Volume 67 (2019): Edizione 2 (June 2019)

The previous article described a new approach methodology¹ for work on the development of technology for the use of the SCR CRABE SCUBA² type diving apparatus. However, after its publication numerous questions emerged regarding the genesis of the research undertaken, also from foreign partners using the same rebreather. The work on changing the technology of use was preceded by analyses, which were available only to people involved in the decision-making process. Demonstrating all the details of the decision-making process may be tedious, but failing to present them at all might raise justified doubts about the advisability of conducting a long-term research cycle.

This article only presents preliminary analyses. The necessity to perform them resulted from the specific requirements for military technologies³ which, as broadly as possible, should be knowledge-based. The knowledge-based approach by its very nature allows continuous improvement of the adequacy of the predictions made, the estimation of the level of risk when diagnosing deviations from the repeatability or precision of the model, and the possibility of adapting the technology to the changing requirements of the user resulting from tactical considerations of its use.

Continuing the discussion on the description of adsorbate-adsorbate association on homogeneous surfaces of solids, an attempt was made to formulate an analytical form of adsorption equation for a multilayer adsorption phase. The validity of Berezin’s and Kiselev’s assumptions concerning the independence of adsorption in further layers from the model of the phenomenon in the first of them was discussed. The fundamental validity of this assumption has been demonstrated, simultaneously ridding it of its arbitrary character. The main aim of the study was to demonstrate the possibility of formulating a description assuming molecule association in the entire adsorption phase (and not only in the first layer). Theoretical considerations are confined to the case of dimerisation in the concentration range thus warranting the approximation characteristic of the Berezin and Kiselev model. The obtained final adsorption equation exhibits physically acceptable boundary properties; with adequate assumptions it amounts to the Brunauer, Emmett and Teller equation, the equation formulated earlier by one of the authors of this paper or the Langmuir equation.

In the article the author describes the Polish specificity of deep dives used in underwater deep-sea works. The article briefly discusses the methods of deep diving used in the world to proceed to underwater works in the Polish offshore zone of 50-90m depth (according to the Act; deep water works are works below a depth of 50m). When discussing these methods, the author describes the technical-organisational and formal conditions and the type of conducted works. It then presents the methodology for evaluating the effectiveness of the main element of deep-sea works, i.e. diving. It provides information on deepsea underwater works on the Baltic Sea carried out by the Department of Underwater Works Technology of the Naval Academy in cooperation with the Polish Navy until 2001 and civil companies to date. On the basis of his own data from underwater deep-sea works, the author presents the methodology of evaluation of their effectiveness from the point of view of deep dives. In his conclusions, he puts forward recommendations for improving the efficiency of such works.

Patent foramen ovale (PFO) is a condition present in 25% of the adult population. It is a remnant of fetal foramen ovale which allows blood to pass from the right to the left atrium, bypassing the fetal lungs. In majority adults it does not have any clinical significance, but in some people it may allow shunting of venous blood into the left atrium (right – left – shunt or RLS), circumventing the lung filter, especially during sneezing, cough, lifting heavy equipment. Is such case, PFO may be a route for venous emboli or gas bubbles from veins to the arterial system. It is known as a paradoxical embolism and may be cause of ischaemic stroke or neurologic decompression sickness (DCI), inner-ear DCI and cutis marmorata. Transesophageal echocardiography is considered as a reference standard in detection of intracardial shunts. Its sensitivity and specificity ranges between 94%-100%. However, TEE is an invasive examination with potentially serious side effects. An alternative examination in RLS detection is contrast enhanced Transcranial Doppler (the bubble study or c-TCD). In comparison to TEE, Transcranial Doppler is not invasive, relatively not expensive and save technique. With its high sensitivity and specificity in detection of PFO, 97% and 93% respectively, it may improve detection of RLS and allow to conduct screening examination for PFO in divers.

Hyperbaric oxygen (HBO) treatment is generally a relatively safe therapy for various conditions. However, there are some adverse side effects. For example HBO tratment has been reported to increase the production of free oxygen radicals(FRs). Furthermore, to our knowledge, no previous clinical research has been carried out to study the involvement of platelet-activating factor(PAF)as the lipid oxidative stressor in patients undergoing HBO treatment. A total of 45 patients included in this study were first given clinical assessment and laboratory measurements before starting HBO treatment and were named group baseline. After the HBO treatment, the same clinical and laboratory measurements from the same patients were repeated and this was named group sesion >20.As expected, long-term HBO treatment had no effect on oxLDL (oxidized low-density lipoprotein), a lipid oxidative stress(OS) marker. However, the mean PAF values in the second group showed a statistically significant increase compared to their pretreatment values, (P <0. 002).As this is a preliminary study, there is a need for more detailed investigations that demonstrate the association of HBO treatment with the lipid inflammatory response. Therefore, there is need for further clinical study for OS markers such as oxLDL in HBO treatment. Clinical prospective studies are required to confirm our laboratory findings.