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Applications of quantum walks can depend on the number, exchange symmetry and indistinguishability of the particles involved, and the underlying graph structures where they move. Here, we show that silicon photonics, by exploiting an entanglement-driven scheme, can realize quantum walks with full control over all these properties in one device. The device we realize implements entangled two-photon quantum walks on any five-vertex graph, with continuously tunable particle exchange symmetry and indistinguishability. We show how this simulates single-particle walks on larger graphs, with size and geometry controlled by tuning the properties of the composite quantum walkers. We apply the device to quantum walk algorithms for searching vertices in graphs and testing for graph isomorphisms. In doing so, we implement up to 100 sampled time steps of quantum walk evolution on each of 292 different graphs. This opens the way to large-scale, programmable quantum walk processors for classically intractable applications.Bioactive metabolites have wide-ranging biological activities and are a potential source of future research and therapeutic tools. Here, we use nanovibrational stimulation to induce osteogenic differentiation of mesenchymal stem cells, in the absence of off-target, nonosteogenic differentiation. We show that this differentiation method, which does not rely on the addition of exogenous growth factors to culture media, provides an artifact-free approach to identifying bioactive metabolites that specifically and potently induce osteogenesis. We first identify a highly specific metabolite, cholesterol sulfate, an endogenous steroid. Next, a screen of other small molecules with a similar steroid scaffold identified fludrocortisone acetate with both specific and highly potent osteogenic-inducing activity. Further, we implicate cytoskeletal contractility as a measure of osteogenic potency and cell stiffness as a measure of specificity. These findings demonstrate that physical principles can be used to identify bioactive metabolites and then enable optimization of metabolite potency can be optimized by examining structure-function relationships.Understanding variation in the sulfur isotopic composition of sedimentary pyrite (δ34Spyr) is motivated by the key role of sulfur biogeochemistry in regulating Earth’s surface oxidation state. Until recently, the impact of local depositional conditions on δ34Spyr has remained underappreciated, and stratigraphic variations in δ34Spyr were interpreted mostly to reflect global changes in biogeochemical cycling. We present two coeval δ34Spyr records from shelf and basin settings in a single sedimentary system. Despite their proximity and contemporaneous deposition, these two records preserve radically different geochemical signals. Swings of ~65‰ in shelf δ34Spyr track short-term variations in local sedimentation and are completely absent from the abyssal record. In contrast, a long-term ~30‰ decrease in abyssal δ34Spyr reflects regional changes in ocean circulation and/or sustained pyrite formation. These results highlight strong local controls on δ34Spyr, calling for reevaluation of the current practice of using δ34Spyr stratigraphic variations to infer global changes in Earth’s surface environment.

The humoral response against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the hemodialysis population, including its dynamics over time, remains poorly understood.

To analyze initial and long-term humoral responses against SARS-CoV-2 in a hemodialysis population, we retrospectively evaluated findings from SARS-CoV-2 IgG serologic assays targeting the nucleocapsid antigen or spike antigen up to 6 months of follow-up in patients on hemodialysis in the Paris, France, region who had recovered from coronavirus disease 2019 (COVID-19).

Our analysis included 83 patients (median age 65 years); 59 (71%) were male and 28 (34%) had presented with severe COVID-19. We observed positive initial SARS-CoV-2 IgG antinucleocapsid serology in 74 patients (89%) at a median of 67 days postdiagnosis. By multivariable analysis, immunocompromised status was the only factor significantly associated with lack of an IgG antinucleocapsid antibody response. Follow-up data were available at 6 months postdiagnosis lack of seroconversion and with IgG titer decay.A severe case of COVID-19 was observed in an otherwise healthy 28-year-old man who had taken oxandrolone 40 mg/day as an anabolic steroid. The patient had been taking oxandrolone for enhanced bodybuilding 30 days prior to presenting to an outpatient clinic with COVID-19 symptoms. The patient reported that his symptoms have rapidly worsened over the course of 4 days prior to presenting at the clinic. As part of an experimental antiandrogen treatment for hyperandrogenic men suffering from COVID-19, he was administered a single 600 mg dose of the novel antiandrogen proxalutamide. Twenty-four hours after administration of this dose, marked improvement of symptoms and markers of disease severity were observed. To our knowledge, this is the first case that potentially links anabolic steroid use to COVID-19 disease severity.Arterial thoracic outlet syndrome is relatively rare and often exclusively seen in the presence of bony anomalies. High-altitude (HA) travel is commonly associated with thrombosis; however, arterial thromboembolism is less frequently described. We describe a case of a young man with undiagnosed bilateral cervical rib, who went for an HA trek, subsequent to which developed acute limb ischaemia of right arm. Diagnostic workup revealed a subclavian artery aneurysm as well along with complete bony bilateral cervical ribs. Selleck Blasticidin S Thoracic outlet syndrome should be kept as a differential diagnosis in a case of acute limb ischaemia in a healthy adult.We present an unusual ischial fracture unreported in the literature. We discuss the mechanism and describe the appropriate investigations and surgical management of this fracture. A 36-year-old man sustained a direct blow to his right buttock following a fall from a dirt bike. Examination revealed a firm haematoma, with severe pain on any stretch involving the posterior compartment of the thigh. Radiographs revealed a displaced fracture of the ischial body. CT confirmed integrity of the pelvic ring. The patient underwent open reduction and internal fixation with a partially threaded cannulated screw via a ‘modified longitudinal’ posterior approach to the ischium. The patient was managed partially weight-bearing for 6 weeks; 6-month follow-up confirmed satisfactory clinical and radiographic outcomes. Clinicians should be aware of this novel pelvic fracture and its unusual presentation, currently not included in any pelvic fracture classification system. We report a novel operative technique for appropriate surgical management of such injuries.