How an antenna launches its input power into radiation: the pattern of the Poynting vector at and near an antenna

In this paper I first address the question of whether the seat of the power radiated by an antenna made of conducting members is distributed over the ``arms'' of the antenna according to -J . E, where J is the specified current density and E is the electric field produced by that source. Poynting's theorem permits only a global identification of the total input power, usually from a localized generator, with the total power radiated to infinity, not a local correspondence of -J . E dv with some specific radiated power, r^2 S . n dO. I then describe a model antenna consisting of two perfectly conducting hemispheres of radius a separated by a small equatorial gap across which occurs the driving oscillatory electric field. The fields and surface current are determined by solution of the boundary value problem. In contrast to the first approach (not a boundary value problem), the tangential electric field vanishes on the metallic surface. There is no radial Poynting vector normal to the surface. Numerical examples are shown to illustrate how the energy flows from the input region of the gap and is guided near the antenna by its ``arms'' until it is launched at larger r/a into the radiation pattern determined by the value of ka.Comment: 24pages, 8 figures, submitted for publicatio

Contribution of oxygen extraction fraction to maximal oxygen uptake in healthy young men

We analysed the importance of systemic and peripheral arteriovenous O2 difference (a- v− O2 and a-vf O2 difference, respectively) and O2 extraction fraction for maximal oxygen uptake ( V˙ O2max ). Fick law of diffusion and the Piiper and Scheid model were applied to investigate whether diffusion vs perfusion limitations vary with V˙ O2max . Articles (n=17) publishing individual data (n=154) on V˙ O2max , maximal cardiac output ( Q˙ max ; indicator-dilution or Fick method), a- v− O2 difference (catheters or Fick equation) and systemic O2 extraction fraction were identified. For the peripheral responses, group-mean data (articles: n=27; subjects: n=234) on leg blood flow (LBF; thermodilution), a-vf O2 difference and O2 extraction fraction (arterial and femoral venous catheters) were obtained. Q˙ max and two-LBF increased linearly by 4.9-6.0 L·min-1 per 1 L·min-1 increase in V˙ O2max (R2 =0.73 and R2 =0.67, respectively; both P<0.001). The a- v− O2 difference increased from 118-168 mL·L-1 from a V˙ O2max of 2-4.5 L·min-1 followed by a reduction (second-order polynomial: R2 =0.27). After accounting for a hypoxemia-induced decrease in arterial O2 content with increasing V˙ O2max (R2 =0.17; P<0.001), systemic O2 extraction fraction increased up to ~90% ( V˙ O2max : 4.5 L·min-1 ) with no further change (exponential decay model: R2 =0.42). Likewise, leg O2 extraction fraction increased with V˙ O2max to approach a maximal value of ~90-95% (R2 =0.83). Muscle O2 diffusing capacity and the equilibration index Y increased linearly with V˙ O2max (R2 =0.77 and R2 =0.31, respectively; both P<0.01), reflecting decreasing O2 diffusional limitations and accentuating O2 delivery limitations. In conclusion, although O2 delivery is the main limiting factor to V˙ O2max , enhanced O2 extraction fraction (≥90%) contributes to the remarkably high V˙ O2max in endurance-trained individuals

Influence of the COVID-19 Lockdown and Restart on the Injury Incidence and Injury Burden in Men's Professional Football Leagues in 2020: The UEFA Elite Club Injury Study.

BACKGROUND: Studies on football and the coronavirus disease 2019 (COVID-19) have mainly focused on the lockdown consequences for player fitness, the resumption of football training, and how to safely restart the league play, but injury data are scarce. OBJECTIVE: To describe the injury incidence and injury burden in men's professional football teams during the pandemic year of 2020. METHODS: Nineteen teams in 12 countries prospectively registered data on player-exposure and time-loss injuries throughout 2020. All major football leagues were paused as a direct response to the pandemic in March 2020 and were thereafter completely cancelled or restarted after a lockdown interval of at least two months. Historical data from 43 teams in the same cohort during the five preceding years (2015-2019) were used as reference. Between-season and within-season comparisons were made for injury incidence (number of injuries per 1000 h) and injury burden (number of absence days per 1000 h) with 95% confidence intervals and interquartile ranges. RESULTS: There was no increased match injury incidence or injury burden following the restart in 2020 compared with other time periods of 2020 and the corresponding periods 2015-2019. There was an increased training injury incidence and injury burden immediately during the lockdown in 2020, and they remained elevated also following the restart, being higher in 2020 compared with 2015-2019, respectively. The injury characteristics during the first months of the new 2020/21 season (August/September-December) were similar between the five teams that cancelled their 2019/20 season in March 2020 and the 14 teams that restarted their season in May/June 2020. CONCLUSIONS: There was no increased match injury incidence or injury burden following the COVID-19 lockdown and restart of the football season in 2020, but training injury incidence and injury burden were elevated and higher than in 2015-2019

Monitoring of biomarkers in heart failure.

The role of biomarkers is increasingly recognized in heart failure (HF) management, for diagnosis, prognostication, and screening of high-risk patients. Beyond natriuretic peptides and troponins, the utility of novel, emerging biomarkers is less established. This document reflects the key points of a Heart Failure Association of the European Society of Cardiology (ESC) consensus meeting on biomarker monitoring in HF

DEVOTE 5: Evaluating the Short-Term Cost-Utility of Insulin Degludec Versus Insulin Glargine U100 in Basal–Bolus Regimens for Type 2 Diabetes in the UK

Introduction: The aim of this study was to evaluate the short-term cost-utility of insulin degludec (degludec) versus insulin glargine 100 units/mL (glargine U100) for the treatment of type 2 diabetes in the basal–bolus subgroup of the head-to-head cardiovascular (CV) outcome trial, DEVOTE. Methods: A cost-utility analysis was conducted over a 2-year time horizon using a decision analytic model to compare costs in patients receiving once daily degludec or glargine U100, both as part of a basal–bolus regimen, in addition to standard care. Clinical outcomes and patient characteristics were taken exclusively from DEVOTE, whilst health-related quality of life utilities and UK-specific costs (expressed in 2016 GBP) were obtained from the literature. The analysis was conducted from the perspective of the National Health Service. Results: Degludec was associated with mean cost savings of GBP 28.78 per patient relative to glargine U100 in patients with type 2 diabetes at high CV risk. Cost savings were driven by the reduction in risk of diabetes-related complications with degludec, which offset the higher treatment costs relative to glargine U100. Degludec was associated with a mean improvement of 0.0064 quality-adjusted life-years (QALYs) compared with glargine U100, with improvements driven predominantly by lower rates of severe hypoglycemia with degludec versus glargine U100. Improvements in quality-adjusted life expectancy combined with cost neutrality resulted in degludec being dominant over glargine U100. Sensitivity analyses demonstrated that the incremental cost-utility ratio was stable to variations in the majority of model inputs. Conclusion: The present short-term modeling analysis found that for the basal–bolus subgroup of patients in DEVOTE, with a high risk of CV events, degludec was cost neutral (no additional costs) compared with glargine U100 over a 2-year time horizon in the UK setting. Furthermore, there were QALY gains with degludec, particularly due to the reduction in the risk of severe hypoglycemia. Funding: Novo Nordisk A/S. Trial Registration: ClinicalTrials.gov identifier, NCT01959529

Achieving energy balance with a high‐fat meal does not enhance skeletal muscle adaptation and impairs glycemic response in a sleep‐low training model

Training with low carbohydrate availability (LCHO) has shown to acutely enhance endurance training skeletal muscle response, but concomitant energy deficit (ED) in LCHO interventions has represented a confounding factor in past research. This study aimed at determining if achieving energy balance with high‐fat (EB‐HF) acutely enhances the adaptive response in LCHO compared to ED low‐fat (ED‐LF). In a crossover design, nine well‐trained males completed a ‘sleep‐low’ protocol: on day 1 they cycled to deplete muscle glycogen while reaching a set energy expenditure (30 kcal/kg of fat free mass (FFM)). Post‐exercise, low carbohydrate, protein‐matched meals completely (EB‐HF, 30 kcal/kg FFM) or partially (ED‐LF, 9 kcal/kg FFM) replaced the energy expended, with the majority of energy derived from fat in EB‐HF. In the morning of day 2, participants exercised fasted and skeletal muscle and blood samples were collected and a carbohydrate‐protein drink was ingested at 0.5h recovery. Muscle glycogen showed no treatment effect (P < 0.001) and decreased from 350 ±98 and 192 ±94 mmol/kg dry‐mass between rest and 0.5 h recovery. Phosphorylation status mTOR and AMPK pathway proteins showed only time effects. mRNA expression of p53 increased after exercise (P = 0.005) and was higher in ED‐LF at 3.5h compared to EB‐HF (P = 0.027). Plasma glucose and insulin AUC (P < 0.04) and peak values (P≤0.05) were higher in EB‐HF after the recovery drink. Achieving energy balance with a high‐fat meal in a ‘train‐low’ (‘sleep‐low’) model did not enhance markers of skeletal muscle adaptation and impaired glycemia in response to a recovery drink following training in the morning

Long-term Cost-effectiveness of Insulin Degludec Versus Insulin Glargine U100 in the UK: Evidence from the Basal-bolus Subgroup of the DEVOTE Trial (DEVOTE 16)

Objectives: To evaluate the cost-effectiveness of insulin degludec (degludec) versus insulin glargine 100 units/mL (glargine U100) in basal–bolus regimens for patients with type 2 diabetes (T2D) at high cardiovascular (CV) risk based on the DEVOTE CV outcomes trial. Methods: A microsimulation model, informed by clinical outcomes from the subgroup of patients using basal–bolus insulin therapy in DEVOTE (NCT01959529) and by the UKPDS Outcomes Model 2 risk equations, was used to model direct costs (2018 GBP) and effectiveness outcomes [quality-adjusted life years (QALYs)] with degludec versus glargine U100 over a 40-year time horizon. The model captured the development of eight diabetes-related complications, death, severe hypoglycemia and insulin dosing. This analysis was conducted from the perspective of National Health Service (NHS) England. Results: Treatment with degludec versus glargine U100 in basal–bolus regimens was associated with improved clinical outcomes at a higher cost per patient [incremental cost effectiveness ratio (ICER): £14,956 GBP/QALY]. Degludec remained cost effective versus glargine U100 in all exploratory sensitivity analyses, with ICERs below the widely accepted willingness-to-pay threshold, although the result was most sensitive to assumptions regarding the persistence of treatment effects. Conclusions: Our long-term modeling analysis suggested that degludec was cost effective (from the perspective of NHS England) versus glargine U100 in basal–bolus regimens for patients with T2D at high CV risk. Our findings raise important questions regarding how to model the health economics of diabetes therapies

A unique cause of hemoperitoneum: spontaneous rupture of a splenic hemangiopericytoma

Non-traumatic hemoperitoneum may be catastrophic if it is not promptly diagnosed and treated. It is critical to identify this clinical picture and treat any active bleeding. We report the first case in the literature (to our knowledge) of spontaneous hemoperitoneum caused by a cystic splenic hemangiopericytoma. Hemangiopericytomas represent a small subset of soft tissue sarcomas. They rarely originate in the spleen as a primary tumor, with only ten cases having been previously described. The difficulty of predicting the prognosis and clinical behavior of these lesions has been repeatedly stressed. The literature concerning this rare and unusual neoplasm is reviewed

Chuanxiongzine relaxes isolated corpus cavernosum strips and raises intracavernous pressure in rabbits

It has been shown that there are many Chinese traditional herbals that can enhance sexual activity. Chuanxiongzine is a vasoactive ingredient that has been isolated and purified from Ligusticum chuanxiong Hort. In previous studies, it has been found that chuanxiongzine was effective in relaxing rabbit corpus cavernosum smooth muscle. We determined the effects of chuanxiongzine on relaxation of isolated corpus cavernosum strips in vitro and on increase of intracavernous pressure (ICP) in vivo in rabbits. Chuanxiongzine caused a concentration-dependent relaxation of phenylephrine precontracted isolated corpus cavernosum strips (EC50 1.58 × 10−4 mol l−1), which were endothelium independent and NO independent. However, the guanylyl cyclase inhibitor 1-H-[1,2,4] oxadiazolo [4,3-a] quinoxalin-1-one significantly shifted the chuanxiongzine concentration–response relationship to the right. Although there was no significant difference in the level of cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP) in isolated corpus cavernosum strips treated with chuanxiongzine or vehicle, chuanxiongzine caused a significant rise in the level of cGMP and cAMP in isolated corpus cavernosum strips pretreated with the activator of adenylyl cyclase forskolin and the source of NO sodium nitroprusside. In an in vivo study, chuanxiongzine dose-dependently raised ICP after the intracavernous injection of its cumulative doses (0.5, 1, 2 and 5 mg kg−1). The ICP increased from baseline to 19.1±3.7, 24.8±2.1, 30.2±4.8 and 39.7±6.1 mm Hg, respectively, and the duration of tumescence ranged from 8.5±2.8 to 22.9±7.3 min. Our results show that chuanxiongzine can relax isolated corpus cavernosum strips of rabbits in vitro and increase ICP of rabbits in vivo, which is neither endothelium dependent nor NO dependent, but may be partly mediated by the inhibition of cAMP phosphodiesterase or cGMP phosphodiesterase