Catechol estrogenA catechol estrogen is a steroidal estrogen that contains catechol (1,2-dihydroxybenzene) within its structure. The catechol estrogens are endogenous metabolites of estradiol and estrone and include the following compounds: 2-Hydroxylated: 2-Hydroxyestradiol 2-Hydroxyestrone 2-Hydroxyestriol 4-Hydroxylated: 4-Hydroxyestradiol 4-Hydroxyestrone 4-Hydroxyestriol The most abundant catechol estrogen in serum and urine is 2-hydroxyestrone, with 2-hydroxyestradiol and 2-hydroxyestriol also being formed, while the principal 4-hydroxy catechol estrogen, 4-hydroxyestrone, is present in only small amounts in urine.
ColluviumColluvium (also colluvial material or colluvial soil) is a general name for loose, unconsolidated sediments that have been deposited at the base of hillslopes by either rainwash, sheetwash, slow continuous downslope creep, or a variable combination of these processes. Colluvium is typically composed of a heterogeneous range of rock types and sediments ranging from silt to rock fragments of various sizes. This term is also used to specifically refer to sediment deposited at the base of a hillslope by unconcentrated surface runoff or sheet erosion.
2-Hydroxyestrone2-Hydroxyestrone (2-OHE1), also known as estra-1,3,5(10)-trien-2,3-diol-17-one, is an endogenous, naturally occurring catechol estrogen and a major metabolite of estrone and estradiol. It is formed irreversibly from estrone in the liver and to a lesser extent in other tissues via 2-hydroxylation mediated by cytochrome P450 enzymes, mainly the CYP3A and CYP1A subfamilies. 2-OHE1 is the most abundant catechol estrogen in the body.
Estrogen (medication)An estrogen (E) is a type of medication which is used most commonly in hormonal birth control and menopausal hormone therapy, and as part of feminizing hormone therapy for transgender women. They can also be used in the treatment of hormone-sensitive cancers like breast cancer and prostate cancer and for various other indications. Estrogens are used alone or in combination with progestogens. They are available in a wide variety of formulations and for use by many different routes of administration.
Conjugated estrogensConjugated estrogens (CEs), or conjugated equine estrogens (CEEs), sold under the brand name Premarin among others, is an estrogen medication which is used in menopausal hormone therapy and for various other indications. It is a mixture of the sodium salts of estrogen conjugates found in horses, such as estrone sulfate and equilin sulfate. CEEs are available in the form of both natural preparations manufactured from the urine of pregnant mares and fully synthetic replications of the natural preparations.
Water extractionWater extraction (or water withdrawal) is the process of taking water from any source, either temporarily or permanently, for flood control or to obtain water for, for example, irrigation. The extracted water could also be used as drinking water after suitable treatment. Depending on the environmental legislation in the country, controls may be placed on extraction to limit the amount of water that can be removed. The over-extraction of water can lead to dry rivers or declining groundwater levels.
Estrone (medication)Estrone (E1), sold under the brand names Estragyn, Kestrin, and Theelin among many others, is an estrogen medication and naturally occurring steroid hormone which has been used in menopausal hormone therapy and for other indications. It has been provided as an aqueous suspension or oil solution given by injection into muscle and as a vaginal cream applied inside of the vagina. It can also be taken by mouth as estradiol/estrone/estriol (brand name Hormonin) and in the form of prodrugs like estropipate (estrone sulfate; brand name Ogen) and conjugated estrogens (mostly estrone sulfate; brand name Premarin).
3β-Androstanediol3β-Androstanediol, also known as 5α-androstane-3β,17β-diol, and sometimes shortened in the literature to 3β-diol, is an endogenous steroid hormone and a metabolite of androgens like dehydroepiandrosterone (DHEA) and dihydrotestosterone (DHT). 3β-Androstanediol is a selective, high-affinity agonist of the ERβ, and hence, an estrogen. In contrast to ERβ, 3β-androstanediol does not bind to the androgen receptor (AR). 3β-Androstanediol has been reported to also bind to ERα with low nanomolar affinity, with several-fold lower affinity relative to ERβ.
ToremifeneToremifene, sold under the brand name Fareston among others, is a medication which is used in the treatment of advanced breast cancer in postmenopausal women. It is taken by mouth. Side effects of toremifene include hot flashes, sweating, nausea, vomiting, dizziness, vaginal discharge, and vaginal bleeding. It can also cause blood clots, irregular heartbeat, cataracts, visual disturbances, elevated liver enzymes, endometrial hyperplasia, and endometrial cancer. High blood calcium levels can occur in women with bone metastases.
Yellow RiverThe Yellow River is the second-longest river in China, after the Yangtze River, and the sixth-longest river system in Earth at the estimated length of . Originating at an elevation above 15,000 feet (4,600 metres) in the Bayan Har Mountains, it empties into the Bohai Sea. The Yellow River's basin was the birthplace of several ancient civilizations. The yellow sediments were carried downstream from the Loess Plateau. There are frequent devastating floods and course changes produced by the continual elevation of the river bed, sometimes above the level of its surrounding farm fields.
