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2024年5月23日 · Visna-maedi virus. The human immunodeficiency viruses ( HIV) are two species of Lentivirus (a subgroup of retrovirus) that infect humans. Over time, they cause acquired immunodeficiency syndrome (AIDS), [1] [2] a condition in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive. [3]
4 天前 · Alzheimer's disease ( AD) is a neurodegenerative disease that usually starts slowly and progressively worsens, [2] and is the cause of 60–70% of cases of dementia. [2] [15] The most common early symptom is difficulty in remembering recent events. [1] As the disease advances, symptoms can include problems with language, disorientation ...
2 天前 · Hong Kong [d] is a special administrative region of the People's Republic of China. With 7.4 million residents of various nationalities [e] in a 1,104-square-kilometre (426 sq mi) territory, Hong Kong is one of the most densely populated territories in the world. Hong Kong was established as a colony of the British Empire after the Qing dynasty ...
1 天前 · t. e. The viscosity of a fluid is a measure of its resistance to deformation at a given rate. [1] For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water. [2] Viscosity is defined scientifically as a force multiplied by a time divided by an area.
3 天前 · George Washington (February 22, 1732 – December 14, 1799) was an American Founding Father, military officer, and politician who served as the first president of the United States from 1789 to 1797. Appointed by the Second Continental Congress as commander of the Continental Army in 1775, Washington led Patriot forces to victory in the American Revolutionary War and then served as president ...
1 天前 · e. The United States House of Representatives is the lower chamber of the United States Congress, with the Senate being the upper chamber. Together, they comprise the national bicameral legislature of the United States. [1] [2] The House is charged with the passage of federal legislation, known as bills; those that are also passed by the Senate ...
2024年5月23日 · Pearson correlation coefficient. Several sets of ( x , y) points, with the correlation coefficient of x and y for each set. The correlation reflects the strength and direction of a linear relationship (top row), but not the slope of that relationship (middle), nor many aspects of nonlinear relationships (bottom).
