Having studied the available printed, visual, and verbal sources from Russia, South Africa, the USA, and Germany, we have identified and reviewed in the article the facts of face-to-face and correspondence communication between V.P. Demikhov, the "father" of experimental heart transplantation (Moscow, USSR), and C.N. Barnard, a pioneer of clinical heart transplantation (Cape Town, South Africa). We have shown that C.N. Barnard mastered the heart surgery techniques, including those under conditions of artificial circulation, in the USA in 1956-1958, and later improved them in his homeland both in clinic (heart surgery for cardiac defects), and in the experiment (heart transplantation). The main events preceding the first world human heart transplant performed by C.N. Barnard on December 3, 1967, were his trip to the United States in August 1967 to study immunosuppression techniques, and the kidney transplantation he had performed in Cape Town in September, 1967. Prior to that time, C.N. Barnard had visited the USSR only once, in May 1960, as a delegate to the XXVII All-Union Congress of Surgeons. In the Soviet Union, he visited a number of clinics dealing with heart surgery and tissue and organ transplantation, including the N.V. Sklifosovsky Institute for Emergency Medicine, where he met V.P. Demikhov, but C.N. Barnard could neither talk to him personally, nor watch his operations. In December 1967, V.P. Demikhov spoke with C.N. Barnard on the phone, but the conversation was highly professional. This paper has shown different approaches of V.P. Demikhov and C.N. Barnard to the transplantation problem: the Soviet surgeon paid more attention to the transplantation technique, meanwhile, the South African surgeon considered the solution of immunological problems to be the basis of success. Nevertheless, C.N. Barnard knew about V.P. Demikhov's scientific achievements and used some of them in his surgical practice. The authors have substantiated the interaction between V.P. Demikhov and C.N. Barnard as between an ideological mentor and a student (in a broad sense) rather than as a teacher and a student (in a narrow sense). Therefore, in a broad, philosophical sense, the Soviet surgeon can be considered one of the inspirers of the world's first heart transplantation, which, in turn, proved that his ascetic work was not in vain.

Este estudo investiga a possibilidade do uso da perfilagem geofísica de gama natural e resistividade na discriminação de estratos carbonosos, em relação a outras litologias presentes em quatro depósitos de carvão localizados no Rio Grande do Sul (áreas B3, Calombo, Cerro e Seival). Uma vez observada a possibilidade de identificação dos estratos carbonosos com estes dois perfis geofísicos apenas, fez-se uma verificação da acuracidade na determinação das espessuras das camadas de carvão. Neste contexto, as espessuras das camadas de carvão foram comparadas com as espessuras observadas em testemunhos de sondagem, sendo que o reconhecimento das assinaturas das camadas pode ser feito com boa acuracidade para todos os depósitos, exceto no depósito do Cerro, onde o sinal do carvão confunde-se com o sinal de arenitos, inviabilizando muitas vezes a discriminação. Ressalte-se a importância deste tipo de avaliação, especialmente quanto às espessuras de camadas de carvão no planejamento de mina de curto prazo, onde não é exequível a sondagem com recuperação de testemunhos em bancadas de lavra simultaneamente ao processo extração de carvão, em função da demora da atividade de sondagem e custos elevados.