Cardiovascular response in mid and long-distance runners under training / Resposta cardiovascular em corredores de média e longa distância sob treinamento / Respuesta cardiovascular en corredores de media y larga distancia en entrenamiento

ABSTRACT Introduction: Research on the effects of exercise on the cardiovascular system has a long history that has recently been expanded with echocardiography. Research using Doppler echocardiography has been increasing because of the safe and non-invasive method of examination to study cardiac morphology and function. However, few studies on functional cardiac changes in mid and long-distance runners under training are still few. Objective: Study the monitoring of cardiovascular response in middle and long-distance runners during training. Methods: The CFOCS-I cardiovascular function detector was used to observe 24 indices of cardiac pump function, vascular function, and microcirculation in 12 female middle-distance runners. Results: According to the test results, diastolic force, systolic force, systolic function, left ventricular ejection fraction increased during the proposed loading exercise. The mean systolic and mean pulse pressures increased significantly with exercise load (P<0.01). Conclusion: Mid and long-distance runners demonstrated significant cardiac changes in ventricular shape, size, and systolic function, accompanied by significant changes in diastolic function when subjected to intense exercise. Evidence Level II; Therapeutic Studies - Investigating the result.

RESUMO Introdução: A pesquisa dos efeitos do exercício sobre o sistema cardiovascular tem uma longa história que recentemente foi expandida com o uso da ecocardiografia. Pesquisas utilizando a ecocardiografia por doppler têm crescido devido ao método de exame apresentar-se seguro e não-invasivo para estudo de morfologia e função cardíaca. Porém ainda há poucos estudos sobre as alterações cardíacas funcionais em corredores de média e longa distância sob treinamento. Objetivo: Estudar o monitoramento da resposta cardiovascular nos corredores de média e longa distância durante o treinamento. Métodos: O detector de função cardiovascular CFOCS-I foi usado para observar 24 índices de função da bomba cardíaca, função vascular, e microcirculação em 12 corredoras de média distância do sexo feminino. Resultados: De acordo com os resultados dos testes, a força diastólica, a força sistólica, a função sistólica, a fração de ejeção do ventrículo esquerdo aumentaram durante o exercício de carga proposto. A pressão sistólica média e a pressão de pulso média aumentaram significativamente com a carga de exercício (P<0,01). Conclusão: Os corredores de média e longa distância demonstraram alterações cardíacas significativas no formato, tamanho e função sistólica dos ventrículos, acompanhado por mudanças significativas na função diastólica quando submetidos ao exercício intenso. Nível de evidência II; Estudos Terapêuticos - Investigação de Resultados.

RESUMEN Introducción: La investigación sobre los efectos del ejercicio en el sistema cardiovascular tiene una larga historia que se ha ampliado recientemente con el uso de la ecocardiografía. La investigación con ecocardiografía Doppler ha ido en aumento debido a que es un método de examen seguro y no invasivo para estudiar la morfología y la función cardíacas. Sin embargo, todavía hay pocos estudios sobre los cambios funcionales cardíacos en corredores de media y larga distancia bajo entrenamiento. Objetivo: Estudiar el seguimiento de la respuesta cardiovascular en corredores de media y larga distancia durante el entrenamiento. Métodos: Se utilizó el detector de función cardiovascular CFOCS-I para observar 24 índices de la función de la bomba cardíaca, la función vascular y la microcirculación en 12 corredoras de media distancia. Resultados: Según los resultados de la prueba, la fuerza diastólica, la fuerza sistólica, la función sistólica y la fracción de eyección del ventrículo izquierdo aumentaron durante el ejercicio de carga propuesto. La presión sistólica media y la presión de pulso media aumentaron significativamente con la carga de ejercicio (P<0,01). Conclusión: Los corredores de media y larga distancia mostraron cambios cardíacos significativos en la forma, el tamaño y la función sistólica del ventrículo, acompañados de cambios significativos en la función diastólica cuando se sometieron a un ejercicio intenso. Nivel de evidencia II; Estudios terapéuticos - Investigación de resultados.

Fingerprint of the Interbond Electron Hopping in Second-Order Harmonic Generation.

We experimentally explore the fingerprint of the microscopic electron dynamics in second-order harmonic generation (SHG). It is shown that the interbond electron hopping induces a novel source of nonlinear polarization and plays an important role even when the driving laser intensity is 2 orders of magnitude lower than the characteristic atomic field. Our model predicts anomalous anisotropic structures of the SHG yield contributed by the interbond electron hopping, which is identified in our experiments with ZnO crystals. Moreover, a generalized second-order susceptibility with an explicit form is proposed, which provides a unified description in both the weak and strong field regimes. Our work reveals the nonlinear responses of materials at the electron scale and extends the nonlinear optics to a previously unexplored regime, where the nonlinearity related to the interbond electron hopping becomes dominant. It paves the way for realizing controllable nonlinearity on an ultrafast time scale.

Enhancement of the photocurrents injected in gapped graphene by the orthogonally polarized two-color laser field.

We theoretically investigate the photocurrents injected in gapped graphene by the orthogonally polarized two-color laser field. Depending on the relative phase, the photocurrents can be coherently controlled by deforming the electron trajectory in the reciprocal space. Under the same field strength, the peak photocurrent in the orthogonally polarized two-color field is about 20 times larger than that for linearly polarized light, and about 3.6 times for elliptically polarized light. The enhancement of the photocurrent can be attributed to an obvious asymmetric distribution of the real population in the reciprocal space, which is sensitive to the waveform of the laser field and related to the quantum interference between the electron trajectories. Our work provides a noncontact method to effectively enhance the injected current in graphene.

Dynamic Core Polarization in High Harmonic Generation from Solids: The Example of MgO Crystals.

Previously, the strong field processes in solids have always been explained by the single-active-electron (SAE) model with a frozen core excluding the fluctuation of background electrons. In this work, we demonstrate the strong field induced dynamic core polarization effect and propose a model for revealing its role in high harmonic generation (HHG) from solids. We show that the polarized core induces an additional polarization current beyond the SAE model based on the frozen cores. It gives a new mechanism for HHG and leads to new anisotropic structures, which are experimentally observed with MgO. Our experiments indicate that the influences of dynamic core polarization on HHG are obvious for both linearly and elliptically polarized laser fields. Our work establishes the bridge between the HHG and the dynamic changes of the effective many-electron interaction in solids, which paves the way to probe the ultrafast electron dynamics.

Generation of isolated circularly polarized attosecond pulses by three-color laser field mixing.

We propose and theoretically demonstrate a method to generate the circularly polarized supercontinuum with three-color electric fields. The three-color field is synthesized from an orthogonally polarized two-color (OTC) laser field and an infrared gating field. All driving pulse durations are extended to 40 fs. We demonstrate that the three-color field imposes curved trajectories for ionized electrons and extends the time interval between each harmonic emitting. Through adjusting intensity ratios among three components of the driving field, a nearly circular isolated attosecond pulse can be generated.

All-optical measurement of high-order fractional molecular echoes by high-order harmonic generation.

An all-optical measurement of high-order fractional molecular echoes is demonstrated by using high-order harmonic generation (HHG). Excited by a pair of time-delayed short laser pulses, the signatures of full and high order fractional (1/2 and 1/3) alignment echoes are observed in the HHG signals measured from CO 2 molecules at various time delays of the probe pulse. By increasing the time delay of the pump pulses, much higher order fractional (1/4) alignment echo is also observed in N 2O molecules. With an analytic model based on the impulsive approximation, the spatiotemporal dynamics of the echo process are retrieved from the experiment. Compared to the typical molecular alignment revivals, high-order fractional molecular echoes are demonstrated to dephase more rapidly, which will open a new route towards the ultrashort-time measurement. The proposed HHG method paves an efficient way for accessing the high-order fractional echoes in molecules.

Comparison of the ED50 and ED95 of Intrathecal Bupivacaine in Parturients Undergoing Cesarean Delivery With or Without Prophylactic Phenylephrine Infusion: A Prospective, Double-Blind Study.

BACKGROUND AND OBJECTIVES: While prophylactic phenylephrine infusions during cesarean delivery are often used to counteract the sympathectomy associated with spinal anesthesia, their use has been associated with decreased rostral spread of local anesthetic. The purpose of this study was to determine the median effective dose (ED50) and 95% effective dose (ED95) of intrathecal hyperbaric bupivacaine for cesarean delivery in the presence and absence of prophylactic phenylephrine infusion. METHODS: One hundred healthy parturients undergoing elective cesarean delivery under combined spinal-epidural anesthesia were enrolled in this randomized, double-blind, dose-finding study to determine ED50 and ED95. Subjects were randomly assigned to receive prophylactic phenylephrine or control (saline) infusion with injection of 6, 7.5, 9, 10.5, or 12 mg intrathecal hyperbaric bupivacaine. An effective dose was defined as achieving a T5 sensory level within 10 minutes of intrathecal drug administration without the need for epidural supplementation. RESULTS: The ED50 of intrathecal hyperbaric bupivacaine was 10.0 mg (95% confidence interval [CI], 5.9-11.4 mg) with prophylactic phenylephrine infusion and 7.9 mg (95% CI, 2.3-9.4 mg) in the control group. The ED95 of intrathecal hyperbaric bupivacaine was 14.1 mg (95% CI, 12.3-37.6 mg) with prophylactic phenylephrine infusion and 11.7 mg (95% CI, 9.9-22.8 mg) in the control group. CONCLUSIONS: The administration of prophylactic phenylephrine infusion results in higher intrathecal hyperbaric bupivacaine dosing requirements in parturients undergoing cesarean delivery. CLINICAL TRIAL REGISTRATION: This study was registered at the Chinese Clinical Trial Registry, identifier ChiCTR-TRC-16008938.

Single-shot molecular orbital tomography with orthogonal two-color fields.

Molecular orbital tomography (MOT) based on high-order-harmonic generation opens a way to track the molecular electron dynamics or even follow a chemical reaction. However, the real-time imaging of the evolution of electron orbitals is hampered by the multi-shot measurement of high-order harmonics. Here, we report a single-shot MOT scheme with orthogonal two-color (OTC) fields. This scheme enables the tomographic imaging of molecular orbital with single-shot measurement in experiment, owing to the two-dimensional manipulation of the electron motion in OTC fields. Our work paves the way towards tracking the molecular electron dynamics with combined attosecond temporal and sub-Ångström spatial resolutions.

[Design of a multifunctional and transparent urinary system model].

This article describes a novel Multifunctional and Transparent Urinary System Model (MTUSM), which can be applied to anatomy teaching, operational training of clinical skills as well as simulated experiments in vitro. This model covers kidneys, ureters, bladder, prostate, male and female urethra, bracket and pedestal, etc. Based on human anatomy structure and parameters, MTUSM consists of two transparent layers i. e. transparent organic glass external layer, which constraints the internal layer and maintains shape of the model, and transparent silica gel internal layer, which possesses perfect elasticity and deformability. It is obvious that this model is preferable in simulating the structure of human urinary system by applying hierarchical fabrication. Meanwhile, the transparent design, which makes the inner structure, internal operations and experiments visual, facilitates teaching instruction and understanding. With the advantages of simple making, high-findelity, unique structure and multiple functions, this model will have a broad application prospect and great practical value.

Arterial anastomosis without sutures using ring pin stapler for clinical renal transplantation: comparison with suture anastomosis.

PURPOSE: The metal ring pin stapler was initially developed for microvascular surgery and there has been little experience of their use in larger vessels. We determined if the titanium ring pin coupling system could be safely and rapidly applied for arterial reconstruction in clinical renal transplantation. MATERIALS AND METHODS: The donor renal artery was end-to-end anastomosed to the internal iliac artery with titanium ring pin staplers in 36 patients. Anastomotic, clamp and total operative time and vascular problems were compared with those in the control group of sutured anastomosis in 39 transplant recipients. RESULTS: The completion of mechanical anastomosis required half the time of suture anastomosis. Mean clamp time was 17.8 minutes in the nonsuture group and 28.1 minutes in the control group. There was no significant difference in total operative time between the 2 groups. A small anastomotic line leak was noted in each group, which was temporary and self-limited. There were no postoperative anastomotic failures, postoperative bleeding episodes or need to revise the anastomosis (100% patency rate) in the 2 groups. Of the patients 61 were followed for 2 to 5 years. Transplant renal artery stenosis was observed in 1 patient in the nonsuture group but 3 in the control group. CONCLUSIONS: The anastomotic technique with the ring pin system is safe and simple, permitting an expeditious and everting anastomosis with a smooth intima-to-intima junction. Application of this technique may decrease warm ischemia time and the incidence of anastomotic artery stenosis, thus, improving outcomes.

[Investigation of sexual function in male kidney transplant recipients].

OBJECTIVE: To observe the change of sexual function in male kidney transplant recipients. METHODS: Sixty married males, aged 26 to 45 years, who had received kidney transplantations at least half a year before and whose serum creatinine (Scr) was under 200 mumol/L, were selected randomly in the study. Sexual functions were reviewed before and after the patients' renal failure and after kidney transplantations. The results were analyzed in Chi-Square test methods. RESULTS: Their sexual functions, significantly aggravated after renal failure, were improved after kidney transplantations, but failed to return to normal. The recipients had a common worry that their sex lives might affect the renal grafts. CONCLUSIONS: Kidney transplantations significantly improve the sexual functions of these renal failure patients. It is quite necessary to provide sexological guidance to kidney transplant recipients and their spouses.