Atrial Fibrillation in the Arab World: A Bibliometric Analysis of Research Activity from 2004 to 2019

Background: Atrial fibrillation (AF) is in an increasing pattern worldwide, especially in the Arab world. Objective: The aim of this article is to assess AF research activity in the Arab countries over the past 16 years, taking into consideration the population size, gross domestic product (GDP) and disability-adjusted life years (DALY). Methods: Atrial fibrillation related research articles published from Arab countries between 2004 and 2019 were collected from the MEDLINE database and are cited online on PubMed. Medical Subject Heading (MeSH) terms related to the subject, the origin and the date of publication were used to search for the published articles. Results: The number of AF related publications in the Arab world over the past 16 years was only 283 (0.73%) out of a total of 38,983 publications worldwide. Saudi Arabia ranked first in terms of number of AF related publications, followed by Egypt. Lebanon is the country with the highest number of publications per USD billion GDP, while Egypt and Saudi Arabia have the highest number of publications per 1% DALYs. According to the population size, Qatar and Bahrain produced the highest number of publications per million persons (PPMP). A strong and positive correlation was found between the number of publications and the GDP. The population size and the percentage of DALY showed positive yet weak correlation. Conclusion: A slight increase in AF related publications is observed. Nonetheless, AF research activity in the Arab world is still insufficient

Atrial Fibrillation in the Arab World: A Bibliometric Analysis of Research Activity from 2004 to 2019

Background: Atrial fibrillation (AF) is in an increasing pattern worldwide, especially in the Arab world. Objective: The aim of this article is to assess AF research activity in the Arab countries over the past 16 years, taking into consideration the population size, gross domestic product (GDP) and disability-adjusted life years (DALY). Methods: Atrial fibrillation related research articles published from Arab countries between 2004 and 2019 were collected from the MEDLINE database and are cited online on PubMed. Medical Subject Heading (MeSH) terms related to the subject, the origin and the date of publication were used to search for the published articles. Results: The number of AF related publications in the Arab world over the past 16 years was only 283 (0.73%) out of a total of 38,983 publications worldwide. Saudi Arabia ranked first in terms of number of AF related publications, followed by Egypt. Lebanon is the country with the highest number of publications per USD billion GDP, while Egypt and Saudi Arabia have the highest number of publications per 1% DALYs. According to the population size, Qatar and Bahrain produced the highest number of publications per million persons (PPMP). A strong and positive correlation was found between the number of publications and the GDP. The population size and the percentage of DALY showed positive yet weak correlation. Conclusion: A slight increase in AF related publications is observed. Nonetheless, AF research activity in the Arab world is still insufficient

The fine structure of the terminal branches of the hepatic arterial system of the rat Supported by a grant from the Faculty Research Fund, Horace H. Rackham School of Graduate Studies, The University of Michigan.

The fine structure of the smallest branches of the hepatic arterial system of the rat was studied with the light and electron microscope by means of alternate thick and thin serial sections. The terminal arborizations of the hepatic artery closely follow the pattern of the portal vein and give rise to a dense network of capillaries in the periportal connective tissue which closely surrounds the bile ducts. These periductal capillaries end by joining (a) interlobular veins, (b) terminal distributing veins, (c) sinusoids directly or, (d) sinusoids in common with branches of the portal vein. The capillaries arising from larger arterioles have well developed precapillary sphincters at their origins, while those arising from terminal arterioles have less prominent smooth muscle cuffs. There are no smooth muscle sphincters at the terminal ends of the capillaries where they join branches of the portal vein or sinusoids. Large endothelial cells usually guard these junctions and frequently their nuclei bulge into the lumens of the vessels and may close them off. Occasionally unmyelinated nerves with vesicles about 500 Å in diameter, some of which are granulated, are in close proximity to the endothelial cells of the capillaries. Endothelial cells also guard the beginnings of sinusoids originating from the portal vein. The sinusoids arising from periductal capillaries are identical in structure to those directly off from the portal vein. Initially the sinusoids from both types of vessels are like capillaries, with a continuous basement membrane around them and an unfenestrated endothelium. A short distance into the parenchyma they lose their basement membrane, become fenestrated and are typical sinusoids.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/49820/1/1091670307_ftp.pd