Article by hi joiney

Synthesis Bisphenol A was first reported by A P Dianin in 1891 It is prepared by the condensation of acetone hence the suffix A in the name with two equivalents of phenol The reaction is catalyzed by an acid such as hydrochloric acid HCl or a sulfonated polystyrene resin Typically a large excess of phenol is used to ensure full condensation CH3 2CO 2 C6H5OH CH3 2C C6H4OH 2 H2O A large number of ketones undergo analogous condensation reactions The method is efficient and the only by product is water Use Further information Polycarbonate Repeating chemical structure unit of polycarbonate made from bisphenol A Bisphenol A is used primarily to make plastics and products containing bisphenol A based plastics have been in commerce for more than 50 years It is a key monomer in production of epoxy resins and in the most common form of polycarbonate plastic Polycarbonate plastic which is clear and nearly shatter proof is used to make a variety of common products including baby and water bottles sports equipment medical and dental devices dental fillings and sealants eyeglass lenses CDs and DVDs and household electronics BPA is also used in the synthesis of polysulfones and polyether ketones as an antioxidant in some plasticizers and as a polymerization inhibitor in PVC Epoxy resins containing bisphenol A are used as coatings on the inside of almost all food and beverage cans however due to BPA health concerns in Japan epoxy coating was mostly replaced by PET film Bisphenol A is also a precursor to the flame retardant tetrabromobisphenol A and was formerly used as a fungicide Bisphenol A is a preferred color developer in thermal paper and in carbonless copy paper Global production of bisphenol A in 2003 was estimated to be over 2 million tonnes In the U S it is manufactured by Bayer MaterialScience Dow Chemical Company SABIC Innovative Plastics formerly GE Plastics Hexion Specialty Chemicals and Sunoco Chemicals In 2004 these companies produced just over 1 million t of bisphenol A up from just 7 260 t in 1991 In 2003 annual U S consumption was 856 000 t 72 of which was used to make polycarbonate plastic and 21 going into epoxy resins Identification in plastics Main article Resin identification code Some type 7 plastics may leach bisphenol A Some type 3 plastics may leach bisphenol A There are seven classes of plastics used in packaging applications Type 7 is the catch all other class and some type 7 plastics such as polycarbonate sometimes identified with the letters PC near the recycling symbol and epoxy resins are made from bisphenol A monomer Type 3 PVC can also contain bisphenol A as an antioxidant in plasticizers Types 1 PET 2 HDPE 4 LDPE 5 polypropylene and 6 polystyrene do not use bisphenol A during polymerization or package forming citation needed Health effects Bisphenol A is an endocrine disruptor which can mimic the body s own hormones and may lead to negative health effects Early development appears to be the period of greatest sensitivity to its effects Regulatory bodies have determined safety levels for humans but those safety levels are currently being questioned or under review as a result of new scientific studies In 2009 the The Endocrine Society released a scientific statement expressing concern over current human exposure to BPA Previous studies In 2007 a consensus statement by 38 experts on bisphenol A concluded that average levels in people are above those that cause harm to animals in laboratory experiments A panel convened by the U S National Institutes of Health determined that there was some concern about BPA s effects on fetal and infant brain development and behavior A 2008 report by the U S National Toxicology Program NTP later agreed with the panel expressing some concern for effects on the brain behavior and prostate gland in fetuses infants and children at current human exposures to bisphenol A and minimal concern for effects on the mammary gland and an earlier age for puberty for females in fetuses infants and children at current human exposures to bisphenol A The NTP had negligible concern that exposure of pregnant women to bisphenol A will result in fetal or neonatal mortality birth defects or reduced birth weight and growth in their offspring Obesity A 2008 review has concluded that obesity may be increased as a function of BPA exposure which merits concern among scientists and public health officials A 2009 review of available studies has concluded that perinatal BPA exposure acts to exert persistent effects on body weight and adiposity Another 2009 review has concluded that Eliminating exposures to BPA and improving nutrition during development offer the potential for reducing obesity and associated diseases Other reviews have come with similar conclusions A later study on rats has suggested that perinatal exposure to drinking water containing 1 160 mg L of BPA increased adipogenesis in females at weaning Neurological issues A panel convened by the U S National Institutes of Health determined that there was some concern about BPA s effects on fetal and infant brain development and behavior A 2008 report by the U S National Toxicology Program NTP later agreed with the panel expressing some concern for effects on the brain In January 2010 the FDA expressed the same level of concern A 2007 review has concluded that BPA like other xenoestrogens should be considered as a player within the nervous system that can regulate or alter its functions through multiple pathways A 2007 review has concluded that low doses of BPA during development have persistent effects on brain structure function and behavior in rats and mice A 2008 review concluded that low dose BPA maternal exposure causes long term consequences at the level of neurobehavioral development in mice A 2008 review has concluded that neonatal exposure to Bisphenol A BPA can affect sexually dimorphic brain morphology and neuronal phenotypes in adulthood A 2008 review has concluded that BPA altered long term potentiation in the hippocampus and even nanomolar dosage could induce significant effects on memory processes A 2009 review raised concerns about BPA effect on anteroventral periventricular nucleus A 2008 study by the Yale School of Medicine demonstrated that adverse neurological effects occur in non human primates regularly exposed to bisphenol A at levels equal to the United States Environmental Protection Agency s EPA maximum safe dose of 50 160 g kg day This research found a connection between BPA and interference with brain cell connections vital to memory learning and mood Highly controversial claims have been made that BPA could be involved in attention deficit hyperactivity disorder ADHD Disruption of the dopaminergic system A 2005 review concluded that prenatal and neonatal exposure to BPA in mice can potentiate the central dopaminergic systems resulting in the supersensitivity to the drugs of abuse induced reward effects and hyperlocomotion A 2008 review has concluded that BPA mimic estrogenic activity and impact various dopaminergic processes to enhance mesolimbic dopamine activity resulting in hyperactivity attention deficits and a heightened sensitivity to drugs of abuse A 2009 study on rats has concluded that prenatal and neonatal exposure to low dose BPA causes deficits in development at dorsolateral striatum via altering the function of dopaminergic receptors Another 2009 study has found associated changes in the dopaminergic system Thyroid function A 2007 review has concluded that bisphenol A have been shown to bind to thyroid hormone receptor and perhaps have selective effects on its functions A 2009 review about environmental chemicals and thyroid function raised concerns about BPA effects on triiodothyronine and concluded that available evidence suggests that governing agencies need to regulate the use of thyroid disrupting chemicals particularly as such uses relate exposures of pregnant women neonates and small children to the agents A 2009 review summarized BPA adverse effects on thyroid hormone action Cancer research According to the WHO s INFOSAN animal studies have not provided convincing evidence of risk of cancer from BPA exposure Neither the U S Environmental Protection Agency nor the International Agency for Research on Cancer has evaluated bisphenol A for possible carcinogenic activity Breast cancer Further information Risk factors of breast cancer Bisphenol A A 2008 review has concluded that perinatal exposure to low doses of BPA alters breast development and increases breast cancer risk Another 2008 review concluded that animal experiments and epidemiological data strengthen the hypothesis that foetal exposure to xenoestrogens may be an underlying cause of the increased incidence of breast cancer observed over the last 50 years A 2009 in vitro study has concluded that BPA is able to induce neoplastic transformation in human breast epithelial cells Another 2009 study concluded that maternal oral exposure to low concentrations of BPA during lactation increases mammary carcinogenesis in a rodent model Neuroblastoma In vitro studies have suggested that BPA can promote the growth of neuroblastoma cells A 2010 in vitro study has concluded that BPA potently promote invasion and metastasis of neuroblastoma cells through overexpression of MMP 2 and MMP 9 as well as downregulation of TIMP2 Prostate development and cancer A 1997 study in mice has found that neonatal BPA exposure of 2 g kg increased adult prostate weight A 2005 study in mice has found that neonatal BPA exposure at 10 g kg disrupted the development of the fetal mouse prostate A 2006 study in rats has shown that neonatal bisphenol A exposure at 10 g kg levels increases prostate gland susceptibility to adult onset precancerous lesions and hormonal carcinogenesis A 2007 in vitro study has found that BPA within the range of concentrations currently measured in human serum is associated with permanently increase in prostate size A 2009 study has found that newborn rats exposed to a low dose of BPA 10 g kg increased prostate cancer susceptibility when adults Reproductive system and sexual behavior research A series of studies made in 2009 found Mouse ovary anomalies from exposition as low as 1 160 g kg concluded that BPA exposure causes long term adverse reproductive and carcinogenic effects if exposure occurs during prenatal critical periods of differentiation Neonatal exposure of as low as 50 160 g kg disrupts ovarian development in mice Neonatal BPA exposition of as low as 50 160 g kg permanently alters the hypothalamic estrogen dependent mechanisms that govern sexual behavior in the adult female rat Prenatal exposure to BPA at levels of 10 g kg day affects behavioral sexual differentiation in male monkeys In placental JEG3 cells in vitro BPA may reduce estrogen synthesis BPA exposure disrupted the blood testis barrier when administered to immature but not to adult rats Exposure to BPA in the workplace could produce sexual dysfunction in male adult humans General research In 2009 at an Endocrine Society meeting new research reported data from animals experimentally treated with BPA Studies presented at the group s annual meeting show BPA can affect the hearts of women can permanently damage the DNA of mice and appear to be entering the human body from a variety of unknown sources A 2009 in vitro study on cytotrophoblasts cells has found cytoxic effects in exposure of BPA doses from 0 0002 to 0 2 micrograms per millilitre and concluded this finding suggests that exposure of placental cells to low doses of BPA may cause detrimental effects leading in vivo to adverse pregnancy outcomes such as preeclampsia intrauterine growth restriction prematurity and pregnancy loss A 2009 study in rats concluded that BPA at the reference safe limit for human exposure was found to impact intestinal permeability and may represent a risk factor in female offspring for developing severe colonic inflammation in adulthood A 2010 study on mice has concluded that perinatal exposure to 10 micrograms mL of BPA in drinking water enhances allergic sensitization and bronchial inflammation and responsiveness in an animal model of asthma Studies on humans Lang study and heart disease The first large study of health effects on humans associated with bisphenol A exposure was published in September 2008 by Iain Lang and colleagues in the Journal of the American Medical Association The cross sectional study of almost 1 500 people assessed exposure to bisphenol A by looking at levels of the chemical in urine The authors found that higher bisphenol A levels were significantly associated with heart disease diabetes and abnormally high levels of certain liver enzymes An editorial in the same issue notes that while this preliminary study needs to be confirmed and cannot prove causality there is precedent for analogous effects in animal studies which add s biological plausibility to the results reported by Lang et al A later similar study performed by the same group of scientists published in January 2010 confirmed despite of lower concentrations of BPA in the second study sample an associated increased risk for heart disease but not for diabetes or liver enzymes Other studies Studies have associated recurrent miscarriage with BPA serum concentrations oxidative stress and inflamattion in postmenopausal women with urinary concentrations externalizing behaviors in two year old children especially among female children with mother s urinary concentrations and altered hormone levels in men with urinary concentrations Historical studies The first evidence of the estrogenicity of bisphenol A came from experiments on rats conducted in the 1930s but it was not until 1997 that adverse effects of low dose exposure on laboratory animals were first reported Low dose exposure in animals Dose g kg day Effects measured in studies of mice or rats descriptions in quotes are from Environmental Working Group Study Year 0 025 Pe

Related Mosaic Stone Adhd Articles

Article by hello manty

rosetta stone levels their security and a touch of home along with them. Next, you need to look at a bed bug steamer that comes with extraction capabilities. It has been her constant companion since she was therosetta stone levels ripe old age of six weeks old and has calmed her through hurt feelings, nightmares, and new houses, along with fights with her brother and scolds from mother and dad.So what functions ought to your screen, desk, keyboard, mouse and chair need to keep you feeling great?Your keep track of ought to:- swivel, tilt and elevate- fit an extra adjustable stand to adjust the height if require be.you numerous choices when unwinding. Most places will not custom make every single meal. Even though canister types are lighter, they require picking up to move around. This provides slightly more quiet time in which the princesses can steady and the craft table may be cleaned up to prepare for the cake, ice cream, and presents later on. For refurbishing your interiors the first and foremost thing which should be kept in mind is the requirement of the area which is to be tiled up. Stone elements generally add great contrast to a garden.Decorations ought to be rather simple, pink and lavender or green streamers are fantastic for the style and confetti followed with plates, cups, and napkins in a color that is appropriate for the party theme (if there’s a particular princess being honored) are a fantastic beginning and youngsters truly don’t need significantly more decoration than that unless naturally you’ve a princess that has a gentle spot for balloons. A person with ADD or ADHD may be different, but that doesn?t have to be a bad thing or something that defines your child. Week 16 talks about being specific when you talk to your child about their behavior.? It’s a unique experience that is something that can’t be ignored. You have to adjust your budget depending on the size of the spa, the bigger it is, the more expensive it will be. Make small targets of taking out ten minutes from your busy work schedule to put one thing in order at a time and organize your office.

new: If you’ve got a fuel or wood fireplace, you might have believed about converting it to a pellet stove. For this reason, you need to provide garage doors parts in the right type. The cold weather months make it challenging for wild birds to discover food.Remember, if you keep your A/C unit properly maintained annually and keep your filters nice and clean, you can expect a long life of cooling from your Air Conditioning unit. With numerous choices accessible, consider just how much space you’re willing to give over to your waterfall. Not only will they be able to find the blockage or damage in your drain but they will also be able to see the problem, therefore they will be able to make the right recommendations for fixing it. But did you ever consider that crawlspace encapsulation could bring down those high electricity bills? As noted above, when your crawlspace is left open to breathe, it sends air up into your home. Mosaic tiles are extremely rich when it comes to designs and colors, but they are equally efficient in strength. Change the water each and every fo Is the installing all over the house or in a single room in your home? It really is much easier to match grain patterns, movement, coloring, and finish when utilizing unfinished planks. A very important yet often overlooked part of the sink is the faucet; you should refrain from sparing any type of money on customized faucets because not only are they not very expensive, but yet if done right they can add tremendous artistic value to the whole picture. If you are utilizing them for a patio they additionally help to make

More Mosaic Stone Adhd Articles