A quinary WTaCrVHf nanocrystalline refractory high-entropy alloy withholding extreme irradiation environments.

In the quest of new materials that can withstand severe irradiation and mechanical extremes for advanced applications (e.g. fission & fusion reactors, space applications, etc.), design, prediction and control of advanced materials beyond current material designs become paramount. Here, through a combined experimental and simulation methodology, we design a nanocrystalline refractory high entropy alloy (RHEA) system. Compositions assessed under extreme environments and in situ electron-microscopy reveal both high thermal stability and radiation resistance. We observe grain refinement under heavy ion irradiation and resistance to dual-beam irradiation and helium implantation in the form of low defect generation and evolution, as well as no detectable grain growth. The experimental and modeling results-showing a good agreement-can be applied to design and rapidly assess other alloys subjected to extreme environmental conditions.

Direct growth of crystalline SiGe nanowires on superconducting NbTiN thin films.

Novel heterostructures created by coupling one-dimensional semiconductor nanowires with a superconducting thin film show great potential toward next-generation quantum computing. Here, by growing high-crystalline SiGe nanowires on a NbTiN thin film, the resulting heterostructure exhibits Ohmic characteristics as well as a shift of the superconducting transition temperature (Tc). The structure was characterized at atomic resolution showing a sharp SiGe/NbTiN interface without atomic interdiffusion. Lattice spacing, as calculated from large-area x-ray diffraction experiments, suggests a potential preferredd-spacing matching between (200) NbTiN and (110) SiGe grains. The observed out-of-plane compressive strain within the NbTiN films coupled with SiGe nanowires explains the downward shift of the superconductivity behavior. The presented results post scientific insights toward functional heterostructures by coupling multi-dimensional materials, which could enable tunable superconductivity that benefits the quantum science applications.

A controlled nucleation and growth of Si nanowires by using a TiN diffusion barrier layer for lithium-ion batteries.

Uniform size of Si nanowires (NWs) is highly desirable to enhance the performance of Si NW-based lithium-ion batteries. To achieve a narrow size distribution of Si NWs, the formation of bulk-like Si structures such as islands and chunks needs to be inhibited during nucleation and growth of Si NWs. We developed a simple approach to control the nucleation of Si NWs via interfacial energy tuning between metal catalysts and substrates by introducing a conductive diffusion barrier. Owing to the high interfacial energy between Au and TiN, agglomeration of Au nanoparticle catalysts was restrained on a TiN layer which induced the formation of small Au nanoparticle catalysts on TiN-coated substrates. The resulting Au catalysts led to the nucleation and growth of Si NWs on the TiN layer with higher number density and direct integration of the Si NWs onto current collectors without the formation of bulk-like Si structures. The lithium-ion battery anodes based on Si NWs grown on TiN-coated current collectors showed improved specific gravimetric capacities (>30%) for various charging rates and enhanced capacity retention up to 500 cycles of charging-discharging.

Towards performing high-resolution inelastic X-ray scattering measurements at hard X-ray free-electron lasers coupled with energetic laser drivers.

High-resolution inelastic X-ray scattering is an established technique in the synchrotron community, used to investigate collective low-frequency responses of materials. When fielded at hard X-ray free-electron lasers (XFELs) and combined with high-intensity laser drivers, it becomes a promising technique for investigating matter at high temperatures and high pressures. This technique gives access to important thermodynamic properties of matter at extreme conditions, such as temperature, material sound speed, and viscosity. The successful realization of this method requires the acquisition of many identical laser-pump/X-ray-probe shots, allowing the collection of a sufficient number of photons necessary to perform quantitative analyses. Here, a 2.5-fold improvement in the energy resolution of the instrument relative to previous works at the Matter in Extreme Conditions (MEC) endstation, Linac Coherent Light Source (LCLS), and the High Energy Density (HED) instrument, European XFEL, is presented. Some aspects of the experimental design that are essential for improving the number of photons detected in each X-ray shot, making such measurements feasible, are discussed. A careful choice of the energy resolution, the X-ray beam mode provided by the XFEL, and the position of the analysers used in such experiments can provide a more than ten-fold improvement in the photometrics. The discussion is supported by experimental data on 10 µm-thick iron and 50 nm-thick gold samples collected at the MEC endstation at the LCLS, and by complementary ray-tracing simulations coupled with thermal diffuse scattering calculations.

An early relook identifies high-risk trajectories in ambulatory advanced heart failure.

INTRODUCTION: Patients with ambulatory advanced heart failure (HF) are increasingly considered for durable mechanical circulatory support (MCS) and heart transplantation and their effective triage requires careful assessment of the clinical trajectory. METHODS: REVIVAL, a prospective, observational study, enrolled 400 ambulatory advanced HF patients from 21 MCS/transplant centers in 2015-2016. Study design included a clinical re-assessment of Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profile within 120 days after enrollment. The prognostic impact of a worsening INTERMACS Profile assigned by the treating physician was assessed at 1 year after the Early Relook. RESULTS: Early Relook was done in 325 of 400 patients (81%), of whom 24% had a worsened INTERMACS Profile, associated with longer HF history and worse baseline INTERMACS profile, but no difference in baseline LVEF (median 0.20), 6-minute walk, quality of life, or other baseline parameters. Early worsening predicted higher rate of the combined primary endpoint of death, urgent MCS, or urgent transplant by 1 year after Early Relook, (28% vs 15%), with hazard ratio 2.2 (95% CI 1.2- 3.8; p = .006) even after adjusting for baseline INTERMACS Profile and Seattle HF Model score. Deterioration to urgent MCS occurred in 14% vs 5% (p = .006) during the year after Early Relook. CONCLUSIONS: Early Relook identifies worsening of INTERMACS Profile in a significant population of ambulatory advanced HF, who had worse outcomes over the subsequent year. Early reassessment of ambulatory advanced HF patients should be performed to better define the trajectory of illness and inform triage to advanced therapies.

Predictive Value of Cardiopulmonary Exercise Testing Parameters in Ambulatory Advanced Heart Failure.

OBJECTIVES: This study sought to determine cardiopulmonary exercise (CPX) predictors of the combined outcome of durable mechanical circulatory support (MCS), transplantation, or death at 1 year among patients with ambulatory advanced heart failure (HF). BACKGROUND: Optimal CPX predictors of outcomes in contemporary ambulatory advanced HF patients are unclear. METHODS: REVIVAL (Registry Evaluation of Vital Information for ventricular assist devices [VADs] in Ambulatory Life) enrolled 400 systolic HF patients, INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support) profiles 4-7. CPX was performed by 273 subjects 2 ± 1 months after study enrollment. Discriminative power of maximal (peak oxygen consumption [peak VO2]; VO2 pulse, circulatory power [CP]; peak systolic blood pressure â€¢ peak VO2], peak end-tidal pressure CO2 [PEtCO2], and peak Borg scale score) and submaximal CPX parameters (ventilatory efficiency [VE/VCO2 slope]; VO2 at anaerobic threshold [VO2AT]; and oxygen uptake efficiency slope [OUES]) to predict the composite outcome were assessed by univariate and multivariate Cox regression and Harrell's concordance statistic. RESULTS: At 1 year, there were 39 events (6 transplants, 15 deaths, 18 MCS implantations). Peak VO2, VO2AT, OUES, peak PEtCO2, and CP were higher in the no-event group (all p < 0.001), whereas VE/VCO2 slope was lower (p < 0.0001); respiratory exchange ratio was not different. CP (hazard ratio [HR]: 0.89; p = 0.001), VE/VCO2 slope (HR: 1.05; p = 0.001), and peak Borg scale score (HR: 1.20; p = 0.005) were significant predictors on multivariate analysis (model C-statistic: 0.80). CONCLUSIONS: Among patients with ambulatory advanced HF, the strongest maximal and submaximal CPX predictor of MCS implantation, transplantation, or death at 1 year were CP and VE/VCO2, respectively. The patient-reported measure of exercise effort (Borg scale score) contributed substantially to the prediction of outcomes, a surprising and novel finding that warrants further investigation. (Registry Evaluation of Vital Information for VADs in Ambulatory Life [REVIVAL]; NCT01369407).

Arsenic Concentrations in Ground and Surface Waters across Arizona Including Native Lands.

Parts of the Southwestern United States report arsenic levels in water resources that are above the United States Environmental Protection Agency's current drinking water limits. Prolonged exposure to arsenic through food and drinking water can contribute to significant health problems including cancer, developmental effects, cardiovascular disease, neurotoxicity, and diabetes. In order to understand exposure risks, water sampling and testing has been conducted throughout Arizona. This information is available to the public through often non-overlapping databases that are difficult to access and in impracticable formats. The current study utilized a systemic compilation of online databases to compile a spreadsheet containing over 33,000 water samples. The reported arsenic concentrations from these databases were collected from 1990-2017. Using ArcGIS software, these data were converted into a map shapefile and overlaid onto a map of Arizona. This visual representation shows that arsenic levels in surface and ground water exceed the United States Environmental Protection Agency's drinking water limits for many sites in several counties in Arizona, and there is an underrepresentation of sampling in several tribal jurisdictions. This information is useful for water managers and private well owners throughout the State for determining safe drinking water sources and limiting exposure to arsenic.

Combining Laue diffraction with Bragg coherent diffraction imaging at 34-ID-C.

Measurement modalities in Bragg coherent diffraction imaging (BCDI) rely on finding a signal from a single nanoscale crystal object which satisfies the Bragg condition among a large number of arbitrarily oriented nanocrystals. However, even when the signal from a single Bragg reflection with (hkl) Miller indices is found, the crystallographic axes on the retrieved three-dimensional (3D) image of the crystal remain unknown, and thus localizing in reciprocal space other Bragg reflections becomes time-consuming or requires good knowledge of the orientation of the crystal. Here, the commissioning of a movable double-bounce Si (111) monochromator at the 34-ID-C endstation of the Advanced Photon Source is reported, which aims at delivering multi-reflection BCDI as a standard tool in a single beamline instrument. The new instrument enables, through rapid switching from monochromatic to broadband (pink) beam, the use of Laue diffraction to determine crystal orientation. With a proper orientation matrix determined for the lattice, one can measure coherent diffraction patterns near multiple Bragg peaks, thus providing sufficient information to image the full strain tensor in 3D. The design, concept of operation, the developed procedures for indexing Laue patterns, and automated measuring of Bragg coherent diffraction data from multiple reflections of the same nanocrystal are discussed.

Characterization of soft tissue tumours with ultrasound, shear wave elastography and MRI.

OBJECTIVE: To predict accurately whether a soft tissue mass was benign or malignant and to characterize its type using ultrasound, shear wave elastography and MRI. We hypothesized that with the addition of shear wave elastography, it would be possible to determine a threshold velocity value to classify a lesion as benign or malignant. MATERIALS AND METHODS: A total of 151 consecutive, consenting adult patients were prospectively recruited to this study in a tertiary referral musculoskeletal oncology centre. All lesions were assessed with ultrasound, including B mode, Doppler and shear wave elastography measurements. One hundred thirty-eight patients also underwent MRI of the lesion. A histological diagnosis was obtained for all lesions. RESULTS: Malignant lesions were larger than benign lesions and had a greater Doppler activity. There was no useful threshold shear wave velocity to differentiate between benign and malignant lesions. Longitudinal and transverse shear wave velocities were strongly positively correlated with each other. An inverse correlation was shown with lesion size and depth, regardless of whether it was benign or malignant. A logistic regression model combining the ultrasound and MRI characteristics did not confidently classify a lesion as benign or malignant and was inferior to expert opinion. CONCLUSION: The strongest predictors of malignancy are large lesion size and high vascularity. The combination of all ultrasound characteristics (including shear wave elastography) and MRI features does not confidently classify a lesion as benign or malignant, and histological diagnosis remains the gold standard.

Quality of life and treatment preference for ventricular assist device therapy in ambulatory advanced heart failure: A report from the REVIVAL study.

BACKGROUND: The Registry Evaluation of Vital Information for Ventricular Assist Devices (VADs) in Ambulatory Life study is a prospective multicenter cohort of 400 ambulatory patients with advanced chronic systolic heart failure (HF). The aim of the study is to better understand disease trajectory and optimal timing of advanced HF therapies. We examined patient health-related quality of life (HRQOL) data collected at enrollment and their association with patient treatment preferences for VAD placement. METHODS: Baseline assessment of HRQOL included the Kansas City Cardiomyopathy Questionnaire (KCCQ) and the EuroQol EQ-5D-3L Visual Analogue Scale (VAS), along with patient self-assessment of remaining life (PSARL). Descriptive statistics were used to present baseline HRQOL data and Spearman correlation tests to assess the association between KCCQ, VAS, and VAD treatment preference with patient clinical characteristics of interest. RESULTS: The median age was 60 years, 75% were male, and the median left ventricular ejection fraction was 20%. The median (25th percentile, 75th percentile), baseline KCCQ summary score was 64 (48, 78), VAS score 65 (50, 75), and PSARL 7 years (5, 10). There were statistically significant associations of baseline KCCQ and VAS with New York Heart Association class and Interagency Registry of Mechanically Assisted Circulatory Support profile (p < 0.005 for all comparisons). Baseline KCCQ and VAS revealed a modest association with PSARL (correlation = 0.45 and 0.35, respectively; p < 0.001), and many patients were overly optimistic about their expected survival. VAD treatment preference was associated with KCCQ scores (p < 0.031), but the absolute differences were small. VAD treatment preference was independent of other key clinical characteristics such as subject age, VAS, and PSARL. CONCLUSIONS: We found a lack of strong association between HRQOL and patient preference for VAD therapy. Better understanding of patients' perceptions of their illness and how this relates to HRQOL outcomes, clinician risk assessment, and patient decision-making is needed. This may in turn allow better guidance toward available HF therapies in this vulnerable population.

Impact of Socioeconomic Factors on Patient Desire for Early LVAD Therapy Prior to Inotrope Dependence.

BACKGROUND: Worsening heart failure (HF) and health-related quality of life (HRQOL) have been shown to impact the decision to proceed with left ventricular assist device (LVAD) implantation, but little is known about how socioeconomic factors influence expressed patient preference for LVAD. METHODS AND RESULTS: Ambulatory patients with advanced systolic HF (n=353) reviewed written information about LVAD therapy and completed a brief survey to indicate whether they would want an LVAD to treat their current level of HF. Ordinal logistic regression analyses identified clinical and demographic predictors of LVAD preference. Higher New York Heart Association (NYHA) class, worse HRQOL measured by Kansas City Cardiomyopathy Questionnaire, lower education level, and lower income were significant univariable predictors of patients wanting an LVAD. In the multivariable model, higher NYHA class (OR [odds ratio]: 1.43, CI [confidence interval]: 1.08-1.90, P = .013) and lower income level (OR: 2.10, CI: 1.18 - 3.76, P = .012 for <$40,000 vs >$80,000) remained significantly associated with wanting an LVAD. CONCLUSION: Among ambulatory patients with advanced systolic HF, treatment preference for LVAD was influenced by level of income independent of HF severity. Understanding the impact of socioeconomic factors on willingness to consider LVAD therapy may help tailor counseling towards individual needs.

Registry Evaluation of Vital Information for VADs in Ambulatory Life (REVIVAL): Rationale, design, baseline characteristics, and inclusion criteria performance.

INTRODUCTION: Improved understanding of the clinical course of ambulatory advanced chronic systolic heart failure may improve the provision of appropriate care and is central to the design of clinical trials in this population. METHODS: Twenty-one implanting ventricular assist device (VAD) centers enrolled 400 subjects in the Registry Evaluation of Vital Information for VADs in Ambulatory Life (REVIVAL), a prospective, observational study in ambulatory, chronic, advanced systolic heart failure, designed to identify a cohort with an approximately 25% 1-year risk of the primary composite outcome of death, urgent transplant, or durable mechanical circulatory support. Inclusion criteria utilized only information collected during routine clinical care. Exclusion criteria identified patients with contraindications to VAD. Study inclusion required at least 1 of 10 high-risk criteria derived from established hospitalization and non-hospitalization markers of increased mortality risk. We evaluated the test performance characteristics of the high-risk criteria. RESULTS: Data on 373 subjects evaluable for the primary composite outcome at the 1-year visit are presented. Baseline data were consistent with a less advanced cohort than Medical Arm for Mechanically Assisted Circulatory Support or Risk Assessment (MedaMACS) and Comparative Effectiveness of Left Ventricular Assist Device and Medical Management in Ambulatory Heart Failure Patients (ROADMAP). Freedom from the primary composite outcome was 75.9%. Non-hospitalization inclusion criteria identified 89% of patients with events. CONCLUSIONS: Using routinely obtained clinical information for enrollment, REVIVAL successfully recruited an ambulatory chronic systolic heart failure cohort with an approximately 25% annual risk of the primary composite outcome. Information from this registry will be relevant to the planning of future trials of earlier VAD use and of other interventions in this population.

'Desculturización,' urbanization, and nutrition transition among urban Kichwas Indigenous communities residing in the Andes highlands of Ecuador.

BACKGROUND: The nutrition transition continues to affect populations throughout the world. The added impact of market integration and urbanization exacerbates the impact of the nutrition transition upon Indigenous populations worldwide. OBJECTIVES: This study aims to explore the nutritional concerns of the urban Kichwas community residing in the Andes highlands of Ecuador. STUDY DESIGN: This is a qualitative study. METHODS: Eight focus groups were conducted with Kichwas men and women in November 2015 in the Imbabura province of the Andes in Ecuador. DATA ANALYSIS: Applied thematic analysis was used to analyze findings regarding nutrition. RESULTS: The participants shared concerns regarding increased intake of fast food, poor meal timing, and a shift in the child's food preferences that rejects traditional foods. They attributed these concerns to urbanization resulting from an increase in dual-income households and a loss of cultural identity. CONCLUSIONS: Synergistic cultural factors are related to nutritional concerns voiced by the urban Kichwas community. PUBLIC HEALTH IMPLICATIONS: Syndemic theory is a useful interpretive lens regarding nutritional trends within the Kichwas communities as they relate to the increased risk of chronic disease.

Current and Future Considerations in the Use of Mechanical Circulatory Support Devices: An Update, 2008-2018.

Our review in the 2008 volume of this journal detailed the use of mechanical circulatory support (MCS) for treatment of heart failure (HF). MCS initially utilized bladder-based blood pumps generating pulsatile flow; these pulsatile flow pumps have been supplanted by rotary blood pumps, in which cardiac support is generated via the high-speed rotation of computationally designed blading. Different rotary pump designs have been evaluated for their safety, performance, and efficacy in clinical trials both in the United States and internationally. The reduced size of the rotary pump designs has prompted research and development toward the design of MCS suitable for infants and children. The past decade has witnessed efforts focused on tissue engineering-based therapies for the treatment of HF. This review explores the current state and future opportunities of cardiac support therapies within our larger understanding of the treatment options for HF.

Risk and resiliency: the syndemic nature of HIV/AIDS in the indigenous highland communities of Ecuador.

OBJECTIVES: This community-based study explores the syndemic nature of HIV/AIDS risk and resilience among Indigenous Kichwa communities in the province of Imbabura, Ecuador. This study elucidates individual and community-level factors that serve to exacerbate HIV/AIDS risk, as they relate to underlying macrolevel, structural forces. Critically, this study also elicited opportunities for community-based opportunities for resiliency from HIV/AIDS. STUDY DESIGN: Exploratory qualitative study. METHODS: Guided by syndemic theory, a qualitative study was conducted to explore HIV risk and resilience among Indigenous Kichwa communities in the Northern Andean highlands of Ecuador. Eight focus groups (n = 59) with men and women from two communities were conducted. The data were analyzed using applied thematic analysis techniques. RESULTS: Identified risk factors for HIV/AIDS centered around the following themes: (1) parents leaving the community for work, (2) alcohol and drug consumption, (3) unprotected sex, and (4) barriers to health care. Identified HIV/AIDS resiliency factors included the preservation of Indigenous culture and family-focused interventions. CONCLUSIONS: The identified risk factors for HIV/AIDS are interrelated within a complex syndemic relationship. The mutually reinforcing individual-level risk factors of substance abuse and risky sexual behavior coalesce with violence to exacerbate the risk for HIV/AIDS acquisition among Ecuadorian Highland Indigenous communities. Moreover, HIV/AIDS risk prevails in the macrolevel context of disproportionate unemployment among Indigenous peoples and a systematically fragmented healthcare system. It is critical that public health professionals work to revolutionize the systematic discrimination that underpins indigenous health disparities at-large.

Ambulatory Advanced Heart Failure in Women: A Report From the REVIVAL Registry.

OBJECTIVES: This study sought to explore clinical characteristics and outcomes in women and men with ambulatory advanced heart failure (HF). BACKGROUND: Women have been underrepresented in studies of advanced HF and have an increased mortality on the transplant waiting list and early after mechanical circulatory support (MCS). An increased understanding of the differential burden of HF between women and men is required to inform the use of mechanical circulatory support in ambulatory advanced HF patients. METHODS: REVIVAL (Registry Evaluation for Vital Information on Ventricular Assist Devices in Ambulatory Life) is a prospective, observational study of 400 outpatients with chronic systolic HF, New York Heart Association functional class II to IV, and 1 additional high-risk feature. Clinical characteristics, quality of life, and functional capacity were compared between women and men, as was a primary composite endpoint of death, durable MCS, or urgent heart transplantation at 1 year. RESULTS: REVIVAL enrolled 99 women (25% of the cohort) who had similar age, ejection fraction, INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support) profiles, medication use, and willingness to consider MCS as the men enrolled; however, women reported significantly greater limitations in quality of life with respect to physical limitation, reduced 6-min walk distance, and more frequent symptoms of depression. Nevertheless, 1-year combined risk of death, durable MCS, or urgent transplantation did not differ between women and men (24% vs. 22%; p = 0.94). CONCLUSIONS: This study represents the largest report to date of women with ambulatory advanced HF receiving contemporary therapies. Systematic elicitation of patient-reported outcome measures uncovered an added burden of HF in women and may be an appropriate target of augmented support and intervention.

Outstanding radiation resistance of tungsten-based high-entropy alloys.

A body-centered cubic W-based refractory high entropy alloy with outstanding radiation resistance has been developed. The alloy was grown as thin films showing a bimodal grain size distribution in the nanocrystalline and ultrafine regimes and a unique 4-nm lamella-like structure revealed by atom probe tomography (APT). Transmission electron microscopy (TEM) and x-ray diffraction show certain black spots appearing after thermal annealing at elevated temperatures. TEM and APT analysis correlated the black spots with second-phase particles rich in Cr and V. No sign of irradiation-created dislocation loops, even after 8 dpa, was observed. Furthermore, nanomechanical testing shows a large hardness of 14 GPa in the as-deposited samples, with near negligible irradiation hardening. Theoretical modeling combining ab initio and Monte Carlo techniques predicts the formation of Cr- and V-rich second-phase particles and points at equal mobilities of point defects as the origin of the exceptional radiation tolerance.

Analysis of a capped carbon nanotube by linear-scaling density-functional theory.

The apex region of a capped (5,5) carbon nanotube (CNT) has been modelled with the DFT package ONETEP, using boundary conditions provided by a classical calculation with a conducting surface in place of the CNT. Results from the DFT solution include the Fermi level and the physical distribution and energies of individual orbitals for the CNT tip. Application of an external electric field changes the orbital number of the highest occupied molecular orbital (HOMO) and consequently changes its distribution on the CNT.