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SummaryUsing an established line of L-cells and 230 kv x-rays, we studied survival properties and recovery after irradiation. Results of experiments seem to be in agreement with those published for Chinese hamster and HeLa cells. L-cells are capable of recovery after x-irradiation. The processes responsible for recovery start promptly after irradiation. The progeny of surviving cells, i.e. sublethally-damaged cells, display complete recovery some time after the first exposure of 375 r (10 per cent surviving cells). The results are compared to those described by Elkind and Lockart for Chinese hamster and HeLa cells.

Resistivity measurements have been made on a number of samples of ultrarapidly quenched aluminium containing up to 4.2 at% iron during their annealing. A phase transition occurring at about 300 °C has been interpreted as due to the liberation of the metastable phase Al6Fe within the alloy. A value of (1.2 ± 0.4) eV has been derived for the activation energy of this transition. No variation of this value with iron concentration has been observed in the interval 0.67 to 1.32 at%.

MUCH more is known about the molecular constitution of the storage mechanism for catecholamines than about how acetylcholine (ACh) is stored, although morphine and related drugs are known to inhibit its release. Because adenosine triphosphate (ATP) seems to be involved in the storage of catecholamines in the chromaffin granules of the adrenal medulla we looked for a special affinity between morphine and various phosphorylated nucleosides which might be concerned in the storage of ACh. Acetylcholine itself could not be tested by these techniques because it lacks native fluorescence.

The age-dependent, ultraviolet light (UVL) (254 nm)-induced division delay of surviving and nonsurviving Chinese hamster cells was studied. The response was examined after UVL exposures adjusted to yield approximately the same survival levels at different stages of the cell cycle, 60% or 30% survival. Cells irradiated in the middle of S suffered the longest division delay, and cells exposed in mitosis or in G 1 had about the same smaller delay in division. Cells irradiated in G 2 , however, were not delayed at either survival level. It was further established, after exposures that yielded about 30% survivors at various stages of the cycle, that surviving cells had shorter delays than nonsurvivors. This difference was not observed for cells in G 2 at the time of exposure; i.e., neither surviving nor nonsurviving G 2 cells were delayed in division. The examination of mitotic index vs. time revealed that most cells reach mitosis, but all of the increase in the number of cells in the population can be accounted for by the increase of the viable cell fraction. These observations suggest strongly that nonsurviving cells, although present during most of the experiment, are stopped at mitosis and do not divide. Cells in mitosis at the time of irradiation complete their division, and in the same length of time as unirradiated controls. Division and mitotic delays after UVL are relatively much larger than after X-ray doses that reduce survival to about the same level.

The angular dependence of the photographic response of a film badge, consisting of Ilford PMI film in combination with 1 mm thick filters of Al, Cd and Sn, exposed to 60Co 226Ra or 137Cs gamma-rays, were studied in detail. Photographic densities as functions of angles of incidence are examined for bare films and paper-wrapped films with filters in front of, behind, and on both sides of the film. The results are presented and an attempt made to explain them. The photographic densities of the parts of the paper-wrapped films covered by filters on both sides were found to be practically angular independent, irrespective of the radiations used.

Erze aus zwei Versuchsbauen auf Cu, Ni, Co und Edelmetalle wurden mikroskopisch und mit der Mikrosonde untersucht. Die Schurefe liegen an einer riesigen Bewegungszone im Serpentin in Sud-Cypern. Die hochst ungewohnliche Paragenese zeigt starke, auf geringste Erstreckung wechselnde Umbildungen. Die Vorkommen selbst sind durch reichlichen bzw. sehr zurucktretenden Anteil an Pyrrhotin verschieden. Trager von Cu ist neben Chalkopyrit Cubanit und sehr reichlich valleriit; von Ni-Pentlandit, Heazlewoodit, Mackinawit, Oregonit; von Co zwei wahrscheinlich neue As-arme Co-Arsenide. Begleiter sind u.a. Pyrrhotin, Chromit, Magnetit, Graphit und Molybdanit, an Gangarten vorwiegend Serpentinmineralien, wenig Carbonate. — Die Lagerstatten geben Gelegenheit, die seltenen Mineralien Mackinawit, Valleriit und Oregonit nebeneinander im Verband und in ihren Beziehungen zu Pentlandit und Chalkopyrit zu untersuchen. Die Mineralisation scheint wahrend der tektonischen Veranderung des Serpentins erfolgt zu sein.

The hybridization in several cyclic polyacetylene compounds has been calculated by the maximum overlap method, assuming planar and non-planar geometries of the molecules. In the planar configuration the hybrids describing the molecular skeleton deviate from the corresponding bond directions. We have a few “bent” bonds, but in contrast to the situation in small rings, here the deviation angles are negative, i.e., the hybrids point toward the inside of the ring. Non-planar structures in which acetylene groups are kept in a plane and CCH2 or CH2 groups are displaced out of the plane show less deviation from the bond directions of bent bonds. Furthermore, the deviation angles decrease with an increase in the out-of-plane displacement of methylene groups. Finally, when the angle of bending of the molecules approaches 50°, the deviation vanishes, predicting a puckered conformation for the molecules. Correlation between CC stretching vibration frequencies and the corresponding CC bond overlap is discussed.

Maubeuge Pierre-louis,Antun Paul. Observations sur le Lotharingien et le Carixien du Grand-Duché de Luxembourg. In: Bulletin de la Classe des sciences, tome 53, 1967. pp. 249-255.

From November 14 1967 to February 28 1969 the author inserted Lippes loops sizes A B C or D into 1000 women. Excluding those women who expelled the loop and those from whom it was removed 88.4% of the women continue to wear the device. 36.4% of the women expelled the loop within the first month but there were virtually no expulsions after 3 months. The device was removed from 15 women because of persistent severe intransigent metrorrhagia. 25 pregnancies occurred. 24 were intrauterine and 1 was tubal with the loop remaining in the uterine cavity. The patient with the tubal pregnancy went to the hospital twice with a diagnosis of acute appendicitis. She had been using the IUD for 8 months. On further investigation and testing it was discovered that the right fallopian tube was ruptured 3 cm from isthmus. The tear was 2 by 3 mm. The right ovary was enlarged nearly to the size of an apple. There were 1500 cc of liquid and clotted blood in the abdomen. The pathologist reported tubal pregnancy endometriosis and red corpus luteum. During the operation the patient was transfused with 1250 cc of blood. She had an uneventful postoperative course and was discharged on the twelfth day. It was observed by the author that when patients are informed of the pregnancy possibilities despite the use of the IUD their desire to employ the device decreases sharply.

IN discussions of the nature of the receptor site for central transmitters in neuronal membrane it is usually assumed that it must be composed of protein or perhaps glycoprotein. Because RNA has been reported to be present in membrane1–5 and because it may well have functions in the cell besides its direct involvement in protein synthesis, however, it is possible that ribonucleoprotein may have a part to play in membrane function (for example, opening ionic channels, and making up part of the receptor site in neurones). A detailed development of this hypothesis has been presented elsewhere6,7. This article is concerned with experiments attempting to determine the mechanism of binding of tryptamine and related compounds to nucleic acids.