Phosphorus-Doped Nickel Oxide Micro-Supercapacitor: Unleashing the Power of Energy Storage for Miniaturized Electronic Devices.

For an uninterrupted self-powered network, the requirement of miniaturized energy storage device is of utmost importance. This study explores the potential utilization of phosphorus-doped nickel oxide (P-NiO) to design highly efficient durable micro-supercapacitors. The introduction of P as a dopant serves to enhance the electrical conductivity of bare NiO, leading to 11-fold augmentation in volumetric capacitance to 841.92 Fcm-3 followed by significant enhancement of energy and power density from 6.71 to 42.096 mWhcm-3 and 0.47 to 1.046 Wcm-3, respectively. Theoretical calculations used to determine the adsorption energy of OH- ions, revealing higher in case of bare NiO (1.52 eV) as compared to phosphorus-doped NiO (0.64 eV) leading to high electrochemical energy storage performance. The as-designed micro-supercapacitor (MSC) device demonstrates a facile integration with the photovoltaic system for renewable energy storage and smooth transfer to external loads for enlightening the blue LED for ≈1 min. The choice of P-NiO/Ni not only contributes to cost reduction but also ensures minimal lattice mismatch at the interface facilitating high durability up to 15 K cycles along with capacitive retention of ≈100% and coulombic efficiency of 93%. Thus, the heterostructure unveils the possibilities of exploring miniaturized energy storage devices for portable electronics.

Extended exposure to low doses of azacitidine induces differentiation of leukemic stem cells through activation of myeloperoxidase.

Oral azacitidine (oral-Aza) treatment results in longer median overall survival (OS) (24.7 vs. 14.8 months in placebo) in patients with acute myeloid leukemia (AML) in remission after intensive chemotherapy. The dosing schedule of oral-Aza (14 days/28-day cycle) allows for low exposure of Aza for an extended duration thereby facilitating a sustained therapeutic effect. However, the underlying mechanisms supporting the clinical impact of oral-Aza in maintenance therapy remain to be fully understood. In this preclinical work, we explore the mechanistic basis of oral-Aza/extended exposure to Aza through in vitro and in vivo modeling. In cell lines, extended exposure to Aza results in sustained DNMT1 loss, leading to durable hypomethylation, and gene expression changes. In mouse models, extended exposure to Aza, preferentially targets immature leukemic cells. In leukemic stem cell (LSC) models, the extended dose of Aza induces differentiation and depletes CD34+CD38- LSC. Mechanistically, LSC differentiation is driven in part by increased myeloperoxidase (MPO) expression. Inhibition of MPO activity either by using an MPO-specific inhibitor or blocking oxidative stress, a known mechanism of MPO, partly reverses the differentiation of LSC. Overall, our preclinical work reveals novel mechanistic insights into oral-Aza and its ability to target LSC.

Catalytic, Antifungal, and Antiproliferative Activity Studies of a New Family of Mononuclear [VIVO]/[VVO2] Complexes.

Ligands derived from 2-(1-phenylhydrazinyl)pyridine and salicylaldehyde (HL1), 3-methoxysalicylaldehyde (HL2), 5-bromosalicylaldehyde (HL3), and 3,5-di-tert-butylsalicylaldehyde (HL4) react with [VIVO(acac)2] in MeOH followed by aerial oxidation to give [VVO2(L1)] (1), [VVO2(L2)] (2), [VVO2(L3)] (3), and [VVO2(L4)] (4). Complex [VIVO(acac)(L1)] (5) is also isolable from [VIVO(acac)2] and HL1 in dry MeOH. Structures of all complexes were confirmed by single-crystal X-ray and spectroscopic studies. They efficiently catalyze benzyl alcohol and its derivatives' oxidation in the presence of H2O2 to their corresponding aldehydes. Under optimized reaction conditions using 1 as a catalyst precursor, conversion of benzyl alcohol follows the order: 4 (93%) > 2 (90%) > 1 (86%) > 3 (84%) ≈ 5 (84%). These complexes were also evaluated for antifungal and antiproliferative activities. Complex 3 with MIC50 = 16 µg/mL, 4 with MIC50 = 12 µg/mL, and 5 with MIC50 = 16 µg/mL are efficient toward planktonic cells of Candida albicans and Candida tropicalis. On Michigan cancer foundation-7 (MCF-7) cells, they show comparable cytotoxic effects and exhibit IC50 in the 27.3-33.5 µg/mL range, and among these, 4 exhibits the highest cytotoxicity. A similar study on human embryonic kidney cells (HEK293) confirms their less toxicity at lower concentrations (4 to 16 µg/mL) compared to MCF-7.

Identification of benzothiazole derived monosaccharides as potent, selective, and orally bioavailable inhibitors of human and mouse galectin-3; a rare example of using a S···O binding interaction for drug design.

As a result of our continued efforts to pursue Gal-3 inhibitors that could be used to fully evaluate the potential of Gal-3 as a therapeutic target, two novel series of benzothiazole derived monosaccharides as potent (against both human and mouse Gal-3) and orally bioavailable Gal-3 inhibitors, represented by 4 and 5, respectively, were identified. These discoveries were made based on proposals that the benzothiazole sulfur atom could interact with the carbonyl oxygen of G182/G196 in h/mGal-3, and that the anomeric triazole moiety could be modified into an N-methyl carboxamide functionality. The interaction between the benzothiazole sulfur and the carbonyl oxygen of G196 in mGal-3 was confirmed by an X-ray co-crystal structure of early lead 9, providing a rare example of using a S···O binding interaction for drug design. It was found that for both the series, methylation of 3-OH in the monosaccharides caused no loss in h & mGal-3 potencies but significantly improved permeability of the molecules.

Photo-Rechargeable Li-Ion Batteries using TiS2 Cathode.

Photo-rechargeable (solar) battery can be considered as an energy harvesting cum storage system, where it can charge the conventional metal-ion battery using light instead of electricity, without having other parasitic reactions. Here a two-electrode lithium-ion solar battery with multifaceted TiS2 -TiO2 hybrid sheets as cathode. The choice of TiS2 -TiO2 electrode ensures the formation of a type II semiconductor heterostructure while the lateral heterostructure geometry ensures high mass/charge transfer and light interactions with the electrode. TiS2 has a higher lithium binding energy (1.6 eV) than TiO2 (1.03 eV), ensuring the possibilities of higher amount of Li-ion insertion to TiS2 and hence the maximum recovery with the photocharging, as further confirmed by the experiments. Apart from the demonstration of solar solid-state batteries, the charging of lithium-ion full cell with light indicates the formation of lithium intercalated graphite compounds, ensuring the charging of the battery without any other parasitic reactions at the electrolyte or electrode-electrolyte interfaces. Possible mechanisms proposed here for the charging and discharging processes of solar batteries, based on the experimental and theoretical results, indicate the potential of such systems in the forthcoming era of renewable energies.

Porous Carbon Template Decorated with MOF-Driven Bimetallic Phosphide: A Suitable Heterostructure for the Production of Uninterrupted Green Hydrogen via Renewable Energy Storage Device.

Water splitting via an uninterrupted electrochemical process through hybrid energy storage devices generating continuous hydrogen is cost-effective and green approach to address the looming energy and environmental crisis toward constant supply of hydrogen fuel in fuel cell driven automobile sector. The high surface area metal-organic framework (MOF) driven bimetallic phosphides (ZnP2 @CoP) on top of CNT-carbon cloth matrix is utilized as positive and negative electrodes in energy storage devices and overall water splitting. The as-prepared positive electrode exhibits excellent specific capacitances/capacity of 1600 F g-1 /800 C g-1 @ 1A g-1 and the corresponding hybrid device reveals an energy density of 83.03 Wh kg-1 at power density of 749.9 W kg-1 . Simultaneously, the electrocatalytic performance of heterostructure shows overpotentials of 90 mV@HER and 204 mV@OER at current density of 10 and 20 mA cm-2 , respectively in alkaline electrocatalyzer. Undoubtedly, it shows overall water splitting with low cell voltage of 1.53 V@10 mA cm-2 having faradic and solar-to-hydrogen conversion efficiency of 98.81% and 9.94%, respectively. In addition, the real phase demonstration of the overall water-splitting is performed where the electrocatalyzer is connected with a series of hybrid supercapacitor devices powered up by the 6 V standard silicon solar panel to produce uninterrupted green H2 .

Discovery of pyrrolo[2,1-f][1,2,4]triazine-based inhibitors of adaptor protein 2-associated kinase 1 for the treatment of pain.

Adaptor protein 2-associated kinase 1 (AAK1) is a member of the Ark1/Prk1 family of serine/threonine kinases and plays a role in modulating receptor endocytosis. AAK1 was identified as a potential therapeutic target for the treatment of neuropathic pain when it was shown that AAK1 knock out (KO) mice had a normal response to the acute pain phase of the mouse formalin model, but a reduced response to the persistent pain phase. Herein we report our early work investigating a series of pyrrolo[2,1-f][1,2,4]triazines as part of our efforts to recapitulate this KO phenotype with a potent, small molecule inhibitor of AAK1. The synthesis, structure-activity relationships (SAR), and in vivo evaluation of these AAK1 inhibitors is described.

Photodissociation of nitric oxide from designed ruthenium nitrosyl complex: Studies on wound healing and antibacterial activity.

A photoactivable NO releasing complex [Ru(L1-2)(PPh3)(NO)Cl2](PF6)(1a) have been synthesized by complex [RuL1-2(PPh3)2Cl2](1). Newly designed bidentate ligands, i.e., 4-methoxy-N'-phenyl-N'-(pyridin-2-ylmethyl)benzohydrazide(L1) and 4-nitro-N'-phenyl-N'-(pyridin-2-ylmethyl)benzohydrazide (L2) were utilized to synthesize complex (1). Complex (1) was characterized by ESI-MS, and the solid structure of the complex [1a](PF6) was acquired by X-ray crystallography. Different spectroscopic techniques were employed for the identification of ligands (L1 and L2) and complexes (1 and [1a](PF6)). Calculations employing DFT and TD-DFT were made better to understand the electronic properties of the complex [1a](PF6). The photo liberation experiments were screened in the presence of visible light lamp. Griess assay experiment was used to quantify the photo released amount to NO. The photo liberated NO was successfully transferred to reduced myoglobin (Mb). The complex [1a](PF6) at 50 µg/mL concentration was used for wound healing and antimicrobial activity on B16F1 mouse skin cells and Escherichia coli bacteria, respectively. In results, we observed a considerable wound healing activity of [1a](PF6) complex after 36 h of incubation in the light-treated cells compared to the control medium, and also it shows more than 99% inhibition of bacterial cells after 1.5 h of treatment in the presence of light. These study suggested that this complex 1a](PF6) could be utilized for topical delivery of NO for combating several dermatological infections.

A Satellite Account for Health in the United States.

This paper develops a satellite account for the US health sector and measures productivity growth in health care for the elderly population between 1999 and 2012. We measure the change in medical spending and health outcomes for a comprehensive set of 80 conditions. Medical care has positive productivity growth over the time period, with aggregate productivity growth of 1.5% per year. However, there is significant heterogeneity in productivity growth. Care for cardiovascular disease has had very high productivity growth. In contrast, care for people with musculoskeletal conditions has been costly but has not led to improved outcomes.

In-vitro toxicity assessment of a textile dye Eriochrome Black T and its nano-photocatalytic degradation through an innovative approach using Mf-NGr-CNTs-SnO2 heterostructures.

The present study aimed to assess the in-vitro toxicity of a popular azodye, Eriochrome Black T (EBT) which may be an environmental hazard causing water pollution if released by textile industries as waste effluents to nearby water ponds. We explored the toxic potential of EBT at 200, 400 and 800 µg/ml concentrations, which were selected based on quantification of EBT present in the pond water near carpet industries. We investigated the permeability of EBT across the organ barriers and found it to be 6.48 ± 0.44% at the highest concentration. EBT also showed up to 26.46 ± 0.533% hemolytic potential on human RBCs. MTT assay revealed toxicity of up to 64.9 ± 10.12%. A dose-dependent increase in intracellular ROS levels and Caspase 3/7 activity was observed and confocal microscopy also demonstrated a similar trend of cellular apoptosis indicating ROS mediated induction of apoptosis as a mechanism of EBT induced cytotoxicity. After establishing the toxicity of EBT, an innovative nano-photocatalytic approach for dye remediation was applied by using as synthesized Mf-NGr-CNTs-SnO2 heterostructures. This catalyst showed dye degradation potential of up to 82% in 2 h in the presence of sun light. The degraded dye products were tested to have up to 30% reduced cellular toxicity as compared to the parent compound. This work successfully establishes the toxicity of EBT along with devising an innovative approach towards dye degradation where the catalyst is adhered on melamine foam and not being mixed in the effluents directly, thereby, reducing the possibility of catalyst being leached out into the river water.

Outcome of percutaneous pedicle screw fixation for traumatic thoracic and lumbar fractures -six years experience.

OBJECTIVES: This study discusses the experience at our centre with treating traumatic thoracolumbar fractures using percutaneous pedicle screw fixation. METHODS: We reviewed the case notes and imaging retrospectively between January 2013 and June 2019. RESULTS: A total of 257 patients were included, 123 males and 134 females aged between 17 and 70; the mean age was 47.6 years. The majority of injuries were from fall from significant height. The fractures involved the thoracic and lumbar vertebra in 98 and 151 of the cases respectively. Percutaneous pedicle screw fixation was performed either one or two levels above and below the fracture depending on the level of injury. Forty two cases were treated with additional short pedicle screws at the level of fracture. More than 15% (39) of the patients presented with a neurological deficit; more than 80% (32) of those showed post-operative improvement in their neurology as per Frankel Grading system. The mean operative time was 117 min ± 45 min; mean length of hospital stay was 7.2 days ± 3.8 days, with significant improvement in pain. CONCLUSIONS: Percutaneous pedicle screw fixation is a safe surgical option with comparable outcomes to open surgery and a potential reduction in perioperative morbidity.

Information tools for care coordination in patient handover: Is an electronic medical record enough to support nurses?

BACKGROUND: Effectiveness of end-of-shift patient handover between nurses may be impacted by poor communication. This can be improved with the use of information tools, either electronic or paper-based. Few studies have investigated the activities that support patient handover, and fewer have explored how several of these tools used together affects the handover process. PURPOSE: The aim of this study was to understand coordination challenges in end-of-shift patient handover between nurses and the influence of multiple information tools used in that context. METHODOLOGY: A qualitative methodology to investigate phenomena in an acute care hospital in the United States was used in this study. Semistructured interviews were used to elicit insights from 16 nurses. Data were analyzed by coding three types of task dependencies (prerequisite, simultaneous, and shared) and three information tools (electronic medical records [EMRs], Kardex, and printouts of EMR data). RESULTS: In preparation for a handover, nurses were burdened by ensuring that information in the EMR was correct and complete. A one-sheet Kardex was the tool nurses in the study preferred, because the essential information was at hand and it provided structure to the communication. Printouts of EMR data were often physically cumbersome and not useful in their current form, although they may be useful for communicating anomalous data. CONCLUSION: This study provides insights regarding the challenges of care coordination in end-of-shift patient handover between nurses and the usages of a variety of information tools in preparation for handover, as well as the actual handover process. PRACTICE IMPLICATIONS: Multiple interrelated information tools may be used to support patient handover. Health leaders should focus efforts on further advancing protocols for end-of-shift nurse handovers. Health system designers should design information tools to align them with their defined purpose in the handover process. Future work should consider both the information needs of nurses and the goal of improving nurse workflows.

Molecular mechanism of interspecies differences in the binding affinity of TD139 to Galectin-3.

Galectin-3 (Gal-3), a ß-galactoside-binding lectin, has been implicated in a plethora of pathological disorders including fibrosis, inflammation, cancer and metabolic diseases. TD139-a thio-digalactoside inhibitor developed by Galecto Biotech as a potential therapeutic for idiopathic pulmonary fibrosis-is the most advanced small-molecule Gal-3 inhibitor in clinical studies. It binds to human Gal-3 with high affinity but has lower affinity towards mouse and rat homologs, which is also manifested in the differential inhibition of Gal-3 function. Using biophysical methods and high-resolution X-ray co-crystal structures of TD139 and Gal-3 proteins, we demonstrate that a single amino acid change corresponding to A146 in human Gal-3 is sufficient for the observed reduction in the binding affinity of TD139 in rodents. Site-directed mutagenesis of A146V (in human Gal-3) and V160A (in mouse Gal-3) was sufficient to interchange the affinities, mainly by affecting the off rates of the inhibitor binding. In addition, molecular dynamics simulations of both wild-type and mutant structures revealed the sustained favorable noncovalent interactions between the fluorophenyl ring and the active site A146 (human Gal-3 and mouse V160A) that corroborate the finding from biophysical studies. Current findings have ramifications in the context of optimization of drug candidates against Gal-3.

A risk assessment strategy to re-introduce elective neurosurgery patients during COVID-19.

OBJECTIVES: To demonstrate the utilisation of a risk assessment protocol designed to prioritise elective neurosurgical patients against the risks of COVID-19. This tool can be applied to all other surgical specialties. DESIGN: Prospective case series of 166 patients. SETTING: Single-centre tertiary neurosurgical department. PARTICIPANTS: All patients awaiting an elective neurosurgical procedure were included in this study. All emergency or life-threatening neurosurgical pathologies affecting patients were excluded. MAIN OUTCOME MEASURES: The risk assessment tool identified patients with progressive neurology and stratified need for surgery against risk of harm during the COVID-19 pandemic. RESULTS: Using our risk stratification tool, 6.6% patients required expedited surgery and a further 11.4% patients were removed completely from the waiting list. The majority of patients 47%, required surgery within 3 months. CONCLUSIONS: This simple tool encourages surgical departments to establish contact with patients during COVID-19. The clinician acquires up-to-date information regarding patient symptomatology and subsequently determines surgical priority, a timescale required for surgery and overall uses of NHS resources efficiently. We recommend the use of this tool for all neurosurgical departments, with a wider application to other surgical specialties during the ongoing pressures of elective backlogs secondary to the persistent COVID-19 pandemic.

Linear piezoresistive strain sensor based on graphene/g-C3N4/PDMS heterostructure.

Here we report a novel hybrid material consists of 2D graphitic carbon nitride (g-C3N4) and graphene heterostructure that exhibits piezoresistivity superior to graphene and potentially being used as a strain sensor. The g-C3N4 that contains periodically spaced triangular nanopores is used for improving the piezoresistivity of the sensor imparting change in the polarization upon application of strain. In this work, we have investigated graphene/g-C3N4 interfaced materials and quantified its piezoresistive effects through experimental analysis and density functional theory (DFT) based computational studies provide insights into the electronic structures of the hybrid interfaces. We have observed a linear response in electrical resistance for a wide range of uniaxial strains up to ∼25%. The observed increase in resistance upon application of strain corroborates with our computational finding of strain-dependent band gap opening. Further, it has been realized that band-gap opening occurs exclusively in the graphitic layer of the composite materials under strain. However, the g-C3N4 bands remain intact at the interface. The linearity and a considerably small gauge factor (1.89) make graphene/g-C3N4 a promising heterostructure material unlike conventional metal gauge sensor in wide strain pressure sensor devices.

Trends and Racial Differences in First Hospitalization for Stroke and 30-Day Mortality in the US Medicare Population From 1988 to 2013.

PURPOSE: The main purpose of this study was to determine whether there were temporal differences in the rates of first stroke hospitalizations and 30-day mortality after stroke between black and white Medicare enrollees. METHODS: We used a 20% sample of Medicare beneficiaries aged 65 years or older and described the annual rate of first hospitalization for ischemic and hemorrhagic strokes from years 1988 to 2013, as well as 30-day mortality after stroke hospitalization. We used linear tests of trend to determine whether stroke rates changed over time, and tested the interaction term between race and year to determine whether trends differed by race. RESULTS: We identified 1,009,057 incident hospitalizations for ischemic strokes and 147,817 for hemorrhagic strokes. Annual stroke hospitalizations decreased significantly over time for both blacks and whites, and in both stroke subtypes (P-values for all trend <0.001). Reductions in stroke rates were comparable between blacks and whites: among men, the odds ratio for the interaction term for race by year was 1.008 [95% confidence interval (CI), 1.004-1.012] for ischemic and 1.002 (95% CI, 0.999-1.004) for hemorrhagic; for women, it was 1.000 (95% CI, 0.997-1.004) for ischemic and 1.003 (95% CI, 1.001-1.006) for hemorrhagic. Both black men and women experienced greater improvements over time in terms of 30-day mortality after strokes. CONCLUSIONS: Rates of incident hospitalizations for ischemic and hemorrhagic strokes fell significantly over a 25-year period for both black and white Medicare enrollees. Black men and women experienced greater improvements in 30-day mortality after both ischemic and hemorrhagic stroke.

Study of field emission properties of pure graphene-CNT heterostructures connected via seamless interface.

Vertically aligned carbon nanotubes (CNTs) have proven to be one of the best materials for use as an efficient field emitter. To further improve their efficiency as well as long-term use in practical devices, it is necessary to reduce the quantum resistance originating from the interface between electrode and emitters and the entanglement of the CNTs in a bundle texture. Thus, the incorporation of graphene at the bottom of CNT bundles via a seamless carbonaceous interface can easily solve this bottleneck. In this work we have demonstrated for the first time, growth and field emission properties of pure seamless graphene-CNT heterostructures and pure seamless graphene-vertically patterned oriented CNTs heterostructures (SGVCNTs) on Si/SiO2 substrates in contrast to the bare CNT mats and few-layer graphene structures without using any tedious post transfer processes. It was observed that seamless SGVCNTs show better field emission performance in terms of higher current density (236 mA cm-2), lowered turn-on field (0.45 V µm-1) and threshold field (1.931 V µm-1 @100 mA cm-2), and improved field enhancement factor (ߠ∼ 41 315) which is improved ∼4 fold when compared to a bare CNT mat. The significant improvement of the field emission performance of SGVCNTs is mainly attributed to the low resistive seamless C-C covalent carbonaceous interface, the higher number of emitter sites and patterned vertical orientation that leads to long-term stability of the field emitter with minimal loss up to 32 h. This finding could provide an important solution for carbonaceous material based field emitters for real phase device applications.

Development of a RapidFire mass spectrometry assay and a fluorescence assay for the discovery of kynurenine aminotransferase II inhibitors to treat central nervous system disorders.

Kynurenine aminotransferases convert kynurenine to kynurenic acid and play an important role in the tryptophan degradation pathway. Kynurenic acid levels in brain have been hypothesized to be linked to a number of central nervous system (CNS) disorders. Kynurenine aminotransferase II (KATII) has proven to be a key modulator of kynurenic acid levels in brain and, thus, is an attractive target to treat CNS diseases. A sensitive, high-throughput, label-free RapidFire mass spectrometry assay has been developed for human KATII. Unlike other assays, this method is directly applicable to KATII enzymes from different animal species, which allows us to select proper animal model(s) to evaluate human KATII inhibitors. We also established a coupled fluorescence assay for human KATII. The short assay time and kinetic capability of the fluorescence assay provide a useful tool for orthogonal inhibitor validation and mechanistic studies.

Trends in acute myocardial infarction hospitalizations: Are we seeing the whole picture?

BACKGROUND: Payers and policy makers rely on studies of trends in acute myocardial infarction (AMI) hospitalizations and spending that count only hospitalizations where the AMI is the principal discharge diagnosis. Hospitalizations with AMI coded as a secondary diagnosis are ignored. The effects of excluding these hospitalizations on estimates of trends are unknown. METHODS: Observational study of all AMI hospitalizations in Fee-for-Service Medicare beneficiaries 65 years and older, from 2002 through 2011. RESULTS: We studied 3,663,137 hospitalizations with any AMI discharge diagnosis over 288,873,509 beneficiary-years. Of these, 66% had AMI coded as principal (versus secondary). From 2002 to 2011, AMI hospitalization rates declined 24.5% (from 1,485 per 100,000 beneficiary-years in 2002 to 1,122 in 2011). Meanwhile, the proportion of these hospitalizations with a secondary AMI diagnosis increased from 28% to 40%; by 2011 these secondary AMI hospitalizations accounted for 43% of all expenditures for hospitalizations with AMI, or $2.8 billion. Major changes in comorbidities, principal diagnoses and mean costs for hospitalizations with a non-principal AMI diagnosis occurred in the 2006-2008 timeframe. CONCLUSIONS: Current estimates of the burden of AMI ignore an increasingly large proportion of overall AMI hospitalizations and spending. Changes in the characteristics of hospitalizations that coincided with major payment and policy changes suggest that non-clinical factors affect AMI coding. Failing to consider all AMIs could inflate estimates of population health improvements, overestimate the value of AMI prevention and treatment and underestimate current and future AMI burden and expenditures.

Follow-up compliance after endovascular abdominal aortic aneurysm repair in Medicare beneficiaries.

OBJECTIVE: Lifelong imaging follow-up is essential to the safe and appropriate management of patients who undergo endovascular abdominal aortic aneurysm repair (EVAR). We sought to evaluate the rate of compliance with imaging follow-up after EVAR and to identify factors associated with being lost to imaging follow-up. METHODS: We identified a 20% sample of continuously enrolled Medicare beneficiaries who underwent EVAR between 2001 and 2008. Using data through 2010 from Medicare Inpatient, Outpatient, and Carrier files, we identified all abdominal imaging studies that may have been performed for EVAR follow-up. Patients were considered lost to annual imaging follow-up if they did not undergo any abdominal imaging study within their last 2 years of follow-up. Multivariable models were constructed to identify independent factors associated with being lost to annual imaging follow-up. RESULTS: Among 19,962 patients who underwent EVAR, the incidence of loss to annual imaging follow-up at 5 years after EVAR was 50%. Primary factors associated with being lost to annual imaging follow-up were advanced age (age 65-69 years, reference; age 75-79 years: hazard ratio [HR], 1.23; 95% confidence interval [CI], 1.15-1.32; age 80-85 years: HR, 1.45; 95% CI, 1.35-1.55; age >85 years: HR, 2.03; 95% CI, 1.88-2.20) and presentation with an urgent/emergent intact aneurysm (HR, 1.27; 95% CI, 1.20-1.35) or ruptured aneurysm (HR, 1.84; 95% CI, 1.63-2.08). Additional independent factors included several previously diagnosed chronic diseases and South and West regions of the United States. CONCLUSIONS: Annual imaging follow-up compliance after EVAR in the United States is significantly below recommended levels. Quality improvement efforts to encourage improved compliance with imaging follow-up, especially in older patients with multiple comorbidities and in those who underwent EVAR urgently or for rupture, are necessary.