An online fast multi-track locating algorithm for high-resolution single-event effect test platform

To improve the efficiency and accuracy of single-event effect(SEE)research at the Heavy Ion Research Facility at Lanzhou,Hi’Beam-SEE must precisely localize the position at which each heavy ion hitting the integrated circuit(IC)causes SEE.In this study,we propose a fast multi-track location(FML)method based on deep learning to locate the position of each particle track with high speed and accuracy.FML can process a vast amount of data supplied by Hi’Beam-SEE online,revealing sensitive areas in real time.FML is a slot-based object-centric encoder-decoder structure in which each slot can learn the location information of each track in the image.To make the method more accurate for real data,we designed an algorithm to generate a simulated dataset with a distribution similar to that of the real data,which was then used to train the model.Extensive comparison experiments demonstrated that the FML method,which has the best performance on simulated datasets,has high accuracy on real datasets as well.In particular,FML can reach 238 fps and a standard error of 1.6237μm.This study discusses the design and performance of FML.

Clinical characteristics and management of coexistent cardiomyopathy in patients with bicuspid aortic valve

BACKGROUND Bicuspid aortic valve(BAV)is the most common congenital heart disease.However,the prevalence,clinical characteristics,and current management of BAV associated with inherited cardiomyopathy,including hypertrophic cardiomy-opathy(HCM),dilated cardiomyopathy(DCM),and left ventricular noncompaction(LVNC)have not been well described.METHODS Consecutive patients diagnosed with BAV at a large tertiary cardiovascular referral center between 2009 and 2018 were retrospectively assessed for HCM,DCM,and LVNC based on clinical and echocardiographic criteria.Patients with coexist-ent conditions were investigated further.RESULTS Of 3533 patients with BAV screened,57(1.6%)had concomitant cardiomyopathy.BAV was combined with HCM in 30 of these patients,with DCM in 19,and with LVNC in eight.Forty-six patients(80.7%)were male,and the mean age at first dia-gnosis was 47 years for BAV with HCM,49 years for BAV with DCM,and 35 years for BAV with LVNC.Heart failure and aortic valve dysfunction were common in these patients,and the prevalence of coexisting aortopathy was 43.3%,26.3%and 25.0%,re-spectively,for BAV with HCM,DCM and LVNC.During the index hospitalization,24 of the 57 patients(42.1%)underwent sur-gery,16(28%)underwent aortic valve and/or aortic surgery,and 16 of the 30 patients with HCM had a Morrow procedure.There were no deaths or other major adverse cardiovascular events.CONCLUSIONS The prevalence of inherited cardiomyopathy was higher in our patients with BAV than in the general popula-tion.Aortopathy and heart failure were common,with almost half of patients requiring surgery at diagnosis.

Implication of a novel truncating mutation in titin as a cause of autosomal dominant left ventricular noncompaction

BACKGROUND Mutation in the titin gene(TTN)in left ventricular noncompaction(LVNC)has been reported with a highly heterogeneous prevalence,and the molecular mechanisms underlying the pathogenesis of TTN gene mutation are uncharacteri-zed.In the present study,we identified a novel TTN mutation in a pedigree with LVNC and investigated the potential pathogenic mechanism by functional studies.METHODS The whole-genome sequencing with linkage analysis was performed in a 3-generation family affected by autoso-mal dominant LVNC cardiomyopathy.The clustered regularly interspaced short palindromic repeats associated protein 9(CRISPR/Cas9)technology was used to establish novel truncating mutation in TTN in a rat cardiomyoblast H9C2 cell line in vitro,in which functional studies were carried out and characterized in comparison to its wild-type counterpart.RESULTS A novel truncating mutation TTN p.R2021X was identified as the only plausible disease-causing variant that segreg-ated with disease among the five surviving affected individuals,with an interrogation of the entire genome excluding other po-tential causes.Quantitative reverse transcription-polymerase chain reaction and cellular immunofluorescence supported a haplo-insufficient disease mechanism in titin truncation mutation cardiomyocytes.Further functional studies suggested mitochondrial abnormities in the presence of mutation,including decreased oxygen consumption rate,reduced adenosine triphosphate produc-tion,impaired activity of electron translation chain,and abnormal mitochondrial structure on electron microscopy.Impaired aut-ophagy under electron microscopy accompanied with activation of the Akt-mTORC1 signaling pathway was observed in TTN p.R2021X truncation mutation cardiomyocytes.CONCLUSIONS The TTN p.R2021X mutation has a function in the cause of a highly penetrant familial LVNC.These findings expand the spectrum of titin’s roles in cardiomyopathies and provide novel insight into the molecular basis of titin-truncating variants-associated LVNC.

A novel missense mutation in obscurin gene in a Chinese consanguineous family with left ventricular noncompaction

BACKGROUND Left ventricular noncompaction(LVNC) is an increasingly recognised cardiomyopathy of which a significant percentage are genetic in origin. The purpose of the present study was to identify potential pathogenic mutation leading to disease in a Chinese LVNC family.METHODS A 3-generation family affected by LVNC was recruited. Clinical assessments were performed on available family members, with clinical examination, ECG, echocardiography and cardiac MRI. The proband(Ⅰ-2), the proband’s daughter(Ⅱ-1, affected) and mother(Ⅲ-1, unaffected) were selected for WGS. Sanger sequencing were performed in all of the 4 surviving family members.RESULTS Combined whole genome sequencing with linkage analysis identified a novel missense mutation in the giant protein obscurin(OBSCN NM_001098623, c.C19063T), as the only plausible disease-causing variant that segregates with disease among the four surviving individuals, with interrogation of the entire genome excluding other potential causes. This c.C19063T missense mutation resulted in p.R6355W in the encoded OBSCN protein. It affected a highly conserved residue in the C terminus of the obscurin-B-like isoform between the PH and STKc domains, which was predicted to affect the function of the protein by different bioinformatics tools.CONCLUSIONS Here we present clinical and genetic evidence implicating the novel R6355W missense mutation in obscurin as the cause of familial LVNC. This expands the spectrum of obscurin’s roles in cardiomyopathies. It furthermore highlights that rare obscurin missense variants, currently often ignored or left uninterpreted, should be considered to be relevant for cardiomyopathies and can be identified by the approach presented here. This study also provided new insights into the molecular basis of OBSCN mutation positive LVNC.