Impact of scatter on double-pass image quality and contrast sensitivity measured with a single instrument

We compared objective Double-Pass (DP) image quality data with subjective visual parameters measured within the same modified instrument for different amounts of scatter. The original DP imaging channel of a clinical instrument was maintained intact and two additional channels were included, one for visual testing and another for tear film (TF) imaging by using a retro-illumination technique. Contrast sensitivity (CS) was compared with measurements of the Objective Scattering Index (OSI) obtained from DP retinal images corresponding to different scatter levels induced by pre-defined filters. OSI values were correlated with the change in CS for different spatial frequencies measured with the same instrument. Since TF and DP images were recorded at the same rate, this provided additional information about the dynamic spatial stability of the tear film. This new DP instrument has been proven to provide accuracy and repeatability, and to be suitable for clinical diagnosis, with a complete evaluation of the eye’s performance by a simultaneous objective and subjective assessment under the same experimental conditions.OCIS codes: (330.4460) Ophthalmic optics and devices, (330.7327) Visual optics, ophthalmic instrumentation     

Ultrafast transient absorption of eumelanin suspensions: the role of inverse Raman scattering

An ultrafast investigation is carried out on synthetic eumelanin suspended either in water or in DMSO-methanol. Upon photoexcitation by visible femtosecond pulses, the transient absorption (TA) dynamics of the suspensions are probed in a broad visible spectral range, showing clear nonlinearities. The latter arise from pump-probe interactions that induce the inverse Raman scattering (IRS) effect. We show how eumelanin TA dynamics are modified in proximity of the solvent Stokes and anti-Stokes scattering peaks, demonstrating that IRS affects the sign of TA but not the relaxation times. We compare the results obtained in both suspensions, unveiling the role of the surrounding environment. Eventually, the intrinsic response of synthetic eumelanin to ultrafast photoexcitation is evaluated.OCIS codes: (160.1435) Biomaterials, (320.7150) Ultrafast spectroscopy, (300.6240) Spectroscopy, coherent transient, (190.5890) Scattering, stimulated     

EVIDENCE FOR ISOKINETIC KNEE TORQUE ASYMMETRIES IN MALE LONG DISTANCE‐TRAINED RUNNERS

Purpose/Background

Strength asymmetries are related to knee injuries and such injuries are frequently observed among runners. The purpose of this study was to examine whether long‐distance runners have symmetric performance during knee isokinetic testing at two angular velocities.

Methods

Twenty‐three healthy and well‐trained male long‐distance runners performed open‐chain isokinetic trials for assessment of concentric quadriceps and hamstrings contractions at velocities of 60 °·s^‐1 and 240 °·s^‐1. Data were compared between the lower limbs at different velocities.

Results

Peak torque and total work were similar between the limbs. Asymmetry was observed for knee flexor power at 240 °·s^‐1 (237 ± 45 W and 205 ± 53 W, in the preferred and non‐preferred limb, respectively). Asymmetry indexes for flexor power were different between the velocities tested (13.1% and 2.21% for 240 °·s^‐1 and 60 °·s^‐1, respectively).

Conclusion

A limb asymmetry was observed among runners for knee flexor power, mainly at higher angular velocities (240 °·s^‐1). In addition, H/Q ratios were observed to be contraction velocity dependent.

Level of Evidence

3     

Integral Velocidade-Tempo da Insuficiência Aórtica: Um Novo Marcador Ecocardiográfico na Avaliação da Gravidade da Insuficiência Aórtica

BackgroundEchocardiography is essential for the diagnosis and quantification of aortic regurgitation (AR). Velocity-time integral (VTI) of AR flow could be related to AR severity.ObjectiveThis study aims to assess whether VTI is an echocardiographic marker of AR severity.MethodsWe included all patients with moderate or severe native AR and sinus rhythm who visited our imaging laboratory from January to October 2016. All individuals underwent a complete echocardiogram with AR VTI measurement. The association between VTI and AR severity was analyzed by logistic regression and multivariate regression models. A p-value<0,05 was considered statistically significant.ResultsAmong the 62 patients included (68.5±14.9 years old; 64.5%: moderate AR; 35.5%: severe AR), VTI was higher in individuals with moderate AR compared to those with severe AR (2.2±0.5 m vs. 1.9±0.5 m, p=0.01). Patients with severe AR presented greater values of left ventricular end-diastolic diameter (LVEDD) (56.1±7.1 mm vs. 47.3±9.6 mm, p=0.001), left ventricular end-diastolic volume (LVEDV) (171±36.5 mL vs. 106±46.6 mL, p<0.001), effective regurgitant orifice (0.44±0.1 cm²vs. 0.18±0.1 cm², p=0.002), and regurgitant volume (71.3±25.7 mL vs. 42.5±10.9 mL, p=0.05), as well as lower left ventricular ejection fraction (LVEF) (54.1±11.2% vs. 63.2±13.3%, p=0.012). The VTI proved to be a marker of AR severity, irrespective of LVEDD, LVEDV, and LVEF (odds ratio 0.160, p=0.032) and of heart rate and diastolic blood pressure (DBP) (odds ratio 0.232, p=0.044).ConclusionsThe VTI of AR flow was inversely associated with AR severity regardless of left ventricular diameter and volume, heart rate, DBP, and LVEF. VTI could be a marker of AR severity in patients with native AR and sinus rhythm. (Arq Bras Cardiol. 2020; [online].ahead print, PP.0-0)     

Abdominal obesity is associated with potassium depletion and changes in glucose homeostasis during diuretic therapy

The activation of the renin-angiotensin system (RAS) is an important mechanism that contributes to hypertension in obese individuals. Thiazide diuretics also activate the RAS in response to volume contraction and can lead to a decrease in serum potassium values and glucose metabolism abnormalities. To evaluate the impact of abdominal obesity on potassium depletion and glucose homeostasis in hypertensive patients receiving thiazide therapy, the authors studied 329 hypertensive patients without known diabetes or impaired renal function. Patients were stratified into 2 major groups according to whether they used thiazide diuretic therapy, and each group was further divided in 2 subgroups according to the presence of abdominal obesity. The authors demonstrated that obese patients receiving diuretic therapy had lower plasma potassium levels and higher glucose values compared with nonobese patients receiving diuretic therapy. In conclusion, abdominal obesity predisposes to potassium depletion during diuretic therapy in association with effects on glucose homeostasis.     

Growth hormone secretion in diabetic retinopathy

Summary The plasma HGH response to insulin-induced hypoglycemia (0.2 U/kg) and the 24-h plasma HGH pattern during a normal day have been studied in 14 non obese long-term insulin-dependent diabetics with proliferative retinopathy, mean age 39 ± 2 (ranging between 24 and 50 years). Plasma glucose and FFA were also determined. The results were compared with those of 18 normal subjects of similar age and weight. The mean plasma HGH response to insulin in retinopathic diabetics was slightly lower (with no significant differences) than in controls in whom hypoglycemia was induced with a smaller dose of insulin (0.1 U/kg). This pattern of plasma HGH could be related to the delayed plasma glucose fall observed in retinopathic diabetics in comparison to normal subjects, even if the HGH peak after insulin in both groups (18.61 ± 4.32 ng/ml in retinopathic diabetics, 27.43 ± 4.19 in controls) did not seem to be correlated to the degree of hypoglycemia, but rather to the age of the subjects. Plasma HGH pattern, studied with blood samples taken every three hrs during a normal day, did not reveal differences between the diabetics and controls. Plasma glucose, however, was higher in retinopathic diabetics than in controls in spite of the insulin treatment. These results show that in diabetic patients with retinopathy, increased HGH secretion does not occur in conditions of ordinary life or after insulin-induced hypoglycemia, although the HGH plasma levels observed in retinopathic diabetics could be considered too high in relation to the elevated blood glucose levels. Traduzione a cura degli AA.     

Evaluación de la validez de las funciones SCORE de bajo riesgo y calibrada para población española en las cohortes FRESCO

Introduction and objectives

To assess the validity of the original low-risk SCORE function without and with high-density lipoprotein cholesterol and SCORE calibrated to the Spanish population.

Manejo perioperatorio y periprocedimiento del tratamiento antitrombótico: documento de consenso de SEC,SEDAR, SEACV,SECTCV, AEC,SECPRE, SEPD,SEGO, SEHH,SETH, SEMERGEN,SEMFYC, SEMG,SEMICYUC, SEMI,SEMES, SEPAR,SENEC, SEO,SEPA, SERVEI,SECOT y AEU

During the last few years, the number of patients receiving anticoagulant and antiplatelet therapy has increased worldwide. Since this is a chronic treatment, patients receiving it can be expected to need some kind of surgery or intervention during their lifetime that may require treatment discontinuation. The decision to withdraw antithrombotic therapy depends on the patient's thrombotic risk versus hemorrhagic risk. Assessment of both factors will show the precise management of anticoagulant and antiplatelet therapy in these scenarios. The aim of this consensus document, coordinated by the Cardiovascular Thrombosis Working Group of the Spanish Society of Cardiology, and endorsed by most of the Spanish scientific societies of clinical specialities that may play a role in the patient-health care process during the perioperative or periprocedural period, is to recommend some simple and practical guidelines with a view to homogenizing daily clinical practice.Full English text available from: www.revespcardiol.org/en