The Device for Communication in the Tool for Measurement in Boreholes

In this paper an implementation and test of the device for communication between Telemetry system and Surface unit with the tool for measurement of pipe diameter, fluid velocity and direction of flow in the borehole (Calliper-Fullbore Flowmeter - CFF) are presented. This communication is done according to SIPLOS (Simultaneous Production Logging String) protocol and it is used by Hotwell company [1] as a part of a larger system for borehole investigations

Perception of surgical complications among patients, nurses and physicians: a prospective cross-sectional survey

BACKGROUND: Several scores grade the severity of post-operative complications but it is unclear whether such scores truly reflect the perception of patients and practicing nurses and physicians. Study design: 227 patients, 143 nurses and 245 physicians independently rated the severity of 30 common post-operative complications on a numerical analogue scale from 0 (not severe at all) to 100 (extremely severe) while being blinded towards the Clavien-Dindo classification. We considered a difference in ratings of >10 to be clinically important in distinguishing between grades of severity and groups. We evaluated the level of reproducibility of responses by calculating intraclass correlation coefficients (ICC) and compared scores across severity grades and between groups using the generalized estimating equations. RESULTS: Reproducibility of the ratings was good for all three groups (ICCpatients 0.71 (95%-CI 0.64-0.76), ICCnurses 0.83 (0.78-0.87) and ICCphysicians 0.87 (0.83-0.90)). The participants' perceptions of the severity of complications reflected the Clavien-Dindo classification (median of grade I: 20 (IQR 10-30), grade II: 40 (31.3-52.5), grade IIIa: 50 (40-60), grade IIIb: 70 (60-75), grade IVa: 85 (80-90) and grade IVB: 95 (90-100)). Although patients' perception differed significantly from those of physicians (average difference -8.7 (95%-CI -10.4 to -6.9, p<0.001) and nurses (difference -2.8 (-4.8 to -0.8, p=0.007) they did not reach our thresholds for clinical importance. CONCLUSION: The severity of post-operative complications is perceived similarly by patients, nurses and physicians and reflects the Clavien-Dindo classification well. Our results support the use of Clavien-Dindo classification system as part of the shared or informed decision making process

Effects of six-month creatine supplementation on patient- and clinician-reported outcomes, and tissue creatine levels in patients with post-COVID-19 fatigue syndrome

Dietary creatine has been recently put forward as a possible intervention strategy to reduce post-COVID-19 fatigue syndrome yet no clinical study so far evaluated its efficacy and safety for this perplexing condition. In this parallel-group, randomized placebo-controlled double-blind trial, we analyzed the effects of 6-month creatine supplementation (4 g of creatine monohydrate per day) on various patient- and clinician-reported outcomes, and tissue creatine levels in 12 patients with post-COVID-19 fatigue syndrome. Creatine intake induced a significant increase in tissue creatine levels in vastus medialis muscle and right parietal white matter compared to the baseline values at both 3-month and 6-month follow-ups (p < .05). Two-way analysis of variance with repeated measures revealed a significant difference (treatment vs. time interaction) between interventions in tissue creatine levels (p < .05), with the creatine group was superior to placebo to augment creatine levels at vastus medialis muscle, left frontal white matter, and right parietal white matter. Creatine supplementation induced a significant reduction in general fatigue after 3 months of intake compared to baseline values (p = .04), and significantly improved scores for several post-COVID-19 fatigue syndrome-related symptoms (e.g., ageusia, breathing difficulties, body aches, headache, and difficulties concentrating) at 6-month follow-up (p < .05). Taking creatine for 6 months appears to improve tissue bioenergetics and attenuate clinical features of post-COVID-19 fatigue syndrome; additional studies are warranted to confirm our findings in various post-COVID-19 cohorts.publishedVersio

Characterization of nanostructured spinel NiFe2O4 obtained by soft mechanochemical synthesis

Powdery nickel ferrite, NiFe2O4 has been obtained by soft mechanochemical synthesis in a planetary ball mill. Ni(OH)2 and Fe(OH)3 are used as initial compounds. This mixture was mechanically activated for 25h, uniaxial pressed and sintered at 1100°C for 2h. The phase composition of the sintered sample was analyzed by X-ray diffraction (XRD), energy dispersive spectrometer (EDS) and Raman spectroscopy. Morphologies were examined by scanning electron microscopy (SEM). The electrical DC/resistivity/conductivity at different temperatures was measured using a Source Meter Keithley 2410. An Impedance/Gain-Phase Analyzer (HP-4194) was used to measure the impedance spectra (100Hz - 10MHz) at different temperatures. [Projekat Ministarstva nauke Republike Srbije, br. III 45003 i br. III 45015

Aortic stent-grafting: successful introduction into the combined procedure for coronary artery bypass grafting and aortic aneurysm repair

Objectives: Coronary artery bypass grafting (CABG) and combined stent-grafting (SG) were evaluated to reduce morbidity and mortality of patients with descending or infrarenal aortic aneurysm. Methods: CABG and SG (thoracic n=6, infrarenal n=36) were performed during the same hospitalization in 42 patients (mean age of 73±14 years). In 29 patients (mean Euroscore: 9), SG was performed under local anesthesia 9±3 days after coronary surgery (simultaneous) and in 13 patients (mean Euroscore: 7) during the same anesthesia (synchronous). In the latter group, 11 out of 13 patients underwent off-pump CABG. All aneurysms were treated by implantation of commercially available self-expanding grafts. Results: CABG was successful in all, but one patient with left internal mammary artery hypoperfusion syndrome, requiring an additional distal saphenous graft to the left anterior descending coronary artery. SG was uneventful in 98% (41/42 patients). Postoperative computerized tomography showed incomplete sealing in seven patients (17%), but only the two attachment endoleaks had to be treated by one proximal and one distal SG extension. Overall hospital stay for the synchronous repair was 12.5±6 days and that of the simultaneous group 17.5±7 days. Thirty-day mortality was 5% (2/42) as one patient of the simultaneous group experienced a lethal cerebral embolism during SG and one patient of the synchronous group developed an untreatable infection. In the follow-up of 4 years, there were two vascular reinterventions but no additional procedure-related morbidity or mortality. Conclusions: This experience shows that combined CABG and SG of thoracic or infrarenal aortic aneurysm is a safe and less-invasive alternative to the open graft repair, especially in the older patients or patients with severe comorbiditie

Simple and Low-cost Fiber-optic Sensors for Detection of UV Radiation

In this paper two simple and low-cost fiberoptic sensors for detection of UV radiation are presented. A U-shaped sensor covered with an UV marker for UV radiation detection and a fiber-optic sensor with one end covered with powder from a mercury lamp are produced and described in details. Both sensors are made of large-core PMMA plastic optical fibers. As UV sources, a solar simulator and four different UV lamps are used. The light spectrum on the fiber output is measured by using an USB spectrometer. Dependence of output light intensity on the distance of end-type sensor with powder from a mercury lamp from UV lamp is investigated as well. On the output of the sensor covered with powder from a mercury lamp are obtained peaks of fluorescent emission at approximately 616 nm and 620 nm wavelengths

Prediktori ranog nastupa depresije nakon moždanog udara

Post-stroke depression (PSD) is a severe and frequent stroke complication and one of the crucial factors for the outcome of rehabilitation and life quality after stroke. However, mood disorders frequently remain unnoticed and therefore untreated. The aim of the study was to examine all the potential risk factors and determine the independent predictors of early-onset depression after first-ever stroke, which would help identify high-risk patients, establish early diagnosis and timely treatment that would improve the course and prognosis of this disorder. This prospective study included 60 patients treated for their first-ever stroke; there were 30 patients diagnosed with depression and 30 patients without depression. The study included collection and analysis of all socio-demographic and clinical risk factors for PSD. Testing was performed two weeks after stroke. Depression was diagnosed according to the Mini International Neuropsychiatry Interview, DSM-IV diagnostic criteria, and depression severity was quantified by the Hamilton Depression Rating Scale. Cognitive impairment was assessed by the Mini Mental State Examination. Neurological deficit was assessed by the US National Institute of Health Stroke Scale. Our results showed that the independent predictors of early-onset depression after stroke were previous depressive episodes, cognitive dysfunction, and more severe neurological deficit.Depresija nakon moždanog udara je teška i česta komplikacija moždanog udara i jedan od ključnih čimbenika za ishod rehabilitacije i kvalitetu života nakon moždanog udara. Međutim, poremećaji raspoloženja ostaju najčešće neprepoznati, a samim tim i neliječeni. Cilj ovoga istraživanja bio je ispitati sve potencijalne čimbenike rizika i utvrditi nezavisne prediktore depresije koja se javlja rano nakon moždanog udara, a koji bi omogućili identifikaciju visokorizičnih bolesnika, postavljanje rane dijagnoze i pravodobno liječenje, što bi unaprijedilo tijek i prognozu ove bolesti. Prospektivno istraživanje obuhvatilo je 60 bolesnika liječenih zbog klinički prvog moždanog udara, od toga 30 bolesnika s dijagnosticiranom depresijom i 30 bolesnika bez depresije. Istraživanje je obuhvatilo podatke o svim socio-demografskim i kliničkim čimbenicima rizika za nastanak depresije nakon moždanog udara. Testiranja su provedena dva tjedna nakon moždanog udara. Depresija je dijagnosticirana prema Mini International Neuropsychiatry Interview, DSM-IV dijagnostičkim kriterijima, težina depresije kvantificirana je Hamiltonovom ljestvicom za procjenu depresivnosti (HDRS). Kognitivni status procjenjivao se pomoću Mini Mental State Examination (MMSE). Neurološki status se procjenjivao pomoću Ljestvice za moždani udar Nacionalnog instituta za zdravlje, SAD (NIHSS). Rezultati našega istraživanja ukazuju na to da su nezavisni prediktori ranog nastupa depresije nakon moždanog udara ranije depresivne epizode, kognitivne disfunkcije i teži neurološki deficit

Intrinsic resistivity of sintered nickel manganite vs. powder activation time and density

Poster presented at the conference Fizika i tehnologija materijala (Physics and Technology of Materials), FITEM '07, Čačak, Serbia, August 6-8, 2007.Paper: [https://hdl.handle.net/21.15107/rcub_dais_208]Final results were published in the article [http://dx.doi.org/10.2298/SOS0801027S

Structural and electrical properties of Ti doped α-Fe2O3

In this work we have analyzed the effects of Ti doping on structural and electrical properties of α-Fe2O3. When the amount of added Ti (5 wt.%TiO2) was within the solubility degree and XRD, SEM and EDS analysis revealed a homogenous hematite structure, with lattice parameters a= 5.03719(3) Å, c=13.7484(1) Å slightly increased due to incorporation of Ti into the rhombohedral hematite lattice. Higher amounts of Ti (10 wt.%TiO2) resulted in the formation of pseudobrookite, besides hematite, confirmed by SEM and EDS analysis. Studies of electric properties in the temperature range 25-225oC at different frequencies (100 - 1Mz) showed that Ti doping improved electrical conductivity. Impedance analysis was performed using an equivalent circuit, showing one relaxation process and suggesting dominant grain boundary contribution. [Projekat Ministarstva nauke Republike Srbije, br. III45014 i br. III43008

Influence of Bi2O3 on microstructure and electrical properties of ZnO-SnO2 ceramics

The effects of small amounts (0.5; 1.0 and 1.5 mol. %) of bismuth oxide on the microstructure and electrical properties of ZnO-SnO2 ceramics have been studied. Starting powders of ZnO and SnO2 were mixed in the molar ratio 2:1. After adding Bi2O3 this mixture was mechanically activated for 10 minutes in a planetary ball mill, uniaxially pressed and sintered at 1300ºC for 2h. The phase composition of the sintered samples was analyzed by X-Ray Diffraction (XRD) and by Energy Dispersive Spectrometer (EDS). Morphologies were examined by Scanning Electron Microscopy (SEM). An Impedance/Gain Phase Analyzer (HP 4194A) was used to measure the impedance spectra (100Hz - 10MHz) at different temperatures. The electrical DC resistivity/conductivity at different temperatures was measured using a High Resistance Meter (HP 4329A)