Measurement setup for Nernst and Seebeck effect at high temperatures and magnetic fields tested on elemental bismuth and full-Heusler compounds.

In this work, a measurement setup to study the Seebeck and Nernst effect at high temperatures and high magnetic fields is introduced and discussed. The measurement system allows for simultaneous measurements of both thermoelectric effects up to 700 K and magnetic fields up to 12 T. Based on theoretical concepts, measurement equations are derived that counteract constant spurious offset voltages and, therefore, inhibit systematic errors in the measurement setup. The functionality is demonstrated on polycrystalline samples of elemental bismuth as well as various full-Heusler materials, exhibiting an anomalous Nernst effect. In all samples, the measured Seebeck and Nernst coefficients align excellently with the reported values. This allows future research to substantially extend the measured temperature and field intervals, commonly limited to temperatures below room temperature. For the first time, the thermoelectric and thermomagnetic properties of these materials are reported up to temperatures of 560 K.

A microscopic Kondo lattice model for the heavy fermion antiferromagnet CeIn3.

Electrons at the border of localization generate exotic states of matter across all classes of strongly correlated electron materials and many other quantum materials with emergent functionality. Heavy electron metals are a model example, in which magnetic interactions arise from the opposing limits of localized and itinerant electrons. This remarkable duality is intimately related to the emergence of a plethora of novel quantum matter states such as unconventional superconductivity, electronic-nematic states, hidden order and most recently topological states of matter such as topological Kondo insulators and Kondo semimetals and putative chiral superconductors. The outstanding challenge is that the archetypal Kondo lattice model that captures the underlying electronic dichotomy is notoriously difficult to solve for real materials. Here we show, using the prototypical strongly-correlated antiferromagnet CeIn3, that a multi-orbital periodic Anderson model embedded with input from ab initio bandstructure calculations can be reduced to a simple Kondo-Heisenberg model, which captures the magnetic interactions quantitatively. We validate this tractable Hamiltonian via high-resolution neutron spectroscopy that reproduces accurately the magnetic soft modes in CeIn3, which are believed to mediate unconventional superconductivity. Our study paves the way for a quantitative understanding of metallic quantum states such as unconventional superconductivity.

Utility of Hook Sign in the Diagnosis of Median Arcuate Ligament Syndrome.

BACKGROUND: Median arcuate ligament syndrome (MALS) is a clinical syndrome caused by compression of the celiac artery by the median arcuate ligament that often manifests with nonspecific abdominal pain. Identification of this syndrome is often dependent on imaging of compression and upward bending of the celiac artery by lateral computed tomography angiography, the so-called "hook sign." The purpose of this study was to assess the relationship of radiologic characteristics of the celiac artery to clinically relevant MALS. METHODS: An institutional review board-approved retrospective chart review from 2,000 to 2,021 of 293 patients at a tertiary academic center diagnosed with celiac artery compression (CAC) was performed. Patient demographics and symptoms of 69 patients who were diagnosed with symptomatic MALS were compared to 224 patients without MALS (but with CAC) per electronic medical record review. Computed tomography angiography images were reviewed and the fold angle (FA) was measured. The presence of a hook sign (defined as a visual FA < 135°), as well as stenosis (defined as >50% of luminal narrowing on imaging) were recorded. Wilcoxon rank-sum test and Chi-squared test were used for comparative analysis. Logistic model was run to relate the presence of MALS with comorbidities and radiographic findings. RESULTS: Imaging was available in 59 patients (25 males, 34 females) and 157 patients (60 males, 97 females) with and without MALS, respectively. Patients with MALS were more likely to have a more severe FA (120.7 ± 33.6 vs. 134.8 ± 27.9, P = 0.002). Males with MALS were also more likely to have a more severe FA compared with males without MALS (111.1 ± 33.7 vs. 130.4 ± 30.4, P = 0.015). In patients with body mass index (BMI) >25, MALS patients also had narrower FA compared with patients without MALS (112.6 ± 30.5 vs. 131.7 ± 30.3, P = 0.001). The FA was negatively correlated with BMI in patients with CAC. The hook sign and stenosis were associated with diagnosis of MALS (59.3% vs. 28.7%, P < 0.001, and 75.7% vs. 45.2%, P < 0.001, respectively). In logistic regression, pain, stenosis, and a narrow FA were statistically significant predictors of the presence of MALS. CONCLUSIONS: The upward deflection of the celiac artery in patients with MALS is more severe compared with patients without MALS. Consistent with prior literature, this bending of the celiac artery is negatively correlated with BMI in patients with and without MALS. When demographic variables and comorbidities are considered, a narrow FA is a statistically significant predictor of MALS. Regardless of MALS diagnosis, a hook sign was associated with narrower FA. While demographics and imaging findings may inform MALS diagnosis, clinicians should not rely on a visual assessment of a hook sign but should quantitatively measure the anatomic bending angle of the celiac artery to assist with the diagnosis and understand the outcomes.

Hyperspectral imaging in systemic sclerosis-associated Raynaud phenomenon.

BACKGROUND/PURPOSE: Lack of robust, feasible, and quantitative outcomes impedes Raynaud phenomenon (RP) clinical trials in systemic sclerosis (SSc) patients. Hyperspectral imaging (HSI) non-invasively measures oxygenated and deoxygenated hemoglobin (oxyHb and deoxyHb) concentrations and oxygen saturation (O2 sat) in the skin and depicts data as oxygenation heatmaps. This study explored the potential role of HSI in quantifying SSc-RP disease severity and activity. METHODS: Patients with SSc-RP (n = 13) and healthy control participants (HC; n = 12) were prospectively recruited in the clinic setting. Using a hand-held camera, bilateral hand HSI (HyperMed™, Waltham, MA) was performed in a temperature-controlled room (22 °C). OxyHb, deoxyHb, and O2 sat values were calculated for 78-mm2 regions of interest for the ventral fingertips and palm (for normalization). Subjects underwent a cold provocation challenge (gloved hand submersion in 15 °C water bath for 1 min), and repeated HSI was performed at 0, 10, and 20 min. Patients completed two patient-reported outcome (PRO) instruments: the Raynaud Condition Score (RCS) and the Cochin Hand Function Scale (CHFS) for symptom burden assessment. Statistical analyses were performed using the Mann-Whitney U test and a mixed effects model (Stata, College Station, TX). RESULTS: Ninety-two percent of participants were women in their 40s. For SSc-RP patients, 69% had limited cutaneous SSc, the mean ± SD SSc duration was 11 ± 5 years, and 38% had prior digital ulcers-none currently. Baseline deoxyHb was higher, and O2 sat was lower, in SSc patients versus HC (p < 0.05). SSc patients had a greater decline in oxyHb and O2 sat from baseline to time 0 (after cold challenge) with distinct rewarming oxyHb, O2 sat, and deoxyHb trajectories versus HCs (p < 0.01). There were no significant correlations between oxyHb, deoxyHb, and O2 sat level changes following cold challenge and RCS or CHFS scores. CONCLUSION: Hyperspectral imaging is a feasible approach for SSc-RP quantification in the clinic setting. The RCS and CHFS values did not correlate with HSI parameters. Our data suggest that HSI technology for the assessment of SSc-RP at baseline and in response to cold provocation is a potential quantitative measure for SSc-RP severity and activity, though longitudinal studies that assess sensitivity to change are needed.

Factors associated with successful median arcuate ligament release in an international, multi-institutional cohort.

OBJECTIVE: Prior research on median arcuate ligament syndrome has been limited to institutional case series, making the optimal approach to median arcuate ligament release (MALR) and resulting outcomes unclear. In the present study, we compared the outcomes of different approaches to MALR and determined the predictors of long-term treatment failure. METHODS: The Vascular Low Frequency Disease Consortium is an international, multi-institutional research consortium. Data on open, laparoscopic, and robotic MALR performed from 2000 to 2020 were gathered. The primary outcome was treatment failure, defined as no improvement in median arcuate ligament syndrome symptoms after MALR or symptom recurrence between MALR and the last clinical follow-up. RESULTS: For 516 patients treated at 24 institutions, open, laparoscopic, and robotic MALR had been performed in 227 (44.0%), 235 (45.5%), and 54 (10.5%) patients, respectively. Perioperative complications (ileus, cardiac, and wound complications; readmissions; unplanned procedures) occurred in 19.2% (open, 30.0%; laparoscopic, 8.9%; robotic, 18.5%; P < .001). The median follow-up was 1.59 years (interquartile range, 0.38-4.35 years). For the 488 patients with follow-up data available, 287 (58.8%) had had full relief, 119 (24.4%) had had partial relief, and 82 (16.8%) had derived no benefit from MALR. The 1- and 3-year freedom from treatment failure for the overall cohort was 63.8% (95% confidence interval [CI], 59.0%-68.3%) and 51.9% (95% CI, 46.1%-57.3%), respectively. The factors associated with an increased hazard of treatment failure on multivariable analysis included robotic MALR (hazard ratio [HR], 1.73; 95% CI, 1.16-2.59; P = .007), a history of gastroparesis (HR, 1.83; 95% CI, 1.09-3.09; P = .023), abdominal cancer (HR, 10.3; 95% CI, 3.06-34.6; P < .001), dysphagia and/or odynophagia (HR, 2.44; 95% CI, 1.27-4.69; P = .008), no relief from a celiac plexus block (HR, 2.18; 95% CI, 1.00-4.72; P = .049), and an increasing number of preoperative pain locations (HR, 1.12 per location; 95% CI, 1.00-1.25; P = .042). The factors associated with a lower hazard included increasing age (HR, 0.99 per increasing year; 95% CI, 0.98-1.0; P = .012) and an increasing number of preoperative diagnostic gastrointestinal studies (HR, 0.84 per study; 95% CI, 0.74-0.96; P = .012) Open and laparoscopic MALR resulted in similar long-term freedom from treatment failure. No radiographic parameters were associated with differences in treatment failure. CONCLUSIONS: No difference was found in long-term failure after open vs laparoscopic MALR; however, open release was associated with higher perioperative morbidity. These results support the use of a preoperative celiac plexus block to aid in patient selection. Operative candidates for MALR should be counseled regarding the factors associated with treatment failure and the relatively high overall rate of treatment failure.

Prevalence and Characteristics of Patients with Median Arcuate Ligament Syndrome in a Cohort Diagnosed with Celiac Artery Compression.

BACKGROUND: Median arcuate ligament syndrome (MALS) is a frequent differential diagnosis in patients with postprandial abdominal symptoms, but diagnosis remains challenging. The aim of this study was to identify characteristics of patients who had MALS compared with non-MALS patients among a cohort of patients diagnosed with celiac artery compression (CAC). STUDY DESIGN: An IRB-approved retrospective chart review (2000 to 2021) of patients at our institution with a discharge diagnosis of CAC was performed. Medical record review for clinical symptoms and findings consistent with MALS was performed. RESULTS: Two hundred ninety-three patients with a diagnosis of CAC were identified; 59.7% were women, and average age was 63.9 ± 20.2 years. Sixty-nine (23.5%) patients with CAC had MALS. There were no significant differences in sex or race between MALS and non-MALS patients, but MALS patients were younger (55.7 vs 68.1, p < 0.001). There was no significant difference in gastrointestinal comorbidities between the 2 groups. Patients with MALS were less likely to have diabetes (12.5% vs 26.9%), renal disease (4.6% vs 8.2%), hypertension (41.5% vs 70.3%), mesenteric atherosclerotic disease (14% vs 61.9%), and peripheral artery disease (15.0% vs 39.7%). CONCLUSIONS: We demonstrate a novel observation that MALS patients tend to have fewer atherosclerotic characteristics than non-MALS patients with CAC. Patients in our study with MALS were more likely to be younger, women, and presenting with epigastric pain. MALS patients had a significantly lower incidence of diabetes, hypertension, renal disease, mesenteric artery disease, and peripheral arterial disease compared with the non-MALS group. An important clinically relevant feature of MALS patients may be their lack of atherosclerotic phenotype compared with non- MALS patients with CAC.

Kondo quasiparticle dynamics observed by resonant inelastic x-ray scattering.

Effective models focused on pertinent low-energy degrees of freedom have substantially contributed to our qualitative understanding of quantum materials. An iconic example, the Kondo model, was key to demonstrating that the rich phase diagrams of correlated metals originate from the interplay of localized and itinerant electrons. Modern electronic structure calculations suggest that to achieve quantitative material-specific models, accurate consideration of the crystal field and spin-orbit interactions is imperative. This poses the question of how local high-energy degrees of freedom become incorporated into a collective electronic state. Here, we use resonant inelastic x-ray scattering (RIXS) on CePd3 to clarify the fate of all relevant energy scales. We find that even spin-orbit excited states acquire pronounced momentum-dependence at low temperature-the telltale sign of hybridization with the underlying metallic state. Our results demonstrate how localized electronic degrees of freedom endow correlated metals with new properties, which is critical for a microscopic understanding of superconducting, electronic nematic, and topological states.

Postoperative atrial fibrillation following non-cardiac surgery: Predictors and risk of mortality.

BACKGROUND: Postoperative atrial fibrillation (POAF) is a major complication that follows both cardiac and non-cardiac procedures. Many studies have explored POAF after cardiac procedures, however POAF following non-cardiac procedures has been understudied. METHODS: National Inpatient Sample database was utilized to conduct a retrospective study of hospitalizations with diagnosis of POAF following non-cardiac procedures between 2010 and 2015. RESULTS: 294,112 patients met the inclusion criteria. Advanced age, male gender, colonic resections, coagulopathy, fluid and electrolyte disorders and history of congestive heart failure are major predictors of POAF and in-hospital mortality. Race, type of insurance, income quartile and weekend admissions are independent determinants of mortality following POAF. CONCLUSIONS: Development of POAF and mortality is dependent upon a wide range of factors not limited to age and medical comorbidities. Although a patient may be at an increased risk for POAF this does not mean they are at an increased risk for mortality.

Heterogeneity in the guidelines for the management of diabetic foot disease in the Caribbean.

The prevalence of diabetes mellitus, diabetic foot (DF) disease and, as a result, lower extremity amputation rates remain high in the Caribbean. This study was undertaken to determine whether Caribbean countries have designated individuals that monitor DF disease and whether there are DF protocols consistent with the International Working Group on the Diabetic Foot (IWGDF) guidance documents. Relevant DF health care personnel(s) from the CARICOM and Dutch Caribbean countries were called or sent questionnaires regarding the presence of structured programs to monitor and manage DF problems in the population. All 25 countries (100%) responded. 81% of respondents could not identify any Ministry, Hospital or individual initiatives that monitored the DF. Only 9 (36%) countries had any guidelines in place. Only 3 countries with guidelines in place utilized IWGDF guidelines. Only 6 (24%) countries had podiatrists and 10 (40%) had vascular surgery availability. 7 (28%) countries had the components for a multidisciplinary team. The presence or the appointment of a designated individual and/or a multidisciplinary approach within the countries for DF disease was absent in the majority of respondent countries. Only a minority of countries implemented DF guidelines or had expertise available to organize a DF multidisciplinary team. Vascular surgery and podiatric care were noticeably deficient. These may be critical factors in the variability and reduced success in implementation of strategies for managing DF problems and subsequent amputations amongst these Caribbean countries.

Physical properties of {Ti,Zr,Hf}2Ni2Sn compounds.

Physical properties, i.e. electrical resistivity (4.2-800 K), Seebeck coefficient (300-800 K), specific heat (2-110 K), Vickers hardness and elastic moduli (RT), have been defined for single-phase compounds with slightly nonstoichiometric compositions: Ti2.13Ni2Sn0.87, Zr2.025Ni2Sn0.975, and Hf2.055Ni2Sn0.945. From X-ray single crystal and TEM analyses, Ti2+xNi2Sn1-x, x ∼ 0.13(1), is isotypic with the U2Pt2Sn-type (space group P42/mnm, ternary ordered version of the Zr3Al2-type), also adopted by the homologous compounds with Zr and Hf. For all three polycrystalline compounds (relative densities >95%) the electrical resistivity of the samples is metallic-like with dominant scattering from static defects mainly conditioned by off-stoichiometry. Analyses of the specific heat curves Cpvs. T and Cp/T vs. T2 reveal Sommerfeld coefficients of γTi2Ni2Sn = 14.3(3) mJ mol-1 K-2, γZr2Ni2Sn = 10(1) mJ mol-1 K-2, γHf2Ni2Sn = 9.1(5) mJ mol-1 K-2 and low-temperature Debye-temperatures: θLTD = 373(7)K, 357(14)K and 318(10)K. Einstein temperatures were in the range of 130-155 K. Rather low Seebeck coefficients (<15 µV K-1), power factors (pf < 0.07 mW mK-2) and an estimated thermal conductivity of λ < 148 mW cm-1 K-1 yield thermoelectric figures of merit ZT < 0.007 at ∼800 K. Whereas for polycrystalline Zr2Ni2Sn elastic properties were determined by resonant ultrasound spectroscopy (RUS): E = 171 GPa, ν = 0.31, G = 65.5 GPa, and B = 147 GPa, the accelerated mechanical property mapping (XPM) mode was used to map the hardness and elastic moduli of T2Ni2Sn. Above 180 K, Zr2Ni2Sn reveals a quasi-linear expansion with CTE = 15.4 × 10-6 K-1. The calculated density of states is similar for all three compounds and confirms a metallic type of conductivity. The isosurface of elf shows a spherical shape for Ti/Zr/Hf atoms and indicates their ionic character, while the [Ni2Sn]n- sublattice reflects localizations around the Ni and Sn atoms with a large somewhat diffuse charge density between the closest Ni atoms.

Pedigree analysis in the Polish Red cattle population.

The objective of this study was to describe the population structure and inbreeding level of the population of Polish Red Cattle (PRC). The structure of the breed was analysed in the context of the existing genetic resources conservation programme. The level of genetic diversity and the effective population size were also determined. The analyses were carried out based on pedigree records of 9 170 animals. Data and pedigree information were collected during the time period of 1950-2014. Records were collected by the National Research Institute of Animal Production in Balice, Poland. The population structure was analysed using the CFC programme. All the animals were grouped into five classes according to their inbreeding coefficient: the first class included non-inbred animals; and the next classes included inbred animals 0% < F ≤ 5%, 5% < F ≤ 10%, 10% < F ≤ 20%, 20% < F ≤ 30% or F > 30%. The average inbreeding in PRC population was 4% and there were 2 182 (23.8%) inbred animals. The study also included the determination of ancestral paths for the PRC population. The longest ancestral path (LAP) consisted of 12 generations (three animals) while only 229 animals (2.53%) had an LAP comprising at least 10 generations. Therefore, a need exists, particularly in PRC as a small local breed, to manage selection and mating decisions to control future coancestry and inbreeding, which would lead to better handling of the effective population size. The study results showed the possibility of disrupting the balance of the structure of a small population like PRC. Hence, endangered populations need to be monitored on a continuous basis.

Popliteal Artery Occlusion with Collateral Blood Flow in a Reducible Knee Dislocation During Pregnancy: A Case Report.

CASE: A 29-year-old healthy woman, 19 weeks pregnant, sustained a right posterolateral knee dislocation with multiligamentous injury and a complete occlusive injury to the right popliteal artery yet had adequate distal perfusion. She declined operative management for both the knee dislocation and the arterial injury, and successful collaboration between obstetrical, vascular, and orthopaedic surgical services resulted in limb preservation and restoration of function. CONCLUSION: This is a unique case of traumatic complete popliteal artery occlusion with adequate collateral arterial perfusion after a reducible posterolateral knee dislocation in a pregnant patient that resulted in limb preservation with nonoperative management.

Colossal anomalous Nernst effect in a correlated noncentrosymmetric kagome ferromagnet.

The transverse voltage generated by a temperature gradient in a perpendicularly applied magnetic field, termed the Nernst effect, has promise for thermoelectric applications and for probing electronic structure. In magnetic materials, an anomalous Nernst effect (ANE) is possible in a zero magnetic field. We report a colossal ANE in the ferromagnetic metal UCo0.8Ru0.2Al, reaching 23 microvolts per kelvin. Uranium's 5f electrons provide strong electronic correlations that lead to narrow bands, a known route to producing a large thermoelectric response. In addition, uranium's strong spin-orbit coupling produces an intrinsic transverse response in this material due to the Berry curvature associated with the relativistic electronic structure. Theoretical calculations show that in UCo0.8Ru0.2Al at least 148 Weyl nodes, and two nodal lines, exist within 60 millielectron volt of the Fermi level. This work demonstrates that magnetic actinide materials can host strong Nernst and Hall responses due to their combined correlated and topological nature.

Prognostic Value of Radiotracer-Based Perfusion Imaging in Critical Limb Ischemia Patients Undergoing Lower Extremity Revascularization.

OBJECTIVES: The purpose of this study was to evaluate the prognostic value of single-photon emission computed tomography (SPECT)/computed tomography (CT) imaging of angiosome foot perfusion for predicting amputation outcomes in patients with critical limb ischemia (CLI) and diabetes mellitus (DM). BACKGROUND: Radiotracer imaging can assess microvascular foot perfusion and identify regional perfusion abnormalities in patients with critical limb ischemia CLI and DM, but the relationship between perfusion response to revascularization and subsequent clinical outcomes has not been evaluated. METHODS: Patients with CLI, DM, and nonhealing foot ulcers (n = 25) were prospectively enrolled for SPECT/CT perfusion imaging of the feet before and after revascularization. CT images were used to segment angiosomes (i.e., 3-dimensional vascular territories) of the foot. Relative changes in radiotracer uptake after revascularization were evaluated within the ulcerated angiosome. Incidence of amputation was assessed at 3 and 12 months after revascularization. RESULTS: SPECT/CT detected a significantly lower microvascular perfusion response for patients who underwent amputation compared with those who remained amputation free at 3 (p = 0.01) and 12 (p = 0.01) months after revascularization. The cutoff percent change in perfusion for predicting amputation at 3 months was 7.55%, and 11.56% at 12 months. The area under the curve based on the amputation outcome was 0.799 at 3 months and 0.833 at 12 months. The probability of amputation-free survival was significantly higher at 3 (p = 0.002) and 12 months (p = 0.03) for high-perfusion responders than low-perfusion responders to revascularization. CONCLUSIONS: SPECT/CT imaging detects regional perfusion responses to lower extremity revascularization and provides prognostic value in patients with CLI (Radiotracer-Based Perfusion Imaging of Patients With Peripheral Arterial Disease; NCT03622359).

Evidence for a pressure-induced antiferromagnetic quantum critical point in intermediate-valence UTe2.

UTe2 is a recently discovered unconventional superconductor that has attracted much interest because of its potentially spin-triplet topological superconductivity. Our ac calorimetry, electrical resistivity, and x-ray absorption study of UTe2 under applied pressure reveals key insights on the superconducting and magnetic states surrounding pressure-induced quantum criticality at P c1 = 1.3 GPa. First, our specific heat data at low pressures, combined with a phenomenological model, show that pressure alters the balance between two closely competing superconducting orders. Second, near 1.5 GPa, we detect two bulk transitions that trigger changes in the resistivity, which are consistent with antiferromagnetic order, rather than ferromagnetism. Third, the emergence of magnetism is accompanied by an increase in valence toward a U4+ (5f 2) state, which indicates that UTe2 exhibits intermediate valence at ambient pressure. Our results suggest that antiferromagnetic fluctuations may play a more substantial role on the superconducting state of UTe2 than previously thought.

The Role of Lower Extremity Amputation in Chronic Limb-Threatening Ischemia.

Chronic limb-threatening ischemia (CLTI) is a severe form of peripheral artery disease associated with high rates of limb loss. The primary goal of treatment in CLTI is limb salvage via revascularization. Multidisciplinary teams provide improved care for those with CLTI and lead to improved limb salvage rates. Not all patients are candidates for revascularization, and a subset will require major amputation. This article highlights the role of amputations in the management of CLTI, and describes the patients who should be offered primary amputation.

A real world analysis of recurrence risk factors for early colorectal cancer T1 treated with standard endoscopic resection.

BACKGROUND AND STUDY AIM: Currently, endoscopic resection of early colorectal cancer defined as carcinoma with limited invasion of the mucosa (Tis) and submucosa (T1) is possible. However, lymph node spreading increases to 16.2% of cases when tumor invades the submucosa. We analyzed the previously identified factors for lymph node dissemination and recurrence, in our population. PATIENTS AND METHODS: We analyzed retrospectively all patients with T1 tumors, treated at our center with endoscopic resection and some with additional surgery between January 2006 and January 2018. Statistical analysis was performed using IBM SPSS Statistics 25.0. RESULTS: One hundred fifty-nine patients were treated with endoscopic resection, 56.6% with additional surgery. The mean age was 68.74 years and 69. 9% were male. All patients who underwent additional surgery presented negative margins and 8.8% presented positive lymph nodes. In a mean follow-up of 23.36 months, 13 patients had relapsed. The risk of relapse did not differ between patients treated with additional surgery from those who only underwent endoscopic resection (p = 0.506). On the other hand, lymph node dissemination (p = 0.007) and a positive endoscopic margin (p = 0.01) were independent risk factors for relapse. There was a positive association between lymph node dissemination and lymphatic (p = 0.07), vascular (p = 0.007), and perineural (p = 0.001) invasion and also with degree of histological differentiation (p = 0.001). CONCLUSION: In our study, lymphatic, vascular, and perineural invasion and also the degree of histological differentiation were associated with lymph node dissemination. However, the only independent risk factors for long-term recurrence were a positive margin and lymph node dissemination.

Picture recognition of food by sloth bears (Melursus ursinus).

Pictures are often used in cognitive research to represent objects and many species have demonstrated the ability to recognize two-dimensional pictures as representations of their three-dimensional counterparts. However, for ursids picture recognition has been reported in only one study of a single 11-year-old female American black bear (Johnson-Ulrich et al. 2016). We tested the picture recognition abilities of an additional species, the sloth bear. After a food preference test by which the bears' food options were ranked and categorized as high-, mid-, and low-preference items, we tested a sub-adult male and an adult female sloth bear by presenting two pictures of food in each testing trial-a high-preference food and a low-preference food. Both bears met the criterion by choosing the pictures of their preferred foods in at least 80% of the trials in three consecutive testing sessions. We then presented never-before-used pictures of high-preference versus low-preference food items and they again met our criterion.

Thermoelectric performance of a metastable thin-film Heusler alloy.

Thermoelectric materials transform a thermal gradient into electricity. The efficiency of this process relies on three material-dependent parameters: the Seebeck coefficient, the electrical resistivity and the thermal conductivity, summarized in the thermoelectric figure of merit. A large figure of merit is beneficial for potential applications such as thermoelectric generators. Here we report the thermal and electronic properties of thin-film Heusler alloys based on Fe2V0.8W0.2Al prepared by magnetron sputtering. Density functional theory calculations suggest that the thin films are metastable states, and measurements of the power factor-the ratio of the Seebeck coefficient squared divided by the electrical resistivity-suggest a high intrinsic figure of merit for these thin films. This may arise from a large differential density of states at the Fermi level and a Weyl-like electron dispersion close to the Fermi level, which indicates a high mobility of charge carriers owing to linear crossing in the electronic bands.

Constraints on the superconducting order parameter in Sr2RuO4 from oxygen-17 nuclear magnetic resonance.

Phases of matter are usually identified through spontaneous symmetry breaking, especially regarding unconventional superconductivity and the interactions from which it originates. In that context, the superconducting state of the quasi-two-dimensional and strongly correlated perovskite Sr2RuO4 is considered to be the only solid-state analogue to the superfluid 3He-A phase1,2, with an odd-parity order parameter that is unidirectional in spin space for all electron momenta and breaks time-reversal symmetry. This characterization was recently called into question by a search for an expected 'split' transition in a Sr2RuO4 crystal under in-plane uniaxial pressure, which failed to find any such evidence; instead, a dramatic rise and a peak in a single-transition temperature were observed3,4. Here we use nuclear magnetic resonance (NMR) spectroscopy of oxygen-17, which is directly sensitive to the order parameter via hyperfine coupling to the electronic spin degrees of freedom, to probe the nature of superconductivity in Sr2RuO4 and its evolution under strain. A reduction of the Knight shift is observed for all strain values and at temperatures below the critical temperature, consistent with a drop in spin polarization in the superconducting state. In unstrained samples, our results contradict a body of previous NMR work reporting no change in the Knight shift5 and the most prevalent theoretical interpretation of the order parameter as a chiral p-wave state. Sr2RuO4 is an extremely clean layered perovskite and its superconductivity emerges from a strongly correlated Fermi liquid, and our work imposes tight constraints on the order parameter symmetry of this archetypal system.