated significant material property differences between ascending aorta and sinuses in pigs. However, it is unknown whether these regional material property differences exist in humans.

Operative risks and survival in veterans with severe aortic stenosis: surgery versus medical therapy.

Background: Transcatheter aortic valves were developed as an alternative to surgery for the one third to two thirds of patients with severe aortic stenosis who do not undergo aortic valve replacement. In this study, we examined reasons for medical management of aortic stenosis in relation to operative risks and outcomes for veterans with and without valve replacement.

Methods: The echocardiography database was screened from 2000 to 2007 for severe aortic stenosis.

Valve-in-valve hemodynamics of 20-mm transcatheter aortic valves in small bioprostheses.

Background: Transcatheter aortic valve (TAV) implantation is a treatment for selected patients with failing bioprostheses. We previously showed that currently available SAPIEN (Edwards Lifesciences, Irvine, CA) TAV sizes did not yield acceptable valve-in-valve (VIV) hemodynamics in small degenerated bioprostheses because optimal TAV function requires full stent expansion to its nominal size. The study objective was to determine (1) if 20-mm TAVs provide acceptable hemodynamics in small degenerated bioprostheses and (2) the effect of TAV spatial orientation on valvular hemodynamics and coronary flows.

Echo rejection score: new echocardiographic approach to diagnosis of heart transplant rejection.

Objective: The gold standard test in the diagnosis of heart transplant rejection is right ventricular (RV) myocardial biopsy, which is an invasive, time-consuming, expensive method. In an effort to find a reliable method to minimise the sequential use of myocardial biopsy, we assessed the main echocardiographic indices for the detection of allograft rejection.

Materials And Methods: Fifty myocardial specimens were examined in this prospective study, which assessed the prominent echocardiographic parameters propounded by previous studies as indicators of rejection.

The association between Chlamydia pneumoniae DNA in arherosclerotic plaque and major risk factors in patients undergoing coronary artery bypass grafting.

Background And Aim: This study was conducted to investigate the prevalence of Chlamydia pneumoniae pathogen inside the atherosclerotic plaque of patients undergoing CABG by using PCR assay and to determine whether there is any association between the presence of bacteria in atherosclerotic lesions and classical coronary risk factors.

Methods: In a cross-sectional study, 102 patients (20 to 79 years old; 73.5% male) undergoing CABG were evaluated in terms of major coronary risk factors and the presence of Chlamydia pneumoniae.