Synthesis has a central role in the development of Science especially in Chemistry.
The strategies adopted in synthesis of molecules and materials have undergone
considerable changes in recent times and it was felt that it may be necessary to
assess and assimilate information on this topic in a single place. Though, no
originality is claimed to the contents on this topic, the very fact that the available
information on this topic is available in one place itself is considered to be a major
Pantogin được bào chế từ sâm nhung, là “loại thuốc bổ đầu tay”. Thành phần có hoạt tính chủ yếu của nhân sâm là hỗn hợp 30 triterpenoid saponin, được gọi là các ginsenoside, chúng thể hiện những tác dụng sinh học rất đa dạng trong đó có tác dụng chống oxy hoá.
Measurement of Serum Bilirubin
The terms direct- and indirect-reacting bilirubin are based on the original van den Bergh reaction. This assay, or a variation of it, is still used in most clinical chemistry laboratories to determine the serum bilirubin level. In this assay, bilirubin is exposed to diazotized sulfanilic acid, splitting into two relatively stable dipyrrylmethene azopigments that absorb maximally at 540 nm, allowing for photometric analysis. The direct fraction is that which reacts with diazotized sulfanilic acid in the absence of an accelerator substance such as alcohol.
A slight loss of refrigerant is recognized by ‘bubbles’ in the liquid-indicating
sight glass installed in the liquid line of a system, a loss of performance,
partial frosting of the evaporator and lower than normal operating pressures.
Refrigerant may be added in vapour form to the low side of the system if the
refrigerant is azeotropic such as R502. This means that it reacts as a single
The zeotropic refrigerant blends do not react in a similar manner and they
should be added to a system in liquid form. ...