Septa alternatives

The submitters report bp 86-87°C (0.3 urn). (E)-1-Hexenyl-1,3,2-benzodioxaborole is quite air stable, but it can slowly hydrolyze to boronlc acid and turn brown on repeated use in air. The submitters recommend storing it at refrigerator temperature In a bottle purged with nitrogen and capped with a rubber septum. Alternatively, the crude 1-hexenyl-1,3,2-benzodioxaborole can be used for the next coupling reaction without purification. In this case, the unreacted 1-hexyne should be removed under reduced pressure (0.1 mn for 30 min), because it also reacts with (Z)-6-bromostryrene to afford (lZ)-l-phenyl-l-octen-3-yne. In this manner the expected diene was obtained in a yield of 86%. 

Statistical control of an analysis or instmment is best demonstrated by SQC of a standard sample analysis. The preferred approach to demonstrate statistical control is to use a reference sample of the subject material that has been carefully analyzed or, alternatively, to use a purchased reference standard. Either material must be stored so that it remains unchanged, eg, sealed in ampuls or septum capped bottles. Periodically a sample can then be reanalyzed by the technique used for routine analysis. These results are plotted in a control chart. Any change in the stabihty of the test in question results in a lack of... 

Parent M, Laurey P, Wilkniss S, Gold P. 1997. Intraseptal infusions of muscimol impair spontaneous alternation performance Infusions of glucose into the hippocampus, but not the medial septum, reverse the deficit. Neurobiology of Learning and Memory 68(1) 75-85. 

Remove 15 pi clear supernatant, preferably through the septum (or alternatively using an HPLC automatic injection device), and inject into an HPLC system. 

An alternative to the syringe technique for the transfer of liquids uses the double-ended needle and is suitable when it is not necessary to know precisely the volume of liquid being transferred, or when the volume is being measured in some other way, e.g. by transfer from a septum-capped measuring cylinder. This... 

An alternative to the use of the one-necked flask described above is to use the apparatus shown in Fig. 2.77. In this case a two-necked flask is used, with the septum which is used for the addition or removal of liquids fitted to one arm of the flask and a three-way stopcock to the other. With this arrangement it is not possible to isolate the septum from the reaction flask. Should this be required the septum is fitted to a stopcock in the second arm of the flask. Flasks with an integral stopcock are available commercially. 

C Schuster, B Dobrinski, R Hakenbeck. Unusual septum formation in Streptococcus pneumoniae mutants with an alternation in the DD-carboxypeptidase penicillinbinding protein 3. J Bacteriol 172 6499-6505, 1990. 

Other lantibiotics that do not have the ability to form pores and indeed do not cause cell leakage have nevertheless still an impressive antibacterial effect in vivo. With respect to this, an alternative mechanism of antibacterial activity was recently described by which members of the lantibiotic family kill Gram-positive bacteria by binding lipid II and removing it from the cell division site (or septum) and thus block cell wall synthesis [35]. 

Reagents can be added through the 3-way tap, provided a syringe with a long needle is used, or as an alternative a flask with a side arm fitted with a septum can be used. Whilst the temperature of a reaction is changing the bubbler of the system should be checked to make sure there is a constant inert gas pressure. 

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