Pen Nib Research Articles

A pen smear technique for assays of rosette-forming lymphocytes

A simple technique is described for the preparation of permanent stained smears of human E-rosetted lymphocytes. Smears of the cells suspended in foetal calf serum were drawn as thin strips on slides with a pen nib. Such smears, after Romanowsky staining, and incorporating latex-particle phagocytosis as a marker for non-lymphoid cells, show excellent rosette preservation and permit easy distinction and counting of rosetting lymphocytes, non-rosetting lymphocytes, monocytes and granulocytes. The percentages of rosette-forming lymphocytes estimated on such smears correspond closely to those obtained from counts made on viable cell suspensions.

Experimental Study of the Effects of Jet Noise on an Aircraft Structure

Reports of noise effects on the rear fuselage structure of large British aircraft indicated that one might expect noise damage in this region on the Vickers Supermarine Type 544 aircraft. It will be seen from Fig. 1 that the jet efflux from each engine passes close to the fuselage side and under the tailplane. The fuselage structure proper is, however, protected from the heat and noise effects at the jet efflux by a fairing which is insulated at all attachments. This fairing, by virtue of its shape, is called the “ pen nib. ”