czwartek, 24 stycznia 2019
zamknij [x]
do:

Chemia/Biochemia (899)

123
567... z 45

Zdjęcia

! EN_01178034_0005 SCI
Carbonyl iron powder (CIP), coloured scanning electron micrograph (SEM). This fine spherical powder is produced by the thermal decomposition of iron pentacarbonyl. It has a number of applications, including the production of diamond tools, microwave and radar absorbing materials, magnetic inks and in nutritional supplements. Magnification: 10,000 when printed at 10 centimetres wide.
EN_90286235_0305 PHO
Cutaway view of a helium atom displaying 1s & 2s orbitals.
EN_90286235_0253 PHO
Sarin nerve gas. Computer artwork of a molecule of the nerve gas Sarin (methylphosphoneflouridic, (1- methyl ester), chemical formula (C4. H10. O2.P.F)). The atoms are shown as spheres and are colour- coded: carbon (blue), oxygen (red), hydrogen (white), phosphorus (yellow), fluorine (green). The bonds between them are shown as cylinders. Sarin (also known as GB) is used in chemical weapons. It is deadly and works in minutes. Skin contact or inhalation leads to disruption of the nervous system leading to convulsions, paralysis and death.
EN_90286236_0070 PHO
Protein molecule.
! EN_90272364_0010 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Periodic table, computer artwork with superimposed generic molecular structure. This table shows the chemical elements arranged in order of atomic number (the number of protons in the nucleus). Elements with similar chemistry occur in the same group (vertical column). Some groups are colour-coded: alkali metals (yellow, left, except H); alkaline-earth metals (purple with white text); transition metals (blue, centre); other metals (purple with yellow text, centre right); halogens (dark orange); inert gases (yellow, far right). The lanthanide and actinide series of elements (dark blue with white text) are shown in the lower two rows.
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90272364_0011 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Periodic table, computer artwork. This table shows the chemical elements arranged in order of atomic number (the number of protons in the nucleus). Elements with similar chemistry occur in the same group (vertical column). Some groups are colour-coded: alkali metals (yellow, left, except H); alkaline-earth metals (purple with white text); transition metals (blue, centre); other metals (purple with yellow text, centre right); halogens (dark orange); inert gases (yellow, far right). The lanthanide and actinide series of elements (dark blue with white text) are shown in the lower two rows.
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90272364_0012 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Periodic table, computer artwork. This table shows the chemical elements arranged in order of atomic number (the number of protons in the nucleus). Elements with similar chemistry occur in the same group (vertical column). Some groups are colour-coded: alkali metals (yellow, left, except H); alkaline-earth metals (purple with white text); transition metals (blue, centre); other metals (purple with yellow text, centre right); halogens (dark orange); inert gases (yellow, far right). The lanthanide and actinide series of elements (dark blue with white text) are shown in the lower two rows.
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90248314_0003 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Bisphenol A, molecular model. This chemical is used in the plastics industry as an antioxidant and as a component of epoxy resins and polycarbonate plastics. There are concerns that increasing levels of bisphenol A in the environment could be harmful. It is already known as a synthetic oestrogen that lowers sperm count in men and is also thought to disrupt foetal development. Atoms are represented as spheres are colour-coded: carbon (black), oxygen (red) and hydrogen (grey).
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90248314_0004 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Bisphenol A, molecular model. This chemical is used in the plastics industry as an antioxidant and as a component of epoxy resins and polycarbonate plastics. There are concerns that increasing levels of bisphenol A in the environment could be harmful. It is already known as a synthetic oestrogen that lowers sperm count in men and is also thought to disrupt foetal development. Atoms are represented as spheres are colour-coded: carbon (blue), oxygen (red) and hydrogen (yellow).
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90248314_0005 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Bisphenol A, molecular model. This chemical is used in the plastics industry as an antioxidant and as a component of epoxy resins and polycarbonate plastics. There are concerns that increasing levels of bisphenol A in the environment could be harmful. It is already known as a synthetic oestrogen that lowers sperm count in men and is also thought to disrupt foetal development. Atoms are represented as spheres are colour-coded: carbon (blue), oxygen (red) and hydrogen (yellow).
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90268567_0001 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Miller-Urey experiment. Artwork of the apparatus used in the Miller-Urey experiment to study the origin of life. This 1950s experiment attempted to duplicate the conditions which would have existed on the primordial Earth. The apparatus contains a 'sea' of sterile water (bottom) and an 'atmosphere' of hydrogen, methane and ammonia (top right). Electrodes give off a spark (right) to imitate either lightning or ultra-violet radiation from the Sun. The result is a tar-like residue containing amino acids, the basic building blocks of life.
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90274300_0003 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Prostacyclin molecule. Computer model showing the structure of the hormone prostacyclin, or prostaglandin I2 (PGI2). Atoms are colour-coded (carbon: dark grey, hydrogen: light grey, oxygen: red). Prostacyclin acts to widen blood vessels (thus lowering blood pressure) and to prevent aggregation of platelets (preventing blood clotting). These effects are the opposite of those of the related hormone thromboxane, and the balance between the two is important in regulating the functioning of the circulatory system. When taken as a drug it is known as epoprostenol.
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90274300_0004 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Prostacyclin molecule. Computer model showing the structure of the hormone prostacyclin, or prostaglandin I2 (PGI2). Atoms are colour-coded (carbon: dark grey, hydrogen: light grey, oxygen: red). Prostacyclin acts to widen blood vessels (thus lowering blood pressure) and to prevent aggregation of platelets (preventing blood clotting). These effects are the opposite of those of the related hormone thromboxane, and the balance between the two is important in regulating the functioning of the circulatory system. When taken as a drug it is known as epoprostenol.
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90274302_0001 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Prostaglandin E1 molecule. Computer model showing the structure of the hormone prostaglandin E1 (PGE1). Atoms are colour-coded (carbon: dark grey, hydrogen: light grey, oxygen: red). PGE1 acts to widen blood vessels (vasodilation), thus lowering blood pressure and improving blood flow. It is therefore used as a drug, known as Alprostadil, to treat erectile dysfunction.
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90274302_0002 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Prostaglandin E1 molecule. Computer model showing the structure of the hormone prostaglandin E1 (PGE1). Atoms are colour-coded (carbon: dark grey, hydrogen: light grey, oxygen: red). PGE1 acts to widen blood vessels (vasodilation), thus lowering blood pressure and improving blood flow. It is therefore used as a drug, known as Alprostadil, to treat erectile dysfunction.
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90274303_0001 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Prostaglandin E2 molecule. Computer model showing the structure of the hormone prostaglandin E2 (PGE2). Atoms are colour-coded (carbon: dark grey, hydrogen: light grey, oxygen: red). Like other prostaglandins PGE2 acts to widen blood vessels (vasodilation), thus lowering blood pressure and improving blood flow. It also relaxes smooth muscles and inhibits the release of noradrenaline. It softens the cervix and causes uterine contraction during labour, and is therefore used as a vaginal suppository (dinoprostone) to prepare the cervix for labour and also to induce labour.
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90274303_0002 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Prostaglandin E2 molecule. Computer model showing the structure of the hormone prostaglandin E2 (PGE2). Atoms are colour-coded (carbon: dark grey, hydrogen: light grey, oxygen: red). Like other prostaglandins PGE2 acts to widen blood vessels (vasodilation), thus lowering blood pressure and improving blood flow. It also relaxes smooth muscles and inhibits the release of noradrenaline. It softens the cervix and causes uterine contraction during labour, and is therefore used as a vaginal suppository (dinoprostone) to prepare the cervix for labour and also to induce labour.
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90274304_0001 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Prostaglandin F2a molecule. Computer model showing the structure of the hormone prostaglandin F2a (PGF2a). Atoms are colour-coded (carbon: dark grey, hydrogen: light grey, oxygen: red). Like other prostaglandins PGF2a acts to widen blood vessels (vasodilation), thus lowering blood pressure and improving blood flow. It is produced by the uterus, where it triggers the breakdown of the corpus luteum (luteolysis) if no embryo has been implanted, and stops the production of progesterone. It is therefore marketed as a drug used to induce abortion (an abortifacient) when it is known as Dinoprost.
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90274304_0002 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Prostaglandin F2a molecule. Computer model showing the structure of the hormone prostaglandin F2a (PGF2a). Atoms are colour-coded (carbon: dark grey, hydrogen: light grey, oxygen: red). Like other prostaglandins PGF2a acts to widen blood vessels (vasodilation), thus lowering blood pressure and improving blood flow. It is produced by the uterus, where it triggers the breakdown of the corpus luteum (luteolysis) if no embryo has been implanted, and stops the production of progesterone. It is therefore marketed as a drug used to induce abortion (an abortifacient) when it is known as Dinoprost.
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90277132_0001 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Salmon calcitonin hormone molecule. Computer model showing the structure of calcitonin from salmon. Atoms are colour-coded spheres (carbon: dark grey, hydrogen: light grey, nitrogen: blue, sulphur: yellow, and oxygen: red). Calcitonin is a linear polypeptide that is produced primarily by parafollicular cells (C-cells) in the thyroid gland. It acts to reduce blood calcium levels by opposing the effects of parathyroid hormone (PTH). Salmon calcitonin is used to treat a number of disorders in humans, including postmenopausal osteoporosis, and hypercalcaemia (high calcium blood levels). It is used as it is rapidly absorbed and eliminated from the body and is therfore safer than the human form.
Wysoka rozdzielczosc dostepna na zamowienie

góra

123
567... z 45