Uncorrected Tetralogy of Fallot in a 25-Year Old Nigerian African

Tetralogy of Fallot is the most common form of cyanotic congenital heart disease. Survival after the age of 12 years without corrective surgery is rare. We present the case of a 25 year-old man with uncorrected tetralogy of Fallot. Possible reasons for the longetivity in this patient are left ventricular hypertrophy and systemic to pulmonary shunting through internal mammary arteries

Growth patterns in children after open heart surgery

Journal of the Singapore Paediatric Society15280-86SPSJ

Hospital mortality in a Singapore paediatric unit: a 10 year review

Journal of the Singapore Paediatric Society1619-22SPSJ

Enhanced oxygen reduction reaction catalyst stability and durability of MXene-supported Fe-N-C catalyst for proton exchange membrane fuel cell application

The wide application of proton exchange membrane fuel cells (PEMFCs) is hindered by their slow oxygen reduction reaction (ORR) at the cathode. To increase their practicality and economic viability, non-noble metal catalysts are developed to boost the cathodic reaction. However, they exhibit lower activity than noble metal catalysts and suffer from durability issues. In this study, multilayer Ti3C2Tx MXene is used as the catalyst support for a non-noble metal Fe-N-C catalyst for ORR. Fe-N-C is synthesized by doping Fe ions into a zeolitic imidazole framework (ZIF-8) precursor. MXene is introduced after the first pyrolysis with different mass ratios. A second pyrolysis heat treatment is employed to optimize the catalyst activity and stability. The optimized Fe-N-C/Ti3C2Tx-(4:1)− 500 composite catalyst demonstrates higher ORR activity (Eonset = 0.88 V vs. RHE) than Fe-N-C (Eonset = 0.83 V vs. RHE) catalyst. Its stability is better than commercial Pt/C for over 10,000 s based on a chronoamperometry test. More than 94% of the current remains after 10,000 s for the composite catalyst, while Pt/C only retains 61%. The durability investigation involving load cycle and start-stop cycle protocols further substantiates the durability of the Fe-N-C/Ti3C2Tx-(4:1)− 500 catalyst for ORR. In addition, the use of Ti3C2Tx MXene as the catalyst support for Fe-N-C improves PEMFC performance with an 80.8% increment in power density compared to that without MXene support

The E-Cadherin and N-Cadherin Switch in Epithelial-to-Mesenchymal Transition: Signaling, Therapeutic Implications, and Challenges

10.3390/cells8101118Cells81

Incorporating structural abnormalities in equivalent dipole layer based ECG simulations

Introduction: Electrical activity of the myocardium is recorded with the 12-lead ECG. ECG simulations can improve our understanding of the relation between abnormal ventricular activation in diseased myocardium and body surface potentials (BSP). However, in equivalent dipole layer (EDL)-based ECG simulations, the presence of diseased myocardium breaks the equivalence of the dipole layer. To simulate diseased myocardium, patches with altered electrophysiological characteristics were incorporated within the model. The relation between diseased myocardium and corresponding BSP was investigated in a simulation study. Methods: Activation sequences in normal and diseased myocardium were simulated and corresponding 64-lead BSP were computed in four models with distinct patch locations. QRS-complexes were compared using correlation coefficient (CC). The effect of different types of patch activation was assessed. Of one patient, simulated electrograms were compared to electrograms recorded during invasive electro-anatomical mapping. Results: Hundred-fifty-three abnormal activation sequences were simulated. Median QRS-CC of delayed versus dyssynchronous were significantly different (1.00 vs. 0.97, p < 0.001). Depending on the location of the patch, BSP leads were affected differently. Within diseased regions, fragmentation, low bipolar voltages and late potentials were observed in both recorded and simulated electrograms. Discussion: A novel method to simulate cardiomyopathy in EDL-based ECG simulations was established and evaluated. The new patch-based approach created a realistic relation between ECG waveforms and underlying activation sequences. Findings in the simulated cases were in agreement with clinical observations. With this method, our understanding of disease progression in cardiomyopathies may be further improved and used in advanced inverse ECG procedures

The National University of Singapore nuclear microscope facility

Nuclear Inst. and Methods in Physics Research, B851-4708-715NIMB

Nucleotide sequence alignment and compression via shortest unique substring

Aligning short reads produced by high throughput sequencing equipments onto a reference genome is the fundamental step of sequence analysis. Since the sequencing machinery generates massive volumes of data, it is becoming more and more vital to keep those data compressed also. In this study we present the initial results of an on-going research project, which aims to combine the alignment and compression of short reads with a novel preprocessing technique based on shortest unique substring identifiers. We observe that clustering the short reads according to the set of unique identifiers they include provide us an opportunity to combine compression and alignment. Thus, we propose an alternative path in high-throughput sequence analysis pipeline, where instead of applying an immediate whole alignment, a preprocessing that clusters the reads according to the set of shortest unique substring identifiers extracted from the reference genome is to be performed first. We also present an analysis of the short unique substrings identifiers on the human reference genome and examine how labeling each short read with those identifiers helps in alignment and compression

Changes in near-infrared spectroscopy after congenital cyanotic heart surgery

10.3389/fped.2018.00097Frontiers in Pediatrics69