Systole

Systole /ˈsɪstəliː/ is the part of the cardiac cycle when the ventricles contract. The term "systole" originates from New Latin, from Ancient Greek συστολή (sustolē), from συστέλλειν (sustellein, "to contract"), from σύν (syn, "together") + στέλλειν (stellein, "send").

The mammalian heart has 4 chambers: the left atrium, the left ventricle, the right atrium and the right ventricle.

When the smaller, upper atria chambers contract in late diastole, they send blood down to the larger, lower ventricle chambers. When the lower chambers are filled and the valves to the atria are closed, the ventricles undergo isovolumetric contraction (contraction of the ventricles while all valves are closed), marking the first stage of systole. The second phase of systole sends blood from the left ventricle to the aorta and body extremities, and from the right ventricle to the lungs. Thus, the atria and ventricles contract in alternating sequence. The left and right atria feed blood, at the same time, into the ventricles. Then, the left and right ventricles contract simultaneously as well.

Medicine

Medicine (British English ⁱ/ˈmɛdsᵻn/; American English ⁱ/ˈmɛdᵻsᵻn/) is the science and practice of the diagnosis, treatment, and prevention of disease. The word medicine is derived from Latin medicus, meaning "a physician". Medicine encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness.

Contemporary medicine applies biomedical sciences, biomedical research, genetics, and medical technology to diagnose, treat, and prevent injury and disease, typically through pharmaceuticals or surgery, but also through therapies as diverse as psychotherapy, external splints and traction, medical devices, biologics, and ionizing radiation, amongst others.

Medicine has existed for thousands of years, during most of which it was an art (an area of skill and knowledge) frequently having connections to the religious and philosophical beliefs of local culture. For example, a medicine man would apply herbs and say prayers for healing, or an ancient philosopher and physician would apply bloodletting according to the theories of humorism. In recent centuries, since the advent of science, most medicine has become a combination of art and science (both basic and applied, under the umbrella of medical science). While stitching technique for sutures is an art learned through practice, the knowledge of what happens at the cellular and molecular level in the tissues being stitched arises through science.

Medicine (Lippincott Williams & Wilkins journal)

Medicine is an open access peer-reviewed medical journal published by Lippincott Williams & Wilkins. It was established in 1922. Of general medical journals still in publication since 1959, Medicine had the highest number of citations per paper between 1959 and 2009. The journal covers all aspects of clinical medicine. On March 31, 2014 Medicine changed into an open access publication, publishing in a broad spectrum of medical specialties.

Abstracting and indexing

The journal is abstracted and indexed in:

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History of medicine

This article deals with medicine as practiced by trained professionals from ancient times to the present. Early medical traditions include those of Babylon, China, Egypt and India. The Greeks went even further, introducing the concepts of medical diagnosis, prognosis, and advanced medical ethics. The Hippocratic Oath, still taken (although significantly changed from the original) by doctors up to today, was written in Greece in the 5th century BCE. In the medieval age, surgical practices inherited from the ancient masters were improved and then systematized in Rogerius's The Practice of Surgery. Universities began systematic training of physicians around the years 1220 in Italy. During the Renaissance, understanding of anatomy improved, and the microscope was invented. The germ theory of disease in the 19th century led to cures for many infectious diseases. Military doctors advanced the methods of trauma treatment and surgery. Public health measures were developed especially in the 19th century as the rapid growth of cities required systematic sanitary measures. Advanced research centers opened in the early 20th century, often connected with major hospitals. The mid-20th century was characterized by new biological treatments, such as antibiotics. These advancements, along with developments in chemistry, genetics, and lab technology (such as the x-ray) led to modern medicine. Medicine was heavily professionalized in the 20th century, and new careers opened to women as nurses (from the 1870s) and as physicians (especially after 1970). The 21st century is characterized by highly advanced research involving numerous fields of science.

Systolic geometry

In mathematics, systolic geometry is the study of systolic invariants of manifolds and polyhedra, as initially conceived by Charles Loewner and developed by Mikhail Gromov, Michael Freedman, Peter Sarnak, Mikhail Katz, Larry Guth, and others, in its arithmetical, ergodic, and topological manifestations. See also a slower-paced Introduction to systolic geometry.

The notion of systole

The systole of a compact metric space X is a metric invariant of X, defined to be the least length of a noncontractible loop in X (i.e. a loop that cannot be contracted to a point in the ambient space X). In more technical language, we minimize length over free loops representing nontrivial conjugacy classes in the fundamental group of X. When X is a graph, the invariant is usually referred to as the girth, ever since the 1947 article on girth by W. T. Tutte. Possibly inspired by Tutte's article, Loewner started thinking about systolic questions on surfaces in the late 1940s, resulting in a 1950 thesis by his student Pao Ming Pu. The actual term "systole" itself was not coined until a quarter century later, by Marcel Berger.

Ploetzia

Ploetzia is a genus of skippers in the family Hesperiidae. It consists of only one species, Ploetzia amygdalis, which is found in northern and north-eastern Madagascar. The habitat consists of forests and anthropogenic environments.

The larvae feed on the leaves of Coconut palms of the Arecaceae family.

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