The Weis-Fogh number describes resonant performance tradeoffs in flapping insects.

Dimensionless numbers have long been used in comparative biomechanics to quantify competing scaling relationships and connect morphology to animal performance. While common in aerodynamics, few relate the biomechanics of the organism to the forces produced on the environment during flight. We discuss the Weis-Fogh number, N, as a dimensionless number specific to flapping flight, which describes the resonant properties of an insect and resulting tradeoffs between energetics and control. Originally defined by Torkel Weis-Fogh in his seminal 1973 paper, N measures the ratio of peak inertial to aerodynamic torque generated by an insect over a wingbeat. In this perspectives piece, we define N for comparative biologists and describe its interpretations as a ratio of torques, and as the width of an insect's resonance curve. We then discuss the range of N realized by insects and explain the fundamental tradeoffs between an insect's aerodynamic efficiency, stability, and responsiveness that arise as a consequence of variation in N, both across and within species. N is therefore an especially useful quantity for comparative approaches to the role of mechanics and aerodynamics in insect flight.

Impairment in quantitative microvascular function in non-ischemic cardiomyopathy as demonstrated using cardiovascular magnetic resonance.

BACKGROUND: Microvascular dysfunction (MVD) is present in various cardiovascular diseases and portends worse outcomes. We assessed the prevalence of MVD in patients with non-ischemic cardiomyopathy (NICM) as compared to subjects with preserved ejection fraction (EF) using stress cardiovascular magnetic resonance (CMR). METHODS: We retrospectively studied consecutive patients with NICM and 58 subjects with preserved left ventricular (LV) EF who underwent stress CMR between 2011-2016. MVD was defined visually as presence of a subendocardial perfusion defect and semiquantitatively by myocardial perfusion reserve index (MPRI<1.51). MPRI was compared between groups using univariate analysis and multivariable linear regression. RESULTS: In total, 41 patients with NICM (mean age 51 ± 14, 59% male) and 58 subjects with preserved LVEF (mean age 51 ± 13, 31% male) were identified. In the NICM group, MVD was present in 23 (56%) and 11 (27%) by semiquantitative and visual evaluation respectively. Compared to those with preserved LVEF, NICM patients had lower rest slope (3.9 vs 4.9, p = 0.05) and stress perfusion slope (8.8 vs 11.7, p<0.001), and MPRI (1.41 vs 1.74, p = 0.02). MPRI remained associated with NICM after controlling for age, gender, hypertension, ethnicity, diabetes, and late gadolinium enhancement (log MPR, ß coefficient = -0.19, p = 0.007). CONCLUSIONS: MVD-as assessed using CMR-is highly prevalent in NICM as compared to subjects with preserved LVEF even after controlling for covariates. Semiquantitative is able to detect a greater number of incidences of MVD compared to visual methods alone. Further studies are needed to determine whether treatment of MVD is beneficial in NICM.

Prevention of Coronary Artery Disease in Women.

PURPOSE OF REVIEW: Cardiovascular disease remains the leading cause of morbidity and mortality in women. Women were historically underrepresented in landmark trials for which cardiovascular guidelines are based on and are prone to gender-specific risk factors that predispose to coronary heart disease. RECENT FINDINGS: More attention has been made on gender and pregnancy-associated risk factors such as autoimmune disorders and preeclampsia. The most recent guidelines have reflected the need to consider risk-enhancing factors that are unaccounted for in traditional risk assessment tools. As the population ages and the burden of cardiovascular disease in women increases, it is crucial to continue focusing on preventative of cardiovascular disease in women.

Heart Failure in Older Adults: Medical Management and Advanced Therapies.

As the population ages and the prevalence of heart failure increases, cardiologists and geriatricians can expect to see more elderly patients with heart failure in their everyday practice. With the advancement of medical care and technology, the options for heart failure management have expanded, though current guidelines are based on studies of younger populations, and the evidence in older populations is not as robust. Pharmacologic therapy remains the cornerstone of heart failure management and has improved long-term mortality. Prevention of sudden cardiac death with implantable devices is being more readily utilized in older patients. Advanced therapies have provided more options for end-stage heart failure, though its use is still limited in older patients. In this review, we discuss the current guidelines for medical management of heart failure in older adults, as well as the expanding literature on advanced therapies, such as heart transplantation in older patients with end-stage heart failure. We also discuss the importance of a multidisciplinary care approach including consideration of non-medical co-morbidities such as frailty and cognitive decline.

Tips for pandemic response planning for Internal Medicine training programs.

This article was migrated. The article was marked as recommended. The current Coronavirus Disease 2019 (COVID-19) pandemic has strained hospital systems and training programs across the world. As capacity issues mount and trainees are called upon to provide frontline medical care, programs and institutions have had to rapidly evolve to redefine the trainee experience. To that end, there is a paucity of literature regarding how healthcare training programs should operate during a global pandemic. Here, we aim to describe twelve evidence-based recommendations for coordinating a cohesive, systematic approach to pandemic response planning for Internal Medicine residency training programs. These tips encompass inpatient and outpatient practices, provider safety, resuscitation, virtual education programming and resident wellbeing. Though many of these considerations or recommendations were not described during the COVID-19 pandemic, these tips have been described previously in the literature, are applicable to the current pandemic and could be easily extrapolated to future crises.

Eleven-year trends of inpatient pacemaker implantation in patients diagnosed with sick sinus syndrome.

BACKGROUND: Pacemakers (PM) are used for managing sick sinus syndrome (SSS). This study evaluates predictors and trends of PM implantation for SSS. METHODS: Patients were identified from the National Inpatient Sample dataset (2003-2013). Included patients were ≥18 years old, had a diagnosis of sinus node dysfunction and atrial arrhythmia (i.e., SSS). Patients who died, transferred out, who had prior device, or had a defibrillator or resynchronization therapy device implanted were excluded. Included patients were then stratified by if a PM was implanted. Data regarding SSS, trends of PM utilization, and multivariable models of factors associated with PM implantation are presented. RESULTS: Note that 328,670 patients satisfied study criteria. This study compared patients who underwent (87.4%) PM implantation to those who did not undergo (12.6%) PM implantation. The annual trends for hospitalization with SSS and PM placement have been decreasing (P <0.001). Variables associated with lower likelihood for PM implantation include young age, female sex, non-Caucasian race, chronic heart failure, Charlson Comorbidity Score ≥1, emergency room and weekend admission, hospital stay ≤3 days, and high cardiology inpatient volume. Greater likelihood for PM implantation was associated with hyperlipidemia, hypertension, and hospitals that were either private, large, Northeastern location, or with high cardiac procedural volume. CONCLUSIONS: Analyzing 11-year data from a national inpatient database demonstrate a number of relevant variables that impact PM utilization that include not only clinical but also nonclinical variables such as socioeconomic status, gender, and hospital features. Racial and gender bias toward PM implantation are unchanged and persist through 2013.

Biotransformation of 6:2 polyfluoroalkyl phosphates (6:2 PAPs): Effects of degradative bacteria and co-substrates.

Polyfluoroalkyl phosphates (PAPs), a group of fluorotelomer alcohol (FTOH)-based surfactants commonly used in water- and grease-proof food contact paper, have been suggested as a direct source of human exposure to health-concerned perfluoroalkyl carboxylic acids (PFCAs). This study investigated factors affecting biotranformation of 6:2 polyfluoroalkyl phosphates (6:2 PAPs) by three known FTOH-degrading Pseudomonas strains (Pseudomonas butanovora, P. oleovorans, and P. fluorescens DSM 8341) under different co-substrate conditions and compared to that by activated sludge samples. The three pure strains transformed 6:2 PAPs into eight different per- and poly-fluoroalkyl carboxylic acids (PFCAs) and/or PFCA precursors. P. fluorescens DSM 8341 produced 5:2 sFTOH [CF3(CF2)4CH(OH)CH3] and P. oleovorans produced 5:2 ketone [CF3(CF2)4C(O)CH3] as the primary transformation product, respectively, with citrate having a minimal impact on the transformation. P. butanovora with lactate produced more diverse transformation products than those by any two strains. Activated sludge was more efficient at transforming 6:2 PAPs and produced more transformation products including PFHpA [CF3(CF2)5COOH] and PFPeA [CF3(CF2)3COOH], with 5:2 sFTOH as the most abundant product on day 30. The abundance of the alkane hydroxylase (alkB) gene related to alkane oxidation, the changes of total microbial population as well as their community structure in activated sludge during 6:2 PAPs biotransformation were also investigated.

Systemic treatment for breast cancer: chemotherapy and biotherapy agents.

OBJECTIVES: To describe current systemic chemotherapy and biotherapy breast cancer treatments to better inform clinical nursing practice. DATA SOURCES: CINAHLl, Medline, Academic Research Periodicals, PubMed Clinical Queries, CANCERLIT, and EBM Reviews-Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews (CDSR). CONCLUSION: Systemic therapeutic options for patients with breast cancer can be complex and varied. Furthermore, the guidelines for the treatment of breast cancer are frequently changing as new chemotherapies and biotherapies are being developed. IMPLICATIONS FOR NURSING PRACTICE: Nursing clinical practice has to remain current to accommodate new treatments and the side effect profiles. This knowledge is essential to providing evidence-based care for breast cancer patients receiving these treatments.

Visualization of high resolution spatial mass spectrometric data during acquisition.

Mass Spectrometric Imaging (MSI) allows the generation of 2D ion density maps that help visualize molecules present in sections of tissues and cells. The combination of spatial resolution and mass resolution results in very large and complex data sets. New capabilities are necessary for efficient analysis and interpretation of this data. This work details the development and application of the capability to process, visualize, query, and analyze spatial mass spectrometry data. Applications include the generation of 2D maps for selected spectra, the manipulation of the heat maps, and the identification of spectral peaks. Heat maps are generated by projecting the sum of intensity vs. time spectra of each pixel for selected m/z value or range. These capabilities take the form of a new interactive software toolkit, MSI QuickView. This software approach is a significant advance over the previous state-of-the art methods that required the conversion of the RAW data using one software, manual assembly of the data, and visualization in another software.