Construction of a High-Temperature Sensor for Industry Based on Optical Fibers and Ruby Crystal.

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.

Inquiry into the Temperature Changes of Rock Massif Used in Energy Production in Relation to Season.

This research was undertaken to perform and evaluate the temperature measurement in the ground utilized as an energy source with the goal to determine whether significant temperature variations occur in the subsurface during the heating season. The research infrastructure situated on our University campus was used to assess any variations. The observations were made at the so called "Small Research Polygon" that consists of 8 monitoring boreholes (Borehole Heat Exchangers) situated around a borehole used as an energy source. During the heating season, a series of monthly measurements are made in the monitoring boreholes using a distributed temperature system (DTS). Raman back-scattered light is analysed using Optical Frequency Time Domain Reflectometry (OTDR). Our results indicate that no noticeable changes in temperature occur during the heating season. We have observed an influence of long-term variations of the atmospheric conditions up to the depth of a conventional BHE (≈100 m). The resulting uncertainty in related design input parameters (ground thermal conductivity) was evaluated by using a heat production simulation. Production data during one heating season at our research facilities were evaluated against the design of the system. It is possible to construct smaller geothermal installations with appropriate BHE design that will have a minimal impact on the temperature of the surrounding rock mass and the system performance.

Determination of the prevalence and predictors of ventricular thrombus with assessment of the risk of systemic embolization to the CNS in patients after acute myocardial infarction using magnetic resonance imaging, echocardiography and cardiac markers - a prospective, unicentric, observational study.

BACKGROUND: Left ventricular thrombus (LVT) formation is one of the well-known and serious complications of acute myocardial infarction (AMI) due to the risk of systemic arterial embolization (SE). To diagnose LVT, echocardiography (TTE) is used. Late gadolinium-enhanced cardiovascular magnetic resonance (DE-CMR) is the gold standard for diagnosing LVT. OBJECTIVES: The aim of this observational study was to determine the role of transthoracic echocardiography and cardiac markers in predicting the occurrence of LVT compared with a reference cardiac imaging (DE-CMR) and to determine the risk of systemic embolization to the CNS using brain MRA. METHODS: Seventy patients after MI managed by percutaneous coronary intervention (localization: 92.9% anterior wall, 7% other; median age 58.7 years) were initially examined by transthoracic echocardiography (TTE, n=69) with a focus on LVT detection. Patients were then referred for DE-CMR (n=55). Laboratory determination of cardiac markers (Troponin T and NTproBNP) was carried out in all. Brain MRA was performed 1 year apart (n=51). RESULTS: The prevalence of LVT detected by echocardiography: (n=11/69, i.e. 15.9%); by DE-CMR: (n=9/55, i.e. 16.7%). Statistically significant parameters to predict the occurrence of LVT after AMI (cut off value): (a) detected by echocardiography: anamnestic data - delay (≥ 5 hours), echocardiographic parameters - left atrial volume index (LAVI≥ 32 mL/m2), LV EF Simpson biplane and estimated (≤ 42%), tissue Doppler determination of septal A wave velocity (≤ 7.5cm/s); (b) detected by DE-CMR: anamnestic data - delay (≥ 13 hours), DE-CMR parameters - left ventricular end-diastolic diameter (≥ 54mm). The value of cardiac markers (Troponin T and NTproBNP in ng/L) in LVT detected by echocardiography did not reach statistical significance. In LVT detected by DE-CMR, NTproBNP was statistically significantly increased at 1 month after AMI onset (no optimal cut-off value could be determined). There was no statistically significant association between the LVT detection (both modalities) and the occurrence of clinically manifest and silent cardioembolic events. CONCLUSION: Our study confirmed a relatively high prevalence of LVT in the high-risk group of patients with anterior wall STEMI. Due to the low prevalence of thromboembolic complications, no significant association between the LVT detection and the occurrence of a cardioembolic event was demonstrated.

Cardiac device-related infective endocarditis in the Czech Republic: Prospective data from the ESC EORP EURO-ENDO registry.

AIM: Understanding cardiac electronic device infective endocarditis epidemiology is essential for the management of this serious complication. Only monocentric and limited data have been published regarding patients in the Czech republic so far. The aim of this study was to describe the current profile, microbiology and clinical characteristics of this population. PATIENTS AND METHODS: National data from the prospective ESC-EORP EURO-ENDO registry were collected. 57 consecutive patients with a diagnosis of cardiac device-related infective endocarditis (CDRIE) from 11 Czech centres were included. RESULTS: Staphylococcus spp. was responsible for 43.9% of isolates, whereas Culture negative endocarditis was documented in 26.3% episodes. The most frequent complications under therapy were acute renal failure (17.5%), septic shock and heart failure (both 10.5%). Extraction of device was performed in 75.4% of all patients, and the 1-year mortality was 22.5%. CONCLUSIONS: The high proportion of culture-negative endocarditis is alarming and warrants further investigation. Cardiac device related infective endocarditis is a serious complication with a high 1-year mortality in a highly polymorbid spectrum of patients.

Risk of recurrent ischemic stroke in young cryptogenic patients with embolic stroke of undetermined source.

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 ±â€¯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.

Acute myocardial infarction, intraventricular thrombus and risk of systemic embolism.

The development of left ventricular thrombus (LVT) is a well-known and serious complication of acute myocardial infarction (AMI) due to the risk of systemic arterial embolism (SE), which is variable in its clinical picture and has potentially serious consequences depending on the extent of target organ damage. SE results in an increase in mortality and morbidity in these patients. LVT is one of the main causes of the development of ischaemic cardio-embolic cardiovascular events (CVE) after MI and the determination of the source of cardiac embolus is crucial for the initiation of adequate anticoagulant therapy in secondary prevention. Echocardiography holds an irreplaceable place in the diagnosis of LVT, contrast enhancement provides higher sensitivity. The gold standard for LVT diagnosis is cardiac magnetic resonance imaging, but it is not suitable as a basic screening test. In patients with already diagnosed LVT, it is necessary to adjust antithrombotic therapy by starting warfarin anticoagulation for at least 6 months with the need for echocardiographic follow-up to detect thrombotic residues. The effect of prophylactic administration of warfarin in high-risk patients after anterior AMI does not outweigh the risk of severe bleeding complications and does not result in a decrease in mortality and morbidity. At the present time, there is not enough evidence to use direct oral anticoagulants in this indication.