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In this article, the authors focused on real measurements of mechanical turbulence generated by ventilators in the simulation box for Optical Wireless Communications. The mechanical turbulences disturb the optical beam that propagates along the central axis of the simulation box. The aim of authors is to show the effect of mechanical turbulence on optical beams at different heights in the simulation box. In the Ansys Fluent, we created numerical models which were then compared with real measurements. Authors compared the real and numerical models according to statistical methods.

Article is dealing with defining of mathematical turbulent air flow numerical model in the laboratory box with help of ANSYS Fluent software application. The paper describes real measurement of parameters of mechanical turbulences created by high-speed ventilator mounted on the simulation box. The real measurement took place in two planes perpendicular to each other, input and output slot. Subsequently the simulation of mechanical air flow was performed by the help of k-ε and k-ω turbulent models. The results of individual simulations were evaluated by statistical model in the same points, planes respectively, in which the real measurement was made. Other simulation was dealing with effect of heaters inside of closed laboratory box with regards to optical beam degradation. During real measurement was performed temperature point measurement by probe placed inside of the box. The probe was recording air temperature every one second during seven minutes long measurement. The results comparison of simulated and measured data was made in the end. The maximal temperature reached approximately 50 °C in both cases. Also the air flow character in dependence on the number of hot-air extraction ventilators was monitored.

This paper presents the construction of an innovative high-temperature sensor based on the optical principle. The sensor is designed especially for the measurement of exhaust gases with a temperature range of up to +850 °C. The methodology is based on two principles-luminescence and dark body radiation. The core of this study is the description of sensing element construction together with electronics and the system of photodiode dark current compensation. An advantage of this optical-based system is its immunity to strong magnetic fields. This study also discusses results achieved and further steps. The solution is covered by a European Patent.

Background: The survival of patients with neuroendocrine tumors has substantially improved with modern treatment options. Although the associated carcinoid syndrome can be diagnosed early and controlled effectively, cardiologists still encounter patients with cardiac manifestations, particularly among individuals with persistently high levels of vasoactive mediators. Treatment options have been limited to surgical valve replacement in fully manifested disease. Since surgery is not always feasible, transcatheter valve implantation is becoming an interesting alternative., Case: A case of a 50-year-old woman with carcinoid syndrome and right-sided valvular heart disease is presented. Moderate pulmonary valve stenosis and severe tricuspid valve regurgitation were diagnosed during the evaluation and treatment of neuroendocrine tumor. The possibility of rare valve involvement and the need for interdisciplinary cooperation in the diagnosis, monitoring and treatment of patients with neuroendocrine tumors producing vasoactive substances must be emphasized., Conclusion: The patient had a typically presenting carcinoid syndrome with a rare cardiac manifestation. Although monitoring and treatment were carried out in accordance with recommendations and appropriate to the clinical condition, rapid progression of the metastatic disease ultimately precluded invasive cardiac intervention.

Introduction: Elderly cryptogenic ischemic stroke (IS) patients with embolic stroke of undetermined source (ESUS) have a high risk of recurrent IS (RIS) compared to other stroke subtypes. In young ESUS patients, different sources of embolism may be a cause and the risk of RIS remains not enough established. The aim was to assess and compare risk of RIS between ESUS and non ESUS patients <50 years., Methods: The study set consisted of young acute IS patients <50 years enrolled in the prospective HISTORY (Heart and Ischemic STrOke Relationship studY) study registered on ClinicalTrials.gov (NCT01541163). In all analyzed patients, the brain ischemia was confirmed on CT or MRI. All patients underwent identical diagnostic protocol including TEE and long-term ECG-Holter. Cause of IS was assessed according to the ASCOD classification., Results: Of 320 enrolled patients <50 years, 219 (68.4%) were identified as cryptogenic (119 males, mean age 41.4 ± 7.2 years) and 122 (38.1%) patients fulfilled the ESUS criteria. During the follow-up with a median of 34 months, three (2.5%) ESUS and 5 (5.2%) non-ESUS patients suffered from RIS (p = .471). One-year risk of RIS was 0.008 (95% CI: 0-0.025) for ESUS and 0.036 (95% CI: 0-0.076) for non-ESUS patients (p = .262)., Conclusion: The risk of RIS was very low in ESUS patients and did not differ from those with non-ESUS. Our finding may indicate that antiplatelet therapy can be effective in the secondary prevention in young ESUS patients if high-risk sources of embolization are excluded extensively., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The authors summarize the existing findings on the treatment of gunshot wounds of the spine and spinal cord which in their country have become an important cause of mortality and morbidity. Their own experience prove the findings of the authors, i.e. that the seriousness of the initial neurological condition can be hardly influenced and an urgent surgical decompression does not improve statistical prospects of the correction in any type of neurological deficit either, with the exception of cauda ae-quina syndrome. They point out that occurrence of complications such as infections, liquor fistula or instability is from the statistical viewpoint significantly higher in patients operated on. They discuss the role of a routine antibiotic prophylaxis and corticotherapy.The stability of spine is usually not impaired by gunshot wounds and as a rule it does not reqiure stabilization by implants.Therefore they recommend to consider the occurrence of instability on a caseby-case basis. Key words: penetrating spinal injury, spinal injury.

Spinal surgery dealing with reparation of injury consequences by stabilisation implantates is a relatively new surgical branch. The experience and results at individual departments in Slovakia in this field differ significantly as to their qualitative degree. The Trauma Surgery Department IVZ in Bratislava and the National Rehabilitation Center in Kovácová cooperate since 1989 in a mutual spinal programme. 177 out of 189 patients survived after undergoing a surgical treatment due to the injury of the lower cervical spine performed from 1988 to 1994. 68 patients (Frankel A, B, C) were included into the spinal programme. The authors present the therapeutical results evaluated according to morphologic, neurologic, functional and subjective criteria. The most frequently used stabilizing method is the so-called method of Caspar and the technique of Morscher, the latter being less frequently applied. Both methods are fully secure, causing minimal blood loss, perfectly stable as to the angle and axis. Both techniques enable a sufficient approach to the decompression of the spinal cord. Since they do not demand any additional external rigid fixation, they are excellently tolerated by patients and only minimally restrict movement. (Tab. 2, Fig. 4, Ref. 8.)

Cervical spondylotic myelopathy, the most frequent type of spinal cord's function impairment in patients over 55 years of age, is caused by mechanical and dynamical changes in the degenerating lower cervical segment of the spine leading to the reduction of the perimedullar space, disturbing thus the blood supply or spinal cord per se. The clinical picture of neurologic changes and their development is very variable. The suspicion of CSM is supported by the finding of the stenosis of the spinal canal to 11 mm, or the decrease in Pavlov's index below 0.8. The diagnosis is based dominantly on CT myelographic examination and MRI. Operative solution has a favourable prognosis providing that the irreversible changes in the spinal cord are absent. (Tab. 1, Fig. 7, Ref. 12.)

The authors discuss the still persisting view among the medical public that surgical stabilization of the injured cervical spine by a ventral approach is associated with a greater surgical risk and with complications. In a group of 101 patients after ventral stabilization who were followed up for more than 12 months following operation the authors recorded peropera-tive haemorrhage in 1.98% of patients, diagnosed peroperative injury of the parapharynx in 1.98%, with undetected injury of the oesophagus and subsequent deep infection in 0.99%. As to technical complications, loosening of screws was recorded in 0.99%. Other complications such as infections, necrosis or collapse of a stitch, or wound infection, were not encountered. In none of the patients neurological deterioration (not even temporary) was found. The authors conclude that ventral stabilization of the injured cervical spine is a safe surgical technique, the incidence of complications being comparable with other operations. Its benefit is much greater than the surgical risk. Key words: surgical complications, cervical spine, ventral stabilization.

Ipsilateral segmental fractures of the diaphysis and the upper end of the femur are relatively rare. They are encountered more frequently in patients with multiple injuries. The basic prerequisite of treatment is an early and accurate diagnosis which may prove difficult in particular in patients with multiple injuries. Conservative treatment is associated with a high incidence of complications, therefore the authors recommend urgent or early surgical stabilization of both fractures. As a rule the method of open reposition and stabilization by plates according to principles of the AO school with the known advantages and shortcomings of this method is used. The authors found intramedullary osteosynthesis by a combination of interlocking nailing and the use of screws useful in intracapsular fractures or else Ender's method in case of the localization of the proximal fracture in the trochanteric area. In both types of fractures new types of nails are useful (long Gamma nail, reconstruction nail of the second or third generation) which before now were not available. Key words: ipsilateral femoral fractures, surgical treatment.

The authors provide a review of current opinions on the treatment of fractures in the region of C1 and C2. It is necessary to take the possibility of this localization of fractures into consideration in polytraumatized patients, in those unconscious, and in cases of algesia in the cervical region. A significant post in diagnostics belongs to CT examination which reveals the extent and type of fracture and the degree of dislocation. The authors refer to the classification of Aebi and Nazarian which should be accepted in spondylo-surgical practice. The authors recommend conservative therapy of atlas fractures, preferably by the use of Halo-apparatuses. The direct osteosynthesis by means of two compressible screws according to Böhler/Magerl represents the method of choice in treating dens fractures. The surgical modification utilizing a small T splint was proved competent in fractures interfering the vertebral corpus (type III). Fractures of isthmus with no dislocation are recommended to be treated conservatively by the use of Halo-fixation, in cases with dislocation (types E II, E III) they consider the method of intercorporal desis C 2/3 according to Decaulx and modified by Caspar, to be optimal. (Fig. 8, Ref. 20.).

The authors present their own experience with the surgical treatment of fractures of the isthmus axis. They discuss contemporary classifications and give indications for surgical treatment. They consider direct compressive osteosynthesis, as described by Judet, performed by a posterior approach as excessively risky for the patient because of possible damage of the vertebral artery and structures of the spinal cord. They substituted this operation by indirect stabilization on Decaulx' principles. The advantage of this method, using an anterior approach, is also immediate treatment of the damaged disc. The authors describe their own experience with both techniques and similarly as in surgical stabilization of the dens they consider it the method of choice. In all cases of surgically treated isthmic, dislocated fractures a firm osseous connection was established with practically no functional restrictions of the cervical segment.

The authors present their experience with surgical treatment of fractures of the dens axis. In a group of surgical stabilizations after 295 injuries of the spine fractures of the dens axis account for 6.1 %, in the cervical segment 18.4 %. The mean age of the patients was 54.8 years, all were free from neurological deficit. The authors discuss classifications of fractures of the dens and indications for surgical treatment. They present all methods known at present which are used for surgical stabilization as well as their own experience with their use. With regard to favourable functional results in their own material, without any complications during the peroperative period, they consider surgical stabilization a safe method of choice and the still most widespread method with halo apparatures rather inadequate. Key words: dens axis, surgical treatment of fractures of the dens.

Indications of appropriate treatment of tibial shaft fractures are one of the priority problems present-day traumatology has to address. In choosing the optimal mode of treatment of tibial shaft fractures not only the configuration of the fracture but also injury of soft tissues has been assigned increasing importance. At the Department of Traumatology of the Postgraduate Institute of Medicine in Bratislava, 962 tibial shaft fractures were treated over the period of 12 years from 1977-1988. Conservative treatment was applied in 600 fractures and 362 fractures were treated surgically. The therapeutic results obtained by using the newly introduced methods of treating tibial shaft fractures, i.e. functional plating and osteosynthesis by flexible Ender nailing, were analyzed in a retrospective and prospective study. The results of these approaches were compared with those achieved by classical methods of the AO school, rigid intramedullary nailing and external fixation. The favorable outcome of union and the good functional effect obtained in the studied and compared series of patients indicate that conservative functional treatment is the method of choice in tibial shaft fractures. Of the surgical therapeutic methods, flexible as well as stable intramedullary osteosynthesis by Ender nailing proved to be both the most sparing and the most physiological approach. The paper proposes an indication scheme of tibial shaft fracture treatment designed for clinical use considering the categorization of fractures according to up-to-date classification. For each type of tibial shaft fracture and soft tissue injury the optimal mode of treatment is suggested. Besides the main indication, possibilities of alternative treatment are also being pointed out.

The presented review analyzes the problem of the effect of electric current and electromagnetic fields on bone healing. The findings of the cited papers indicate that electronegativity, osteoblastic activity and bone formation fall within one group, while electropositivity, osteoclasia and resorption constitute another group. Stimulation is performed surgically by implanted electrodes or by current induction in the bone. Evidence on the effect of direct electric stimulation and pulsed magnetic filds in speeding up the process of bone healing fails to be convincing. However, the beneficial influence of electromagnetotherapy on the healing of soft tissues has been confirmed and is to be ascribed t its antiedematous, analgesic and antiinflammatory effect.