Transcatheter aortic valve resection: new mechanical devices

Background To improve periprocedural outcomes of transcatheter aortic valve implantation (TAVI), transcatheter mechanical resection devices were tested for prior ablation of the aortic cusps. Methods Three mechanical transcatheter resection devices were tested in a series of native porcine (n=30) and reassembled calcified human valves (n=54). The resection time, the resected valve area, the number of released cusps, and the degree of surrounding tissue damage were measured. Afterwards, postmortem transapical-transcatheter-resections of the aortic valve in two humans were performed. Results In the native porcine hearts, the Aesculap II device demonstrated significantly shorter resection time compared to the R&R II and the Randstad devices (6.5±2.0 vs. 28.6±24.1 vs. 23.3±14.4 sec; P=0.001). However, it created more lesions in the surrounding tissue (P=0.002). The R&R II achieved a smaller number of resected cusps than the other two devices (2.7±0.7 vs. 1.1±0.7 vs. 2.4±0.5; P<0.001, respectively). It also resected a smaller area of the aortic valve (306.5±149.2 vs. 106.7±29.6 vs. 256.8±81.3 mm2; P=0.09) but a larger mean area of the resected fragments (110.3±41.5 vs. 160.7±29.6 vs. 111.5±43.9 mm2; P=0.01). The resection of the reassembled human valves demonstrated the same results between the devices regarding resection time (P=0.001) and resected area (P=0.016), but not fragment sizes (P=0.610). Finally, transapical-transcatheter-resection of aortic valve was performed in two cadavers. Conclusions Transcatheter aortic valve resection is feasible with variable aortic leaflet resection times and mild risk of lesions of the surrounding tissue

Non-volatile molecular memory elements based on ambipolar nanotube field effect transistors

We have fabricated air-stable n-type, ambipolar carbon nanotube field effect transistors (CNFETs), and used them in nanoscale memory cells. N-type transistors are achieved by annealing of nanotubes in hydrogen gas and contacting them by cobalt electrodes. Scanning gate microscopy reveals that the bulk response of these devices is similar to gold-contacted p-CNFETs, confirming that Schottky barrier formation at the contact interface determines accessibility of electron and hole transport regimes. The transfer characteristics and Coulomb Blockade (CB) spectroscopy in ambipolar devices show strongly enhanced gate coupling, most likely due to reduction of defect density at the silicon/silicon-dioxide interface during hydrogen anneal. The CB data in the ``on''-state indicates that these CNFETs are nearly ballistic conductors at high electrostatic doping. Due to their nanoscale capacitance, CNFETs are extremely sensitive to presence of individual charge around the channel. We demonstrate that this property can be harnessed to construct data storage elements that operate at the few-electron level.Comment: 6 pages text, 3 figures and 1 table of content graphic; available as NanoLetters ASAP article on the we

Large Eddy Simulation of combustion instabilities in a lean partially premixed swirled flame

This paper investigates one issue related to Large Eddy Simulations (LES) of self- excited combustion instabilities in gas-fueled swirled burners: the effects of incom- plete mixing between the gas injection and the combustion chamber. For simplicity reasons, many LES assume perfect premixing of the gases entering the combustion chamber. In practice this is rarely the case and this study addresses the question by comparing LES assuming perfect premixing and LES where the fuel jets are resolved and fuel/air mixing is explicitely computed. This is done for the Preccin- sta swirled burner which has been carefully studied experimentally at DLR. All previous LES studies of Preccinsta have assumed perfect premixing and this work demonstrates that this assumption is reasonable for stable flows but is not accept- able to predict self-excited unstable cases. This is shown by comparing LES and experimental fields in terms of mean and RMS fields of temperature, species and velocities as well as mixture fraction pdfs and unsteady activity for two regimes: a stable one at equivalence ratio 0.83 and an unstable one at 0.7

УЯЗВИМОСТИ ADS-B

В данном исследовании рассмотрим более детально, как работают системы управления воздушными потоками старого и нового по-коления, а также представим найденные во время его исследования уязвимости и наиболее серьезные риски, связанные с ними. Авиатехнологии находятся на границе нового технического прорыва, и так, как это уже случилось со смартфонами и сетями мобильной связи примерно 5-10 лет назад, новые технологии приводят к новым проблемам. На этот раз – куда более опасным

Improvement of renal function after transcatheter aortic valve replacement and its impact on survival

Background Chronic kidney disease as well as acute kidney injury are associated with adverse outcomes after transcatheter aortic valve replacement (TAVR). However, little is known about the prognostic implications of an improvement in renal function after TAVR. Methods Renal improvement (RI) was defined as a decrease in postprocedural creatinine in μmol/l of ≥1% compared to its preprocedural baseline value. A propensity score representing the likelihood of RI was calculated to define patient groups which were comparable regarding potential confounders (age, sex, BMI, NYHA classification, STS score, log. EuroSCORE, history of atrial fibrillation/atrial flutter, pulmonary disease, previous stroke, CRP, creatinine, hsTNT and NT-proBNP). The cohort was stratified into 5 quintiles according to this propensity score and the survival time after TAVR was compared within each subgroup. Results Patients in quintile 5 (n = 93) had the highest likelihood for RI. They were characterized by higher creatinine, lower eGFR, higher NYHA class, higher NT-proBNP, being mostly female and having shorter overall survival time. Within quintile 5, patients without RI had significantly shorter survival compared to patients with RI (p = 0.002, HR = 0.32, 95% CI = [0.15-0.69]). There was no survival time difference between patients with and without RI in the whole cohort (p = 0.12) and in quintiles 1 to 4 (all p > 0.16). Analyses of specific subgroups showed that among patients with NYHA class IV, those with RI also had a significant survival time benefit (p < 0.001, HR = 0.15; 95%-CI = [0.05-0.44]) compared to patients without RI. Conclusions We here describe a propensity score-derived specific subgroup of patients in which RI after TAVR correlated with a significant survival benefit

Sex‐specific genetic factors affect the risk of early‐onset periodontitis in Europeans

Aims: Various studies have reported that young European women are more likely to develop early-onset periodontitis compared to men. A potential explanation for the observed variations in sex and age of disease onset is the natural genetic variation within the autosomal genomes. We hypothesized that genotype-by-sex (G × S) interactions contribute to the increased prevalence and severity. Materials and methods: Using the case-only design, we tested for differences in genetic effects between men and women in 896 North-West European early-onset cases, using imputed genotypes from the OmniExpress genotyping array. Population-representative 6823 controls were used to verify that the interacting variables G and S were uncorrelated in the general population. Results: In total, 20 loci indicated G × S associations (P < 0.0005), 3 of which were previously suggested as risk genes for periodontitis (ABLIM2, CDH13, and NELL1). We also found independent G × S interactions of the related gene paralogs MACROD1/FLRT1 (chr11) and MACROD2/FLRT3 (chr20). G × S-associated SNPs at CPEB4, CDH13, MACROD1, and MECOM were genome-wide-associated with heel bone mineral density (CPEB4, MECOM), waist-to-hip ratio (CPEB4, MACROD1), and blood pressure (CPEB4, CDH13). Conclusions: Our results indicate that natural genetic variation affects the different heritability of periodontitis among sexes and suggest genes that contribute to inter-sex phenotypic variation in early-onset periodontitis

Block Spin Density Matrix of the Inhomogeneous AKLT Model

We study the inhomogeneous generalization of a 1-dimensional AKLT spin chain model. Spins at each lattice site could be different. Under certain conditions, the ground state of this AKLT model is unique and is described by the Valence-Bond-Solid (VBS) state. We calculate the density matrix of a contiguous block of bulk spins in this ground state. The density matrix is independent of spins outside the block. It is diagonalized and shown to be a projector onto a subspace. We prove that for large block the density matrix behaves as the identity in the subspace. The von Neumann entropy coincides with Renyi entropy and is equal to the saturated value.Comment: 20 page

Apolipoprotein E related Co-Morbidities and Alzheimer’s disease

The primary goal of advancement in clinical services is to provide a health care system that enhances an individual’s quality of life. Incidence of diabetes mellitus, cardiovascular disease and associated dementia coupled with the advancing age of the population, have led to an increase in the worldwide challenge to the healthcare system. In order to overcome these challenges prior knowledge of common, reliable risk factors and their effectors is essential. The oral health constitutes one such relatively unexplored but indispensable risk factor for aforementioned co-morbidities, in the form of poor oral hygiene and tooth loss during aging. Behavioural traits such as low education, smoking, poor diet, neglect of oral health, lack of exercise, and hypertension are few of the risk factors that are shared commonly amongst these conditions. In addition, common genetic susceptibility traits such as the apolipoprotein ɛ gene, together with an individual’s life style can also influence the development of co-morbidities such as periodontitis, atherosclerosis/stroke, diabetes, and Alzheimer’s disease. This review specifically addresses the susceptibility of apolipoprotein ε gene allele 4 as the plausible commonality for the etiology of co-morbidities that eventually result from periodontal diseases and ultimately progress to dementia

SATB1, genomic instability and Gleason grading constitute a novel risk score for prostate cancer

Current prostate cancer risk classifications rely on clinicopathological parameters resulting in uncertainties for prognostication. To improve individual risk stratification, we examined the predictive value of selected proteins with respect to tumor heterogeneity and genomic instability. We assessed the degree of genomic instability in 50 radical prostatectomy specimens by DNA-Image-Cytometry and evaluated protein expression in related 199 tissue-microarray (TMA) cores. Immunohistochemical data of SATB1, SPIN1, TPM4, VIME and TBB5 were correlated with the degree of genomic instability, established clinical risk factors and overall survival. Genomic instability was associated with a GS >= 7 (p = 0.001) and worse overall survival (p = 0.008). A positive SATB1 expression was associated with a GS = 7 were identified as markers for poor prognosis. Their combination overcomes current clinical risk stratification regimes.Functional Genomics of Muscle, Nerve and Brain Disorder

Defending the genome from the enemy within:mechanisms of retrotransposon suppression in the mouse germline

The viability of any species requires that the genome is kept stable as it is transmitted from generation to generation by the germ cells. One of the challenges to transgenerational genome stability is the potential mutagenic activity of transposable genetic elements, particularly retrotransposons. There are many different types of retrotransposon in mammalian genomes, and these target different points in germline development to amplify and integrate into new genomic locations. Germ cells, and their pluripotent developmental precursors, have evolved a variety of genome defence mechanisms that suppress retrotransposon activity and maintain genome stability across the generations. Here, we review recent advances in understanding how retrotransposon activity is suppressed in the mammalian germline, how genes involved in germline genome defence mechanisms are regulated, and the consequences of mutating these genome defence genes for the developing germline