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Displaying 1401 - 1416 of 1416 items.

Peter Mazur (1928–2015)

Peter Mazur was a researcher in the US who developed new ways of preserving biological material by freezing it, a process called cryopreservation. If done correctly, cryopreservation enables scientists to store or study biological material for an extended period of time. If done incorrectly, cryopreservation can easily harm or destroy biological material. Mazur worked to find the best ways to cryopreserve different cells, embryos, and organs in order to minimize the damage caused by freezing.

Format: Articles

Subject: People

George McDonald Church (1954- )

George McDonald Church studied DNA from living and from extinct species in the US during the twentieth and twenty-first centuries. Church helped to develop and refine techniques with which to describe the complete sequence of all the DNA nucleotides in an organism's genome, techniques such as multiplex sequencing, polony sequencing, and nanopore sequencing. Church also contributed to the Human Genome Project, and in 2005 he helped start a company, the Personal Genome Project. Church proposed to use DNA from extinct species to clone and breed new organisms from those species.

Format: Articles

Subject: People, Technologies

Franz Max Albert Kramer (1878–1967)

Scientist Franz Max Albert Kramer worked as a psychiatrist in Poland and the Netherlands in the early twentieth century and is known for his contributions to research on psychological conditions that experts call hyperkinetic syndromes. Children with hyperkinetic syndromes display inattention, overactivity, and impulsivity. Along with scientist Hans Pollnow, Kramer defined a specific kind of hyperkinetic syndrome based on an initial case study of seventeen children, initially known as Kramer-Pollnow Syndrome.

Format: Articles

Subject: People

Michael R. Harrison (1943– )

Michael R. Harrison worked as a pediatric surgeon in the US throughout the late-twentieth century and performed many fetal surgeries, including one of the first successful surgeries on a fetus in utero, or while it is still in its gestational carrier’s body, also called open fetal surgery. A fetus is an organism developing inside of the uterus that is anywhere from eight weeks old to birth. Harrison hypothesized that open fetal surgery could correct developmental defects that may become fatal to the fetus at birth.

Format: Articles

Subject: People

Mary Coffin Ware Dennett (1872-1947)

Mary Coffin Ware Dennett advocated for social reform in the United States in the early twentieth century, particularly regarding sex education and women's rights to access contraception. Dennett authored several publications on sex education and birth control laws. She also worked to repeal the Comstock Act, a federal law that made it illegal to distribute obscene materials through the US Postal Services.

Format: Articles

Subject: People, Reproduction

Joseph Bolivar DeLee (1869–1942)

Joseph Bolivar DeLee was an obstetrician in the US between the nineteenth and twentieth centuries who advocated for the specialized teaching of medical students in the field of obstetrics to address problems occurring during pregnancy. He claimed obstetricians maintained a wider skillset than midwives, and founded the Chicago Lying-In Hospital to provide affordable obstetric care to women in Chicago, Illinois.

Format: Articles

Subject: People

Walter Schiller (1887–1960)

Walter Schiller studied the causes of diseases in the US and Austria in the early twentieth century and in 1928, invented the Schiller test, or a way to diagnose early cervical cancer in women. Cervical cancer is the uncontrollable division of cells in the cervix, or lower part of the uterus. While living in Austria until his emigration to escape the Nazis in 1937, Schiller concluded that there was a form of cervical cancer, later named carcinoma in situ, that physicians could detect earlier than when tumors start to appear.

Format: Articles

Subject: People

Virginia Apgar (1909–1974)

Virginia Apgar worked as an obstetrical anesthesiologist, administering drugs that reduce women’s pain during childbirth, in the US in the mid-twentieth century. In 1953, Apgar created a scoring system using five easily assessable measurements, including heart rate and breathing rate, to evaluate whether or not infants would benefit from medical attention immediately after birth. Apgar’s system showed that infants who were previously set aside as too sick to survive, despite low Apgar scores, could recover with immediate medical attention.

Format: Articles

Subject: People, Reproduction

Virginia Apgar (1909–1974)

During the mid-twentieth century, Virginia Apgar worked as an obstetrical anesthesiologist and gave drugs to women that reduced their pain during childbirth in the US. In 1953, Apgar created a scoring system, called the Apgar score, that uses five measurements, including heart rate and breathing rate. The Apgar score evaluates newborn infants and determines who needs immediate medical attention. Apgar's work helped decrease infant mortality rates. As of 2020, hospitals around the world use the Apgar score.

Format: Graphics

Subject: People

Jérôme Lejeune (1926−1994)

Jérôme Lejeune was a French physician and researcher who studied genetics and developmental disorders. According to the Jérôme Lejeune Foundation, in 1958, Lejeune discovered that the existence of an extra twenty-first chromosome, a condition called Trisomy 21, causes Down Syndrome. Down Syndrome is a condition present in an individual since birth and is characterized by physical and developmental anomalies such as small ears, a short neck, heart defects, and short height as children and adults.

Format: Articles

Subject: People

Johann Gregor Mendel (1822–1884)

Johann Gregor Mendel studied patterns of trait inheritance in plants during the nineteenth century. Mendel, an Augustinian monk, conducted experiments on pea plants at St. Thomas’ Abbey in what is now Brno, Czech Republic. Twentieth century scientists used Mendel’s recorded observations to create theories about genetics.

Format: Graphics

Subject: People

Johann Gregor Mendel (1822-1884)

Johann Gregor Mendel studied plants and their patterns of inheritance in Austria during the nineteenth century. Mendel experimented with the pea plant, Pisum, and his publication, 'Versuche uber Pflanzenhybriden' (“Experiments on Plant Hybridization”), published in 1866, revolutionized theories of trait inheritance. Mendel’s discoveries relating to factors, traits, and how they pass between generations of organisms enabled scientists in the twentieth century to build theories of genetics.

Format: Articles

Subject: People

John Langdon Down (1828–1896)

John Langdon Down studied medicine in England in the nineteenth century and was one of the first people to develop a complete description of the disorder that would later be known as Trisomy 21, or Down Syndrome. Down Syndrome is a condition caused by the presence of an extra chromosome, which may cause a person to be born with certain impaired learning abilities and physical features such as a short neck, flattened face, and almond-shaped eyes.

Format: Articles

Subject: People

Roger Wolcott Sperry (1913–1994)

Roger Wolcott Sperry studied the function of the nervous system in the US during the twentieth century. He studied split-brain patterns in cats and humans that result from separating the two hemispheres of the brain by cutting the corpus callosum, the bridge between the two hemispheres of the brain. He found that separating the corpus callosum the two hemispheres of the brain could not communicate and they performed functions as if the other hemisphere did not exist. Sperry studied optic nerve regeneration through which he developed the chemoaffinity hypothesis.

Format: Articles

Subject: People

George Otto Gey (1899-1970)

George Otto Gey was a scientist in the US who studied cells and cultivated the first continuous human cell line in 1951. Gey derived the cells for that cell line, called the HeLa cell line, from a woman called Henrietta Lacks, a Black woman who had cervical cancer. Cell lines are a cluster of cells that continuously multiply on their own outside of the organism from which they originated. Gey developed new techniques for in vitro, or laboratory-based, maintenance of organs and hormonal tissue, created new methods for cell cultivation, and researched nutritional media, or cell food.

Format: Articles

Subject: People

Beatrice Mintz (1922–2022)

Beatrice Mintz is a brilliant researcher who has developed techniques essential for many aspects of research on mouse development. She produced the first successful mouse chimeras and meticulously characterized their traits. She has worked with various cancers and produced viable mice from the cells of a teratoma. Mintz participated in the development of transgenic mice by the incorporation of foreign DNA into a mouse genome.

Format: Articles

Subject: People