Metropolitan quantum key distribution with silicon photonics

Photonic integrated circuits (PICs) provide a compact and stable platform for quantum photonics. Here we demonstrate a silicon photonics quantum key distribution (QKD) transmitter in the first high-speed polarization-based QKD field tests. The systems reach composable secret key rates of 950 kbps in a local test (on a 103.6-m fiber with a total emulated loss of 9.2 dB) and 106 kbps in an intercity metropolitan test (on a 43-km fiber with 16.4 dB loss). Our results represent the highest secret key generation rate for polarization-based QKD experiments at a standard telecom wavelength and demonstrate PICs as a promising, scalable resource for future formation of metropolitan quantum-secure communications networks

Recovery of end-organs and improved mortality in adult patient on ECMO.

Title: Recovery of End-Organs and Improved Mortality in Adult Patients on ECMO Joshua K Wong, BS1, Vei Shaun Siow, BS1, Thomas N Smith, BS1, Harrison Pitcher, MD2, Linda Bogar, MD2, Hitoshi Hirose, MD2 and Nicholas C Cavarocchi, MD2. 1Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States, 19107 and 2Division of Cardiothoracic Surgery, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, United States, 19107. Body: With increasing use of ECMO in adults, we seek to objectively measure End-Organ recovery and correlate intensive care mortality scores and complications with patient survival. This is a retrospective review of patients who were placed on ECMO from Oct 2010 to Dec 2011. End-Organ function was measured through Pa02/Fi02 ratios, lactate levels, MELD and mortality scores (SAPSII/APACHEII/SOFA). Complications were recorded and analyzed. Twenty-three patients were placed on VA-ECMO and 5 on VV-ECMO. 22 (73%) patients were successfully weaned off ECMO, and 13 (46%) survived to discharge. In 12 patients with liver injury pre-ECMO, the median MELD score was 21 vs 13 post-ECMO (

Comparative Survival and Economic Benefits of Deceased Donor Kidney Transplantation and Dialysis in People with Varying Ages and Co-Morbidities

<div><h3>Background</h3><p>Deceased donor kidneys for transplantation are in most countries allocated preferentially to recipients who have limited co-morbidities. Little is known about the incremental health and economic gain from transplanting those with co-morbidities compared to remaining on dialysis. The aim of our study is to estimate the average and incremental survival benefits and health care costs of listing and transplantation compared to dialysis among individuals with varying co-morbidities.</p> <h3>Methods</h3><p>A probabilistic Markov model was constructed, using current outcomes for patients with defined co-morbidities treated with either dialysis or transplantation, to compare the health and economic benefits of listing and transplantation with dialysis.</p> <h3>Findings</h3><p>Using the current waiting time for deceased donor transplantation, transplanting a potential recipient, with or without co-morbidities achieves survival gains of between 6 months and more than three life years compared to remaining on dialysis, with an average incremental cost-effectiveness ratio (ICER) of less than $50,000/LYS, even among those with advanced age. Age at listing and the waiting time for transplantation are the most influential variables within the model. If there were an unlimited supply of organs and no waiting time, transplanting the younger and healthier individuals saves the most number of life years and is cost-saving, whereas transplanting the middle-age to older patients still achieves substantial incremental gains in life expectancy compared to being on dialysis.</p> <h3>Conclusions</h3><p>Our modelled analyses suggest transplanting the younger and healthier individuals with end-stage kidney disease maximises survival gains and saves money. Listing and transplanting those with considerable co-morbidities is also cost-effective and achieves substantial survival gains compared with the dialysis alternative. Preferentially excluding the older and sicker individuals cannot be justified on utilitarian grounds.</p> </div

Low-coverage whole-genome sequencing of extracellular vesicle-associated DNA in patients with metastatic cancer

© 2021, The Author(s). Low-coverage whole-genome sequencing (LC-WGS) can provide insight into oncogenic molecular changes. Serum extracellular vesicles (EV) represent a novel liquid biopsy source of tumoral DNA. This study compared copy number alteration (CNA) profiles generated from LC-WGS of formalin-fixed paraffin-embedded (FFPE) tumoral DNA and EV-DNA obtained from cancer patients. Patients with squamous cell carcinoma of the base of tongue (n = 3) and cutaneous squamous cell carcinoma (n = 2) were included. LC-WGS (0.5-1X coverage) was performed on FFPE-DNA and serum EV-DNA. Similarity between CNA profiles was analysed using QDNAseq. FFPE samples had a mean CNA of 31 (range 17–50) over 1.9 × 109 (range 1.0–2.6 × 109) bp in length, and EV samples had a mean CNA value of 17 (range 7–19) over 7.6 × 108 (range 2.9–15 × 108) bp in length. A mean of 8 (range 0–21) CNA over 5.9 × 108 (range 1.6–14 × 108) bp in length was found to overlap between EV and FFPE-derived samples per patient. Although the mean correlation efficient between samples was r = 0.34 (range − .08 to 0.99), this was not statistically significant (p \u3e 0.05). Regions of highest deletion and duplication in FFPE samples were not well reflected in the EV-DNA. Selected CNA regions in EV-associated DNA were reflective of the primary tumor, however appreciation of global CNA and areas of most significant change was lost. The utility of LC-WGS of EV-derived DNA is likely limited to molecular alterations of known interest

Evaluation of microRNA expression in patient bone marrow aspirate slides

<div><p>Like formalin fixed paraffin embedded (FFPE) tissues, archived bone marrow aspirate slides are an abundant and untapped resource of biospecimens that could enable retrospective molecular studies of disease. Historically, RNA obtained from slides is limited in utility because of their low quality and highly fragmented nature. MicroRNAs are small (≈22 nt) non-coding RNA that regulate gene expression, and are speculated to preserve well in FFPE tissue. Here we investigate the use of archived bone marrow aspirate slides for miRNA expression analysis in paediatric leukaemia. After determining the optimal method of miRNA extraction, we used TaqMan qRT-PCR to identify reference miRNA for normalisation of other miRNA species. We found hsa-miR-16 and hsa-miR-26b to be the most stably expressed between lymphoblastoid cell lines, primary bone marrow aspirates and archived samples. We found the average fold change in expression of hsa-miR-26b and two miRNA reportedly dysregulated in leukaemia (hsa-miR-128a, hsa-miR-223) was <0.5 between matching archived slide and bone marrow aspirates. Differential expression of hsa-miR-128a and hsa-miR-223 was observed between leukaemic and non-leukaemic bone marrow from archived slides or flash frozen bone marrow. The demonstration that archived bone marrow aspirate slides can be utilized for miRNA expression studies offers tremendous potential for future investigations into the role miRNA play in the development and long term outcome of hematologic, as well as non-hematologic, diseases.</p> </div

Methylomic trajectories across human fetal brain development

Open access articleEpigenetic processes play a key role in orchestrating transcriptional regulation during development. The importance of DNA methylation in fetal brain development is highlighted by the dynamic expression of de novo DNA methyltransferases during the perinatal period and neurodevelopmental deficits associated with mutations in the methyl-CpG binding protein 2 (MECP2) gene. However, our knowledge about the temporal changes to the epigenome during fetal brain development has, to date, been limited. We quantified genome-wide patterns of DNA methylation at ∼ 400,000 sites in 179 human fetal brain samples (100 male, 79 female) spanning 23 to 184 d post-conception. We identified highly significant changes in DNA methylation across fetal brain development at >7% of sites, with an enrichment of loci becoming hypomethylated with fetal age. Sites associated with developmental changes in DNA methylation during fetal brain development were significantly underrepresented in promoter regulatory regions but significantly overrepresented in regions flanking CpG islands (shores and shelves) and gene bodies. Highly significant differences in DNA methylation were observed between males and females at a number of autosomal sites, with a small number of regions showing sex-specific DNA methylation trajectories across brain development. Weighted gene comethylation network analysis (WGCNA) revealed discrete modules of comethylated loci associated with fetal age that are significantly enriched for genes involved in neurodevelopmental processes. This is, to our knowledge, the most extensive study of DNA methylation across human fetal brain development to date, confirming the prenatal period as a time of considerable epigenomic plasticity.MRCUniversity of Exeter Medical SchoolWellcome Trus

Permissive Transcriptional Activity at the Centromere through Pockets of DNA Hypomethylation

DNA methylation is a hallmark of transcriptional silencing, yet transcription has been reported at the centromere. To address this apparent paradox, we employed a fully sequence-defined ectopic human centromere (or neocentromere) to investigate the relationship between DNA methylation and transcription. We used sodium bisulfite PCR and sequencing to determine the methylation status of 2,041 CpG dinucleotides distributed across a 6.76-Mbp chromosomal region containing a neocentromere. These CpG dinucleotides were associated with conventional and nonconventional CpG islands. We found an overall hypermethylation of the neocentric DNA at nonconventional CpG islands that we designated as CpG islets and CpG orphans. The observed hypermethylation was consistent with the presence of a presumed transcriptionally silent chromatin state at the neocentromere. Within this neocentric chromatin, specific sites of active transcription and the centromeric chromatin boundary are defined by DNA hypomethylation. Our data demonstrate, for the first time to our knowledge, a correlation between DNA methylation and centromere formation in mammals, and that transcription and “chromatin-boundary activity” are permissible at the centromere through the selective hypomethylation of pockets of sequences without compromising the overall silent chromatin state and function of the centromere