Observation of vanishing charge dispersion of a nearly-open superconducting island

Isolation from the environment determines the extent to which charge is confined on an island, which manifests as Coulomb oscillations such as charge dispersion. We investigate the charge dispersion of a nanowire transmon hosting a quantum dot in the junction. We observe rapid suppression of the charge dispersion with increasing junction transparency, consistent with the predicted scaling law which incorporates two branches of the Josephson potential. We find improved qubit coherence times at the point of highest suppression, suggesting novel approaches for building charge-insensitive qubits

A gate-tunable, field-compatible fluxonium

Circuit quantum electrodynamics, where photons are coherently coupled to artificial atoms built with superconducting circuits, has enabled the investigation and control of macroscopic quantum-mechanical phenomena in superconductors. Recently, hybrid circuits incorporating semiconducting nanowires and other electrostatically-gateable elements have provided new insights into mesoscopic superconductivity. Extending the capabilities of hybrid flux-based circuits to work in magnetic fields would be especially useful both as a probe of spin-polarized Andreev bound states and as a possible platform for topological qubits. The fluxonium is particularly suitable as a readout circuit for topological qubits due to its unique persistent-current based eigenstates. In this Letter, we present a magnetic-field compatible hybrid fluxonium with an electrostatically-tuned semiconducting nanowire as its non-linear element. We operate the fluxonium in magnetic fields up to 1T and use it to observe the $\varphi_0$-Josephson effect. This combination of gate-tunability and field-compatibility opens avenues for the exploration and control of spin-polarized phenomena using superconducting circuits and enables the use of the fluxonium as a readout device for topological qubits

Ballistic InSb Nanowires and Networks via Metal-Sown Selective Area Growth

Selective area growth is a promising technique to realize semiconductor-superconductor hybrid nanowire networks, potentially hosting topologically protected Majorana-based qubits. In some cases, however, such as the molecular beam epitaxy of InSb on InP or GaAs substrates, nucleation and selective growth conditions do not necessarily overlap. To overcome this challenge, we propose a metal-sown selective area growth (MS SAG) technique, which allows decoupling selective deposition and nucleation growth conditions by temporarily isolating these stages. It consists of three steps: (i) selective deposition of In droplets only inside the mask openings at relatively high temperatures favoring selectivity, (ii) nucleation of InSb under Sb flux from In droplets, which act as a reservoir of group III adatoms, done at relatively low temperatures, favoring nucleation of InSb, and (iii) homoepitaxy of InSb on top of the formed nucleation layer under a simultaneous supply of In and Sb fluxes at conditions favoring selectivity and high crystal quality. We demonstrate that complex InSb nanowire networks of high crystal and electrical quality can be achieved this way. We extract mobility values of 10※000-25※000 cm V s consistently from field-effect and Hall mobility measurements across single nanowire segments as well as wires with junctions. Moreover, we demonstrate ballistic transport in a 440 nm long channel in a single nanowire under a magnetic field below 1 T. We also extract a phase-coherent length of ∼8 μm at 50 mK in mesoscopic rings

Twist exome capture allows for lower average sequence coverage in clinical exome sequencing

Background Exome and genome sequencing are the predominant techniques in the diagnosis and research of genetic disorders. Sufficient, uniform and reproducible/consistent sequence coverage is a main determinant for the sensitivity to detect single-nucleotide (SNVs) and copy number variants (CNVs). Here we compared the ability to obtain comprehensive exome coverage for recent exome capture kits and genome sequencing techniques. Results We compared three different widely used enrichment kits (Agilent SureSelect Human All Exon V5, Agilent SureSelect Human All Exon V7 and Twist Bioscience) as well as short-read and long-read WGS. We show that the Twist exome capture significantly improves complete coverage and coverage uniformity across coding regions compared to other exome capture kits. Twist performance is comparable to that of both short- and long-read whole genome sequencing. Additionally, we show that even at a reduced average coverage of 70× there is only minimal loss in sensitivity for SNV and CNV detection. Conclusion We conclude that exome sequencing with Twist represents a significant improvement and could be performed at lower sequence coverage compared to other exome capture techniques

A Solve-RD ClinVar-based reanalysis of 1522 index cases from ERN-ITHACA reveals common pitfalls and misinterpretations in exome sequencing

Purpose Within the Solve-RD project (https://solve-rd.eu/), the European Reference Network for Intellectual disability, TeleHealth, Autism and Congenital Anomalies aimed to investigate whether a reanalysis of exomes from unsolved cases based on ClinVar annotations could establish additional diagnoses. We present the results of the “ClinVar low-hanging fruit” reanalysis, reasons for the failure of previous analyses, and lessons learned. Methods Data from the first 3576 exomes (1522 probands and 2054 relatives) collected from European Reference Network for Intellectual disability, TeleHealth, Autism and Congenital Anomalies was reanalyzed by the Solve-RD consortium by evaluating for the presence of single-nucleotide variant, and small insertions and deletions already reported as (likely) pathogenic in ClinVar. Variants were filtered according to frequency, genotype, and mode of inheritance and reinterpreted. Results We identified causal variants in 59 cases (3.9%), 50 of them also raised by other approaches and 9 leading to new diagnoses, highlighting interpretation challenges: variants in genes not known to be involved in human disease at the time of the first analysis, misleading genotypes, or variants undetected by local pipelines (variants in off-target regions, low quality filters, low allelic balance, or high frequency). Conclusion The “ClinVar low-hanging fruit” analysis represents an effective, fast, and easy approach to recover causal variants from exome sequencing data, herewith contributing to the reduction of the diagnostic deadlock

Systematic Review and Meta-Analysis of Extraperitoneal Versus Transperitoneal Colostomy for Preventing Parastomal Hernia

BACKGROUND: Parastomal hernia remains a frequent problem after constructing a colostomy. Current research mainly focuses on prophylactic mesh placement as an addition to transperitoneal colostomies. However, for constructing a colostomy, either an extraperitoneal or transperitoneal route can be chosen. OBJECTIVE: The aim of this meta-analysis was to investigate which technique results in lower parastomal hernia rates in patients undergoing end colostomy. DATA SOURCES: A meta-analysis was conducted according to Preferred Items for Reporting of Systematic Reviews and Meta-Analyses and Meta-Analysis of Observational Studies in Epidemiology guidelines. Embase, MEDLINE, Web of Science, Scopus, Cumulative Index to Nursing and Allied Health Literature, Cochrane, PubMed, and Google Scholar databases were searched. The study protocol was registered in the International Prospective Register of Systematic Reviews database. STUDY SELECTION: Studies comparing extraperitoneal and transperitoneal colostomies were included. Only studies written in English were included. The quality of studies and risk of bias were assessed using the Cochrane risk-of-bias tool. The quality of nonrandomized studies was assessed using the Newcastle-Ottawa Scale. INTERVENTION: The intervention was colostomy formation. MAIN OUTCOME MEASURES: The main outcome measure was parastomal hernia incidence. Secondary outcome measures were stoma prolapse, stoma necrosis, and operating time. RESULTS: Of 401 articles found, a meta-analysis was conducted of 10 studies (2 randomized controlled trials and 8 retrospective studies) composed of 1048 patients (347 extraperitoneal and 701 transperitoneal). Extraperitoneal colostomy led to significantly lower parastomal hernia rates (22 of 347 (6.3%) for extraperitoneal versus 125 of 701 (17.8%) for transperitoneal; risk ratio = 0.36 (95% CI, 0.21-0.62); I-2 = 26%; p < 0.001) and significantly lower stoma prolapse rates (2 of 185 (1.1%) for extraperitoneal versus 13 of 179 (7.3%) for transperitoneal; risk ratio = 0.21 (95% CI, 0.06-0.73); I-2 = 0%; p = 0.01). Differences in stoma necrosis were not significant. Operating time data were insufficient to analyze. LIMITATIONS: Most of the studies were nonrandomized, and some were not recent publications. CONCLUSIONS: Although the majority of studies included were retrospective, extraperitoneal colostomy was observed to lead to a lower rate of parastomal hernia and stoma prolapse