Library

Notes: Recently a new intermolecular potential for C60 was derived from ab initio calculations. Using this new interaction potential we numerically study the phase diagram of fullerite. Several numerical techniques are used in order to ascertain the correctness of the results. We predict that C60 can be found in the liquid state for densities between 0.468 and 0.845 nm−3 and temperatures between 1881 and 2012 K. © 2000 American Institute of Physics.

Notes: The connective tissue organization in the epididymus of Didelpbis azarae was studied in paraffin embedded histologic preparations stained with hematoxylin and eosin; Mallory trichrome and Gomori's Nitrous Orcein and Silver stains. Thc connectcve tissue organization is compared with that of other mammals.

Notes: The thermodynamic properties of coexisting solid and fluid phases are computed for the Lennard-Jones system. We make absolute Helmholtz free energy calculations for fluid and solid reference thermodynamic states and we compute differences in free energy relatively to these states in order to obtain thermodynamic properties in a range of temperatures and densities. For the free energy difference calculations we use a previously developed method [A. L. Ferreira and M. A. Barroso, Phys. Rev. E 61, 1195 (2000)]. Our results are compared with others available in the literature. Furthermore, we present absolute values of the Helmholtz free energy along solid–fluid coexistence lines. © 2002 American Institute of Physics.

Notes: Zusammenfassung Elektronenoptischer Nachweis, dass Skorpiongift (Tityus serrulatus) nach i.p. Verabreichung an der quergestreiften Muskulatur der Küchenschabe eine starke nekrosierende Wirkung ausübt.

Notes: Summary Using a specific technique for biogenic amines, similar cells to those described as small intense fluorescent (SIF) cells were identified in the atrioventricular valves of the opossum heart. It is suggested that these cells, under neural control, may secrete amines.

Notes: Zusammenfassung Die Resultate zeigen, dass der oder die Mechanismen, welche die Mitosis in der Cornea von normalen Tieren synchronisieren, nach partieller Hepatektomie immer noch aktiv sind.

Notes: Zusammenfassung Mittels Fluoreszenztechnik wurde ein mikrochemischer Nachweis der Freisetzung von Katecholamin an adrenergischen Strukturen in den Arterioventrikularklappen des Rattenherzens nach Verabreichung von Skorpiongift (Tityus serrulatus) erbracht.

Notes: Zusammenfassung Bei Ratten, die während 4 Monaten ad libitum 40% igen Zuckerrohrschnaps getrunken hatten, wurden tiefgreifende Degenerationserscheinungen des adrenergischen Nervenplexus der Atrioventrikularklappen festgestellt.

Notes: Abstract Objective: To examine the correlation between the clinical diagnosis and autopsy findings in adult patients who died in an intensive care unit (ICU). To determine the rate of agreement of the basic and terminal causes of death and the types of errors in order to improve quality control of future care. Design: Retrospective study. Setting: Adult ICU in a university hospital. Patients: 30 adult patients who died in the ICU, with the exclusion of medicolegal cases. Methods and main results: Anatomo-clinical meetings were held to analyze the pre- and postmortem correlations in 30 consecutive autopsies at the ICU of the University Hospital, School of Medicine of Botucatu/ UNESP, from January 1994 to January 1997. The rate of correct clinical diagnoses of the basic cause was 66.7 %; in 23.3 % of cases, if the correct diagnosis was made, management would have been different, as would have been the evolution of the patient's course (Class I error); in 10 % of the cases the error would not have led to a change in management (Class II error). The rate of correct clinical diagnoses of terminal cause was 80 %. Conclusions: The rate of recognition of the basic cause was 66.7 %, which is consistent with the literature, but the Class I error rate was higher than that reported in the literature.

Notes: Summary The nuclear volume of the cells of the seminiferous epithelium was studied throughout the stage of the spermatogenesis in the rat, and the moment of the pre-meiotic synthesis of DNA was determined through quantitative histophotometric measurements. During spermatogenesis the cells showed a sudden volume variation from Spermatogonia A until the initial period of stage Pachytene. Next, followed a long period of continuous growth of the nuclear volume, ending at the first meiotic division. The premeiotic synthesis of the DNA was represented by a duplication of the amount of DNA of the nucleus; this happened during the stage Spermatocyte I “resting”, It was not followed by a duplication of the nuclear volume, but by a increase of only approximately 47%. Our data suggest that the sudden modifications in the nuclear volume during the period between the stages Spermatogonia A and Zygotene + Pachytene A, are caused by assynchronic duplication or demediation of two different types of nuclear constituents. The continuous growth of the nuclear volume would depend upon a different mechanism. 1) During spermatogenesis the cells show sudden volume variation from Spermatogenia A until the initial period of stage Pachytene, Pachytene A according to our nomenclature. Taking the nuclear volume during the stages Zygotene and Pachytene A for reference and assuming 2.000 as their arbitrary value, during this period of spermatogenesis the mean nuclear volume evolves as follows: Spermatogonia A: 2.192; Spermatogonia I: 1.532 Spermatogonia B and “Resting A”: 0.957; “Resting B” and Leptotene: 1.407; Zygotene and Pachytene A: 2.000. It is assumed that during this period of the spermatogenesis there are demediations of nuclear volume followed by a return to its initial volume; however, in the latter as well as in the former there are intermediary phases which constitute Schreiber'S “sesquiphases” (1947). 2) Next, follows a long period of continuous growth of the nuclear volume, ending at the first meiotic division. The maximum value observed corresponds to 8.570 in our system of units. 3) The volume of the spermatocyte II is not constant; throughout its existence it increase from a initial value which could not be exactly determined till a volume corresponding to a 2.582 value. This value is well below half of the Spermatocyte I in stage Diplotene. The volume of the spermatid does not change during the initial period of its existence. Its mean value equals 2.146, which is 1/4 of that of the Spermatocyte I in stage Diplotene. After this initial period the Spermatid volume decreases; for technical reasons measurements were not conducted during this period. 4) It was found that the premeiotic synthesis of the DNA is represented by a duplication of the amount of DNA of the nucleus; this happens during the stage Spermatocyte I “resting”. “Resting A” is the stage before the duplication of the DNA. 5) The duplication of the amount of the DNA, in stage Spermatocyte I “resting”, is not followed by a duplication of the nuclear volume, but by an increase of only approximately 47%. 6) Our data suggest that the modifications in the nuclear volume during the period between the stages Spermatogonia A and Zygotene + Pachytene A, are caused by asynchronic duplication or demediation of two different types of nuclear constituents: the first shows a variation proportional to the amount of the nuclear DNA while the variation of the second is not related to the DNA; the latter is called “residual material” in order to avoid any assumptions about its nature. It was possible to calculate the relative volumes related to these two types of constituents. Being 2 N the volume related to the diploid amount of DNA and 2 R the volume related to the “residual material” found in the stage Zygotene + Paohytene A, the following values were calculated, with our system of units: 2N = 0.429: 2 R = 1.108. 7) The observed variations in volume are in agreement with the hypothesis which assumes a variation of the constituents according to the following scheme: Spermatogonia I: 2 N + 2 R; Spermatogonia B and “Resting A”: 2 N + 1R; “Resting B” and Leptotene: 4N + 1R; Zygotene and Pachytene A: 4 N + 2 R. 8) The period of the continuous growth of the nuclear volume from stage Pachytene B till stage Diplotene, depends upon a different mechanism, as the “residual material” does not vary in simple definite proportions. 9) During the first meiotic division the “residual material” seems to pass into the cytoplasm. It returns, only partially, to the nucleus during the life-span of Spermatocyte II. After the second meiotic division, the “residual material” returns completely to the nucleus of the Spermatids; therefore, the whole four daughter spermatids, originating from one Spermatocyte I, contain exactly the same amount of “residual material” found in Spermatocyte I, immediately before its first meiotic division.