Spin-triplet superconductivity in repulsive Hubbard models with disconnected Fermi surfaces: a case study on triangular and honeycomb lattices

We propose that spin-fluctuation-mediated spin-triplet superconductivity may be realized in repulsive Hubbard models with disconnected Fermi surfaces. The idea is confirmed for Hubbard models on triangular (dilute band filling) and honeycomb (near half-filling) lattices using fluctuation exchange approximation, where triplet pairing order parameter with f-wave symmetry is obtained. Possible relevance to real superconductors is suggested.Comment: 5 pages, 6 figures, RevTeX, uses epsf.sty and multicol.st

Is a chest radiograph indicated after chest tube removal in trauma patients? A systematic review

PURPOSE The aim of this systematic review was to assess the necessity of routine chest radiographs after chest tube removal in ventilated and nonventilated trauma patients. METHODS A systematic literature search was conducted in MEDLINE, Embase, CENTRAL, and CINAHL on May 15, 2020. Quality assessment was performed using the Methodological Index for Nonrandomized Studies criteria. Primary outcome measures were abnormalities on postremoval chest radiograph (e.g., recurrence of a pneumothorax, hemothorax, pleural effusion) and reintervention after chest tube removal. Secondary outcome measures were emergence of new clinical symptoms or vital signs after chest tube removal. RESULTS Fourteen studies were included, consisting of seven studies on nonventilated patients and seven studies on combined cohorts of ventilated and nonventilated patients, all together containing 1,855 patients. Nonventilated patients had abnormalities on postremoval chest radiograph in 10% (range across studies, 0-38%) of all chest tubes and 24% (range, 0-78%) of those underwent reintervention. In the studies that reported on clinical symptoms after chest tube removal, all patients who underwent reintervention also had symptoms of recurrent pathology. Combined cohorts of ventilated and nonventilated patients had abnormalities on postremoval chest radiograph in 20% (range, 6-49%) of all chest tubes and 45% (range, 8-63%) of those underwent reintervention. CONCLUSION In nonventilated patients, one in ten developed recurrent pathology after chest tube removal and almost a quarter of them underwent reintervention. In two studies that reported on clinical symptoms, all reinterventions were performed in patients with symptoms of recurrent pathology. In these two studies, omission of routine postremoval chest radiograph seemed safe. However, current literature remains insufficient to draw definitive conclusions on this matter, and future studies are needed. LEVEL OF EVIDENCE Systematic review study, level IV

Muon spin relaxation studies of incommensurate magnetism and superconductivity in stage-4 La2_{2}CuO4.11_{4.11} and La1.88_{1.88}Sr0.12_{0.12}CuO4_{4}

This paper reports muon spin relaxation (MuSR) measurements of two single crystals of the title high-Tc cuprate systems where static incommensurate magnetism and superconductivity coexist. By zero-field MuSR measurements and subsequent analyses with simulations, we show that (1) the maximum ordered Cu moment size (0.36 Bohr magneton) and local spin structure are identical to those in prototypical stripe spin systems with the 1/8 hole concentration; (2) the static magnetism is confined to less than a half of the volume of the sample, and (3) regions with static magnetism form nano-scale islands with the size comparable to the in-plane superconducting coherence length. By transverse-field MuSR measurements, we show that Tc of these systems is related to the superfluid density, in the same way as observed in cuprate systems without static magnetism. We discuss a heuristic model involving percolation of these nanoscale islands with static magnetism as a possible picture to reconcile heterogeneity found by the present MuSR study and long-range spin correlations found by neutron scattering.Comment: 19 pages, 15 figures, submitted to Phys. Rev. B. E-mail: [email protected]

Global changes in mortality rates in polytrauma patients admitted to the ICU - A systematic review

Background: Many factors of trauma care have changed in the last decades. This review investigated the effect of these changes on global all-cause and cause-specific mortality in polytrauma patients admitted to the intensive care unit (ICU). Moreover, changes in trauma mechanism over time and differences between continents were analyzed. Main body: A systematic review of literature on all-cause mortality in polytrauma patients admitted to ICU was conducted. All-cause and cause-specific mortality rates were extracted as well as trauma mechanism of each patient. Poisson regression analysis was used to model time trends in all-cause and cause-specific mortality. Thirty studies, which reported mortality rates for 82,272 patients, were included and showed a decrease of 1.8% (95% CI 1.6-2.0%) in all-cause mortality per year since 1966. The relative contribution of brain injury-related death has increased over the years, whereas the relative contribution of death due to multiple organ dysfunction syndrome (MODS), acute respiratory distress syndrome, and sepsis decreased. MODS was the most common cause of death in North America, and brain-related death was the most common in Asia, South America, and Europe. Penetrating trauma was most often reported in North America and Asia. Conclusions: All-cause mortality in polytrauma patients admitted to the ICU has decreased over the last decades. A shift from MODS to brain-related death was observed. Geographical differences in cause-specific mortality were present, which may provide region-specific learning possibilities resulting in improvement of global trauma care

Study methodology in trauma care: towards question-based study designs

The randomized controlled trial (RCT) in surgery may not always be ethical, feasible, or necessary to address a particular research question about the effect of a surgical intervention. If so, properly designed and conducted observational (non-randomized) studies may be valuable alternatives for an RCT and produce credible results. In this paper, we discus differences between RCTs and observational studies and differentiate between three types of comparisons of surgical interventions. We assert that results of different designs should be regarded as complementary to each other when evaluating surgical interventions. Criteria for credible observational research are presented to provide guidance for future observational research of surgical interventions. We argue that the research question that is being asked should guide the discussion about the value of a particular study design

The association of radiologic body composition parameters with clinical outcomes in level-1 trauma patients

Purpose: The present study aims to assess whether CT-derived muscle mass, muscle density, and visceral fat mass are associated with in-hospital complications and clinical outcome in level-1 trauma patients. Methods: A retrospective cohort study was conducted on adult patients admitted to the University Medical Center Utrecht following a trauma between January 1 and December 31, 2017. Trauma patients aged 16 years or older without severe neurological injuries, who underwent a CT that included the abdomen within 7 days of admission, were included. An artificial intelligence (AI) algorithm was used to retrieve muscle areas to calculate the psoas muscle index and to retrieve psoas muscle radiation attenuation and visceral fat (VF) area from axial CT images. Multivariable logistic and linear regression analyses were performed to assess associations between body composition parameters and outcomes. Results: A total of 404 patients were included for analysis. The median age was 49 years (interquartile range [IQR] 30–64), and 66.6% were male. Severe comorbidities (ASA 3–4) were seen in 10.9%, and the median ISS was 9 (IQR 5–14). Psoas muscle index was not independently associated with complications, but it was associated with ICU admission (odds ratio [OR] 0.79, 95% confidence interval [CI] 0.65–0.95), and an unfavorable Glasgow Outcome Scale (GOS) score at discharge (OR 0.62, 95% CI 0.45–0.85). Psoas muscle radiation attenuation was independently associated with the development of any complication (OR 0.60, 95% CI 0.42–0.85), pneumonia (OR 0.63, 95% CI 0.41–0.96), and delirium (OR 0.49, 95% CI 0.28–0.87). VF was associated with developing a delirium (OR 1.95, 95% CI 1.12–3.41). Conclusion: In level-1 trauma patients without severe neurological injuries, automatically derived body composition parameters are able to independently predict an increased risk of specific complications and other poor outcomes

Energy Flow in the Hadronic Final State of Diffractive and Non-Diffractive Deep-Inelastic Scattering at HERA

An investigation of the hadronic final state in diffractive and non--diffractive deep--inelastic electron--proton scattering at HERA is presented, where diffractive data are selected experimentally by demanding a large gap in pseudo --rapidity around the proton remnant direction. The transverse energy flow in the hadronic final state is evaluated using a set of estimators which quantify topological properties. Using available Monte Carlo QCD calculations, it is demonstrated that the final state in diffractive DIS exhibits the features expected if the interaction is interpreted as the scattering of an electron off a current quark with associated effects of perturbative QCD. A model in which deep--inelastic diffraction is taken to be the exchange of a pomeron with partonic structure is found to reproduce the measurements well. Models for deep--inelastic $ep$ scattering, in which a sizeable diffractive contribution is present because of non--perturbative effects in the production of the hadronic final state, reproduce the general tendencies of the data but in all give a worse description.Comment: 22 pages, latex, 6 Figures appended as uuencoded fil

Fermionic NNLL corrections to b -> s \gamma

In this paper we take the first step towards a complete next-to-next-to-leading logarithmic (NNLL) calculation of the inclusive decay rate for $B \to X_s\gamma$. We consider the virtual corrections of order \alphas^2 n_f to the matrix elements of the operators ${O}_1$, ${O}_2$ and ${O}_8$ and evaluate the real and virtual contributions to ${O}_7$. These corrections are expected to be numerically important. We observe a strong cancelation between the contributions from the current-current operators and $O_7$ and obtain, after applying naive non-abelianization, a reduction of the branching ratio of 3.9% (for $\mu=3.0$ GeV) and an increase of 3.4% (for $\mu=9.6$ GeV).Comment: 38 pages, result extended to allow for an explicit photon energy cut-off, appendix and references added, final result and conlclusions unchange

In patients with combined clavicle and multiple rib fractures, does fracture fixation of the clavicle improve clinical outcomes? A multicenter prospective cohort study of 232 patients

BACKGROUND Clavicle and rib fractures are often sustained concomitantly. The combination of injuries may result in decreased stability of the chest wall, making these patients prone to (respiratory) complications and prolonged hospitalization. This study aimed to assess whether adding chest wall stability by performing clavicle fixation improves clinical outcomes in patients with concurrent clavicle and rib fractures. METHODS A prospective multicenter study was performed including all adult patients admitted between January 2018 and March 2021 with concurrent ipsilateral clavicle and rib fractures. Patients treated operatively versus nonoperatively for their clavicle fracture were matched using propensity score matching. The primary outcome was hospital length of stay (HLOS). Secondary outcomes were intensive care unit length of stay, duration of mechanical ventilation, pain, complications, and quality of life at 6 weeks and 12 months of follow-up. RESULTS In total, 232 patients with concomitant ipsilateral clavicle and rib fractures were included. Fifty-two patients (22%) underwent operative treatment of which 39 could be adequately matched to 39 nonoperatively treated patients. No association was observed between clavicle plate fixation and HLOS (mean difference, 2.3 days; 95% confidence interval, -2.1 to 6.8; p = 0.301) or any secondary endpoint. Eight of the 180 nonoperatively treated patients (4%) had a symptomatic nonunion, for which 5 underwent secondary clavicle fixation. CONCLUSION We found no evidence that, in patients with combined clavicle and multiple rib fractures, plate fixation of the clavicle reduces HLOS, pain, or (pulmonary) complications, nor that it improves quality of life. STUDY TYPE Therapeutic/Care Management; Level III