Building crystalline topological superconductors from Shiba lattices

Localized or propagating Majorana boundary modes are the key feature of topological superconductors. While being a rarity in natural compounds, the tailored manipulation of quantum matter offers novel opportunities for their realization. Specifically, lattices of Shiba bound states that arise when magnetic adatoms are placed on the surface of a conventional superconductor can be used to create topological minibands within the superconducting gap of the substrate. Here, we exploit the possibilities of scanning tunneling microscopy to create and probe adatom lattices with single atom precision to create topological crystalline superconductors. Their topological character and boundary modes are protected by the spatial symmetries of the adatom lattice. We combine scanning probe spectroscopy, spin-sensitive measurements, first principle calculations, and theoretical modeling to to reveal signatures consistent with the realization of two types of mirror-symmetry protected topological superconductors: (i) with full bulk gap and topological edge as well as higher-order corner states and (ii) with symmetry-protected bulk nodal points. Our results show the immense versatility of Shiba lattices to design the topology and sample geometry of 2D superconductors.Comment: Published in Nature Physics (https://doi.org/10.1038/s41567-023-02104-5

A new diagnostic algorithm for Burkitt and diffuse large B-cell lymphomas based on the expression of CSE1L and STAT3 and on MYC rearrangement predicts outcome

Background Aggressive mature B-cell non-Hodgkin's lymphomas (BCL) sharing features of Burkitt's lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL) (intermediate BL/DLBCL) but deviating with respect to one or more characteristics are increasingly recognized. The limited knowledge about these biologically heterogeneous lymphomas hampers their assignment to a known entity, raising incertitude about optimal treatment approaches. We therefore searched for discriminative, prognostic, and predictive factors for their better characterization. Patients and methods We analyzed 242 cytogenetically defined aggressive mature BCL for differential protein expression. Marker selection was based on recent gene-expression profile studies. Predictive models for diagnosis were established and validated by a different set of lymphomas. Results CSE1L- and inhibitor of DNA binding-3 (ID3)-overexpression was associated with the diagnosis of BL and signal transduction and transcription-3 (STAT3) with DLBCL (P<0.001 for all markers). All three markers were associated with patient outcome in DLBCL. A new algorithm discriminating BL from DLBCL emerged, including the expression of CSE1L, STAT3, and MYC translocation. This ‘new classifier' enabled the identification of patients with intermediate BL/DLBCL who benefited from intensive chemotherapy regimens. Conclusion The proposed algorithm, which is based on markers with reliable staining properties for routine diagnostics, represents a novel valid tool in separating BL from DLBCL. Most interestingly, it allows segregating intermediate BL/DLBCL into groups with different treatment requirement

Prevalence, risk factors and outcomes of patients coming from the community with sepsis due to multidrug resistant bacteria

Background: Although previous studies showed an increasing prevalence of infections due to multi-drug resistant (MDR) bacteria in the community, specific data on sepsis are lacking. We aimed to assess prevalence, risk factors and outcomes of patients with sepsis due to MDR bacteria. Methods: An observational, retrospective study was conducted on consecutive adult patients coming from the community and admitted to the Policlinico Hospital, Milan, Italy, with a diagnosis of sepsis between January 2011 and December 2015. Primary study outcome was in-hospital mortality. Results: Among 518 patients, at least one MDR bacteria was isolated in 88 (17%). ESBL+ Enterobacteriaceae were the most prevalent MDR bacteria (9.7%) followed by MRSA (3.9%). Independent risk factors for sepsis due to MDR bacteria were septic shock (OR: 2.2; p = 0.002) and hospitalization in the previous 90 days (OR: 2.3; p = 0.003). Independent risk factors for sepsis due to ESBL+ bacteria were hospitalization in the previous 90 days (OR: 2.1; p = 0.02) and stroke (OR: 2.1; p = 0.04). A significantly higher mortality was detected among patients with vs. without MDR bacteria (40.2% vs. 23.1% respectively, p = 0.001). Independent risk factors for mortality among patients with sepsis were coagulation dysfunction (OR: 3.2; p = 0.03), septic shock (OR: 3.2; p = 0.003), and isolation of a MDR bacteria (OR: 4.6; p &lt; 0.001). Conclusion: In light of the prevalence and impact of MDR bacteria causing sepsis in patients coming from the community, physicians should consider ESBL coverage when starting an empiric antibiotic therapy in patients with specific risk factors, especially in the presence of septic shock

BIOF\u2013HILO assay: A new MALDI\u2013TOF mass spectrometry based method for discriminating between high-and low-biofilm-producing candida parapsilosis isolates

Candida parapsilosis is the most frequent cause of catheter-related candidemia among non-Candida albicans species. This may be related to intrinsic capabilities as adhering and forming a biofilm on abiotic surfaces such as on medical devices. As previously demonstrated, patients infected with high biofilm-producing C. parapsilosis isolates had a greater mortality risk compared to patients infected with low biofilm-producing C. parapsilosis isolates. We developed the BIOF\u2013HILO assay, a MALDI\u2013TOF mass spectrometry (MS)-based assay, which compares mass spectra obtained from attached and suspended isolate cells during the early (i.e., 3-h) adhesion phase of in vitro biofilm formation. The composite correlation index (CCI) analysis was used to discriminate between mass spectra differences of the two cell types, classifying all 50 C. parapsilosis clinical isolates, included in the study, after only 3-h of testing, in high or low biofilm producers. All high (n = 25) or low (n = 25) biofilm producers had, according to CCI mass spectra comparison values, higher or lower than one CCI ratios, which were obtained by dividing the CCIsuspendedcells by the CCIattachedcells . In conclusion, the BIOF\u2013HILO assay allows a rapid categorization of C. parapsilosis clinical isolates in high or low biofilm producers. This information, if timely provided to physicians, may improve treatment outcomes in patients with C. parapsilosis candidemia

Cross-sectional study of community serostatus to highlight undiagnosed HIV infections with oral fluid HIV-1/2 rapid test in non-conventional settings

The submerged portion of undiagnosed HIV infection in Italy is about 30% of subjects found seropositive. This fact represents one of the most important public health problems hindering the control of infection progression. This means we need to fight unawareness and social stigma and promote easy and friendly access to HIV test. We developed a Prevention Program called \u201cEASY test Project\u201d, offering a new rapid HIV test on oral fluid, to evaluate the acceptability of an alternative, free and anonymous test available in different settings (on board a \u201cMotor Home\u201d at public events, Points of Care, STDs outpatient prevention units and GP surgeries). From December 2008 to December 2012 we performed 7,865 HIV saliva tests, with 50 new infections found (0.6% of the total) out of 140,000 informed subjects. From the self-reported characteristics of respondents, the population approaching the EAST test project was represented by males (70%) aged between 20 and 50 years, 61% with a medium-high education level, 62% homosexuals (MSM), 88% reported unsafe sexual behaviours, and 48% had never undergone an HIV screening test. In five years of the Prevention Program, 100% of subjects interviewed gave a general favorable consent in approaching rapid and not invasive screening, immediate return of the result, and a timely specialized approach and treatment of HIV positive subjects. Results from our study confirm that the rapid and alternative test may contribute to HIV prevention strategies and to the control of the spread of infection and HIV disease progression by reaching a larger population, particularly when and where regular screening procedures are difficult to obtain or are not preferred

After DART: Using the First Full-scale Test of a Kinetic Impactor to Inform a Future Planetary Defense Mission

NASA’s Double Asteroid Redirection Test (DART) is the first full-scale test of an asteroid deflection technology. Results from the hypervelocity kinetic impact and Earth-based observations, coupled with LICIACube and the later Hera mission, will result in measurement of the momentum transfer efficiency accurate to ∼10% and characterization of the Didymos binary system. But DART is a single experiment; how could these results be used in a future planetary defense necessity involving a different asteroid? We examine what aspects of Dimorphos’s response to kinetic impact will be constrained by DART results; how these constraints will help refine knowledge of the physical properties of asteroidal materials and predictive power of impact simulations; what information about a potential Earth impactor could be acquired before a deflection effort; and how design of a deflection mission should be informed by this understanding. We generalize the momentum enhancement factor β, showing that a particular direction-specific β will be directly determined by the DART results, and that a related direction-specific β is a figure of merit for a kinetic impact mission. The DART β determination constrains the ejecta momentum vector, which, with hydrodynamic simulations, constrains the physical properties of Dimorphos’s near-surface. In a hypothetical planetary defense exigency, extrapolating these constraints to a newly discovered asteroid will require Earth-based observations and benefit from in situ reconnaissance. We show representative predictions for momentum transfer based on different levels of reconnaissance and discuss strategic targeting to optimize the deflection and reduce the risk of a counterproductive deflection in the wrong direction

Haemodynamic consequences of changing potassium concentrations in haemodialysis fluids

<p>Abstract</p> <p>Background</p> <p>A rapid decrease of serum potassium concentrations during haemodialysis produces a significant increase in blood pressure parameters at the end of the session, even if effects on intra-dialysis pressure are not seen. Paradoxically, in animal models potassium is a vasodilator and decreases myocardial contractility. The purpose of this trial is to study the precise haemodynamic consequences induced by acute changes in potassium concentration during haemodialysis.</p> <p>Methods</p> <p>In 24 patients, 288 dialysis sessions, using a randomised single blind crossover design, we compared six dialysate sequences with different potassium profiles. The dialysis sessions were divided into 3 tertiles, casually modulating potassium concentration in the dialysate between the value normally used K and the two cut-off points K+1 and K-1 mmol/l. Haemodynamics were evaluated in a non-invasive manner using a finger beat-to-beat monitor.</p> <p>Results</p> <p>Comparing K-1 and K+1, differences were found within the tertiles regarding systolic (+5.3, +6.6, +2.3 mmHg, p < 0.05, < 0.05, ns) and mean blood pressure (+4.3, +6.4, -0.5 mmHg, p < 0.01, < 0.01, ns), as well as peripheral resistance (+212, +253, -4 dyne.sec.cm^-5, p < 0.05, < 0.05, ns). The stroke volume showed a non-statistically-significant inverse trend (-3.1, -5.2, -0.2 ml). 18 hypotension episodes were recorded during the course of the study. 72% with K-1, 11% with K and 17% with K+1 (p < 0.01 for comparison K-1 vs. K and K-1 vs. K+1).</p> <p>Conclusions</p> <p>A rapid decrease in the concentration of serum potassium during the initial stage of the dialysis-obtained by reducing the concentration of potassium in the dialysate-translated into a decrease of systolic and mean blood pressure mediated by a decrease in peripheral resistance. The risk of intra-dialysis hypotension inversely correlates to the potassium concentration in the dialysate.</p> <p>Trial Registration Number</p> <p><a href="http://www.clinicaltrials.gov/ct2/show/NCT01224314">NCT01224314</a></p

An artificial impact on the asteroid (162173) Ryugu formed a crater in the gravity-dominated regime

The Hayabusa2 spacecraft investigated the small asteroid Ryugu, which has a rubble-pile structure. We describe an impact experiment on Ryugu using Hayabusa2’s Small Carry-on Impactor. The impact produced an artificial crater with a diameter >10 meters, which has a semicircular shape, an elevated rim, and a central pit. Images of the impact and resulting ejecta were recorded by the Deployable CAMera 3 for >8 minutes, showing the growth of an ejecta curtain (the outer edge of the ejecta) and deposition of ejecta onto the surface. The ejecta curtain was asymmetric and heterogeneous and it never fully detached from the surface. The crater formed in the gravity-dominated regime; in other words, crater growth was limited by gravity not surface strength. We discuss implications for Ryugu’s surface age

After DART: Using the First Full-scale Test of a Kinetic Impactor to Inform a Future Planetary Defense Mission

NASA’s Double Asteroid Redirection Test (DART) is the first full-scale test of an asteroid deflection technology. Results from the hypervelocity kinetic impact and Earth-based observations, coupled with LICIACube and the later Hera mission, will result in measurement of the momentum transfer efficiency accurate to ∼10% and characterization of the Didymos binary system. But DART is a single experiment; how could these results be used in a future planetary defense necessity involving a different asteroid? We examine what aspects of Dimorphos’s response to kinetic impact will be constrained by DART results; how these constraints will help refine knowledge of the physical properties of asteroidal materials and predictive power of impact simulations; what information about a potential Earth impactor could be acquired before a deflection effort; and how design of a deflection mission should be informed by this understanding. We generalize the momentum enhancement factor β, showing that a particular direction-specific β will be directly determined by the DART results, and that a related direction-specific β is a figure of merit for a kinetic impact mission. The DART β determination constrains the ejecta momentum vector, which, with hydrodynamic simulations, constrains the physical properties of Dimorphos’s near-surface. In a hypothetical planetary defense exigency, extrapolating these constraints to a newly discovered asteroid will require Earth-based observations and benefit from in situ reconnaissance. We show representative predictions for momentum transfer based on different levels of reconnaissance and discuss strategic targeting to optimize the deflection and reduce the risk of a counterproductive deflection in the wrong direction

Double Asteroid Redirection Test (DART): Structural and Dynamic Interactions between Asteroidal Elements of Binary Asteroid (65803) Didymos

Abstract NASA's Double Asteroid Redirection Test (DART) mission is the first full-scale planetary defense mission. The target is the binary asteroid (65803) Didymos, in which the smaller component Dimorphos (∼164 m equivalent diameter) orbits the larger component Didymos (∼780 m equivalent diameter). The DART spacecraft will impact Dimorphos, changing the system’s mutual orbit by an amount that correlates with DART's kinetic deflection capability. The spacecraft collision with Dimorphos creates an impact crater, which reshapes the body. Also, some particles ejected from the DART impact site on Dimorphos eventually reach Didymos. Because Didymos’s rapid spin period (2.26 hr) may be close to its stability limit for structural failure, the ejecta reaching Didymos may induce surface disturbance on Didymos. While large uncertainties exist, nonnegligible reshaping scenarios on Didymos and Dimorphos are possible if certain conditions are met. Our analysis shows that given a surface slope uncertainty on Dimorphos of 45°, with no other information about its local topography, and if the DART-like impactor is treated as spherical, the ejecta cone crosses Didymos with speeds ≳14 m s−1 in 13% of simulations. Additional work is necessary to determine the amount of mass delivered to Didymos from the DART impact and whether the amount of kinetic energy delivered is sufficient to overcome cohesive forces in those cases. If nonnegligible (but small) reshaping occurs for either of these asteroids, the resulting orbit perturbation and reshaping are measurable by Earth-based observations.</jats:p