The Chemistry Of Permanent Hair Dyes
Ludwig Wilhelm Carl Rehn (1849–1930)
In mid 1890s that a German surgeon reported the first cases of bladder cancer in dye workers
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Blood Pressure Graph
5 th April
International Day Of Conscience
Conscience = Moral Compass
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The neuron doctrine is the concept that the nervous system is made up of discrete individual cells, a discovery due to decisive neuro-anatomical work of
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Photomicrographs from Cajal’s preparations (housed in the Museo Cajal at the Cajal Institute, Madrid, Spain) of the cerebral cortex of a newborn infant, showing neurons impregnated by the Golgi stain. These two photos have also been published in DeFelipe and Jones “Cajal on the Cerebral Cortex.” Oxford University Press, New York, 1988.
Cajal’s drawing of the cerebellar cortex (from a preparation of the cat cerebellum stained with methylene blue) showing the axons of Purkinje cells which exit from the cortex directed downwards.
The Chemistry Of Body Odour
Thiol
Human sweat contains (3-methyl-3-sulfanylhexan-1-ol) detectable at 2 parts per billion and having a fruity, onion -like odor.
A specific thiol (3-methyl-3-sulfanylhexan-1-ol) and a specific acid (3-hydroxy-3-mehylhexanoic acid) have been identified as the major components of human sweat malodor, both arising from the action of bacteria on protein metabolites secreted by sweat glands.
Interestingly, women liberate more of the onion-like acid than men, likely due to gender differences in bacterial composition.
Snapshot
Our noses are extremely good at detecting these thioalcohols at extremely low thresholds, which is why they are really important for body odour. They have a very characteristic cheesy, oniony smell that you would recognise
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