A Systematic Review of Electrocardiographic Changes in Populations Temporarily Ascending to High Altitudes.

High altitudes can cause hypobaric hypoxia, altering human physiology and the corresponding electrocardiogram (ECG). As part of the Altitude Nondifferentiated ECG Study (ANDES), this paper reviews ECG changes in subjects ascending to high altitudes. This review was conducted following PRISMA guidelines.

On Maurício M. Peixoto and the arrival of Structural Stability to Rio de Janeiro, 1955.

This essay is a historical exploration of the circumstances, and subsequent mathematical consequences, of the encounter, in 1955, of Maurício M. Peixoto (1921 - 2019) with the work of Henry F. DeBaggis (1916 - 2002) on Structural Stability, Princeton 1952, developing a notion introduced by Alexander A.

[Epidemiological characteristics of ST-segment elevation myocardial infarction in Peru: Results of the PEruvian Registry of ST-segment Elevation Myocardial Infarction (PERSTEMI)].

Objective: To determine the epidemiological characteristics, treatment, reperfusion strategies and in-hospital adverse events of patients with ST elevation myocardial infarction in Peru.

Methods: Observational, prospective multicentre study in patients over 18 years admitted to hospital with a diagnosis of ST elevation myocardial infarction.

Results: A total of 396 patients were enrolled in the registry during February 2016 to February 2017.

Lines of principal curvature on canal surfaces in R3.

In this paper are determined the principal curvatures and principal curvature lines on canal surfaces which are the envelopes of families of spheres with variable radius and centers moving along a closed regular curve in R3. By means of a connection of the differential equations for these curvature lines and real Riccati equations, it is established that canal surfaces have at most two isolated periodic principal lines. Examples of canal surfaces with two simple and one double periodic principal lines are given.