44 research outputs found
Morphology and digitally aided morphometry of the human paracentral lobule
The human paracentral lobule, the junction of the precentral and postcentral gyri at the medial hemispheric surface, contains several important functional regions, and its variable morphology requires exact morphological and quantitativedata. In order to obtain precise data we investigated the morphology of the paracentral lobule and quantified its visible (extrasulcal) surface. This surface corresponds to commonly used magnetic resonance imaging scout images. We studied84 hemispheres of adult persons (42 brains; 26 males and 16 females; 20–65 years) fixed in neutral formalin for at least 4 weeks. The medial hemispheric surface was photographed at standard distance and each digital photo was calibrated.Using the intercommissural line system (commissura anterior-commissura posterior or CA-CP line), we performed standardised measurements of the paracentral lobule. Exact determination of its boundaries and morphological typeswas followed by digital morphometry of its extrasulcal surface using AutoCAD software. We found two distinct morphological types of the human paracentral lobule: continuous type, which was predominant (95.2%), and rare segmented type (4.8%). In hemispheres with segmented cingulate sulcus we also found theshort transitional lobulo-limbic gyrus (13.1%). The mean extrasulcal surface of the left paracentral lobule was significantly larger, both in males (left 6.79 cm2 vs. right 5.76 cm2) and in females (left 6.05 cm2 vs. right 5.16 cm2). However, even larger average surfaces in males were not significantly different than the same in females. Reported morphological and quantitative data will be useful during diagnostics and treatment of pathologies affecting the human paracentral lobule, and in further studies of its cytoarchitectonic and functional parcellations
Još o toksičnosti kadmija - s posebnim osvrtom na nastanak oksidacijskoga stresa i na interakcije s cinkom i magnezijem
Discovered in late 1817, cadmium is currently one of the most important occupational and environmental pollutants. It is associated with renal, neurological, skeletal and other toxic effects, including reproductive toxicity, genotoxicity, and carcinogenicity. There is still much to find out about its mechanisms of action, biomarkers of critical effects, and ways to reduce health risks. At present, there is no clinically efficient agent to treat cadmium poisoning due to predominantly intracellular location of cadmium ions. This article
gives a brief review of cadmium-induced oxidative stress and its interactions with essential elements zinc and magnesium as relevant mechanisms of cadmium toxicity. It draws on available literature data and our own results, which indicate that dietary supplementation of either essential element has beneficial effect under condition of cadmium exposure. We have also tackled the reasons why magnesium addition prevails over zinc and discussed the protective role of magnesium during cadmium exposure. These findings could help to solve the problem of prophylaxis and therapy of increased cadmium body burden.Iako je otkriven tek 1817. godine, kadmij je trenutačno jedan od najvažnijih onečišćivača životne i radne sredine. Štetno djeluje na bubrege, živčani sustav, kosti, reproduktivni sistem, a ima i
genotoksične i karcinogene efekte. Nužna su dalja istraživanja vezana za mehanizme njegove toksičnosti, biomarkere efekata, kao i načine smanjenja rizika za zdravlje. Osim toga, do danas nije otkriven agens efikasan u terapiji trovanja kadmijem s obzirom na to da je kadmij intracelularni kation. U ovom radu dan je sažet pregled važnih mehanizama toksičnosti kadmija, kao što su nastanak
oksidativnog stresa i interakcije s esencijalnim elementima, cinkom i magnezijem, na osnovi dostupnih literaturnih podataka, kao i naših ispitivanja koja upućuju na to da povećani unos navedenih esencijalnih elemenata pokazuje pozitivne efekte pri ekspoziciji kadmiju. Obrazložena je prednost suplementacije magnezijem pred suplementacijom cinkom i razmatrana preventivna uloga magnezija
pri intoksikaciji kadmijem. Ovi su rezultati doprinos rješavanju problema profi lakse i terapije trovanja kadmijem
Urinary metals and metal mixtures and oxidative stress biomarkers in an adult population from Spain: The Hortega Study
INTRODUCTION: Few studies have investigated the role of exposure to metals and metal mixtures on oxidative stress in the general population. OBJECTIVES: We evaluated the cross-sectional association of urinary metal and metal mixtures with urinary oxidative stress biomarkers, including oxidized to reduced glutathione ratio (GSSG/GSH), malondialdehyde (MDA), and 8‑oxo‑7,8‑dihydroguanine (8-oxo-dG), in a representative sample of a general population from Spain (Hortega Study). METHODS: Urine antimony (Sb), barium (Ba), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), molybdenum (Mo), vanadium (V) and zinc (Zn) were measured by ICPMS in 1440 Hortega Study participants. RESULTS: The geometric mean ratios (GMRs) of GSSG/GSH comparing the 80th to the 20th percentiles of metal distributions were 1.15 (95% confidence intervals [95% CI]: 1.03-1.27) for Mo, 1.17 (1.05-1.31) for Ba, 1.23 (1.04-1.46) for Cr and 1.18 (1.00-1.40) for V. For MDA, the corresponding GMRs (95% CI) were 1.13 (1.03-1.24) for Zn and 1.12 (1.02-1.23) for Cd. In 8-oxo-dG models, the corresponding GMR (95% CI) were 1.12 (1.01-1.23) for Zn and 1.09 (0.99-1.20) for Cd. Cr for GSSG/GSH and Zn for MDA and 8-oxo-dG drove most of the observed associations. Principal component (PC) 1 (largely reflecting non-essential metals) was positively associated with GSSG/GSH. The association of PC2 (largely reflecting essential metals) was positive for GSSG/GSH but inverse for MDA. CONCLUSIONS: Urine Ba, Cd, Cr, Mo, V and Zn were positively associated with oxidative stress measures at metal exposure levels relevant for the general population. The potential health consequences of environmental, including nutritional, exposure to these metals warrants further investigation
A fuzzy model for an increase in locomotive traction force
This paper deals with the process of traction force realization described by a suitable mechanical model and is pointed to the adhesion phenomenon as a physical one, i.e. is a suitable factor that the value of traction force depends on. The model for the process of optimizing locomotive traction force based on using the fuzzy set theory is explained. The projecting process of a fuzzy controller regulating the value of skidding and the value of traction torque by increasing the value of traction force that can be realized according to adhesion conditions is described. Finally, testing the optimization model in several numerical examples under specific conditions of wheel-rail adhesion is done
Maksymalizacja siły hamowania za pomocą modelu z logiką rozmytą
This paper shows the process of braking force realization by air brakes with brake shoes accompanied by a suitable mechanical model. The complexity of adhesion nature as a physical phenomenon as well as the limited factors on which the braking force value depends are pointed out. According to this, the model of braking force realization based on the fuzzy set theory is explained. The procedure of fuzzy controller projecting with a task to regulate the value of kidding and by that the value of braking torque through the air pressure in the braking cylinder by maximizing the braking force that can be realized according to adhesion conditions is described. The testing of the optimization model under concrete adhesion conditions of the wheels on the rails is done at the end of the paper.W artykule opisano proces generowania siły hamującej w pneumatycznych hamulcach szczękowych za pomocą odpowiedniego modelu mechanicznego. Szczególny nacisk położono na złożoność natury adhezji jako zjawiska fizycznego oraz ograniczoność czynników, od których zależy wartość siły hamującej. W tym kontekście zbudowano model oparty na logice rozmytej jako teoretyczne narzędzie do określania siły hamowania. Opisano procedurę projektowania sterownika rozmytego, którego zadaniem jest kontrola wartości poślizgu poprzez dobór momentu hamującego wynikającego z ciśnienia w zbiorniku układu pneumatycznego oraz aktualnych warunków adhezji. Na zakończenie przeprowadzono test modelu optymalizującego siłę hamowania dla konkretnych warunków adhezji pomiędzy szyną, a kołem poruszającego się po niej pojazdu
Prevalence of dental caries in hospitalized patients with schizophrenia
© 2016, Institut za Vojnomedicinske Naucne Informacije/Documentaciju. All rights reserved. Background/Aim. It is considered that over 450 million people worldwide suffer from some form of mental disorder. Previous studies in other countries have shown that schizophrenia is among the most frequent. Oral health is significant for general health and should not be separated from mental health. Studies in other countries have shown an increased incidence of carious and extracted teeth, and less incidence of filled teeth in this group of psychiatric patients. The aim of this study was to establish condition of the existing teeth, to determine the prevalence of caries and to consider possible risk factors that contribute to the current oral health status of hospitalized patients with schizophrenia. Methods. The study comprised 190 patients with schizophrenia, hospitalized at the Clinic for Psychiatric Disorders Dr. Laza Lazarević in Belgrade, and 190 mentally healthy patients at the Clinic for Periodontology and Oral Medicine, Faculty of Dental Medicine in Belgrade. The decayed, missing, filled (DMF) index, sociodemographic and economic characteristics were registered in both groups, as well as characteristics of the primary disease of hospitalized patients with schizophrenia. Results. The value of DMF index (representing the sum of carious, extracted and filled teeth), in the hospitalized patients with schizophrenia was 18.57 ± 7.07 and 12.47 ± 5.64 in the healthy group (p = 0.000). The structure of the DMF index in the study group showed that caries and extracted teeth dominated with 88.1%; in the control group, filled teeth dominated with 55.6%, which was a statistically significant difference for all the three observed variables. Conclusion. Hospitalized patients with schizophrenia had twice as many caries and extracted teeth, and five time less filled teeth than healthy people. The patient’s age and taking antiparkinsonics were established as predictors of the increased DMF index in hospitalized patients with schizophrenia
Study of Stress-Annealing Enhancement of Magnetoimpedance Effect in Metallic Glass Ribbons
In this study, the magnetoimpedance effect in magnetically soft metallic glass ribbon samples with significant decrease in atomic percentage of metalloids content (less than 10 at.%) was investigated. Thermal treatments were performed by stress-annealing technique of up to 693 K/475 MPa/30 min. The critical frequency of about 600 kHz was observed as the point with the initial increase in magnetoimpedance ratio. Significant improvement of magnetoimpedance-response reaching the value ΔZ/Z=25% after stress-annealing at 693 K/130 MPa/30 min was recorded in samples with still amorphous structure at driving frequency of 4 MHz. The highest magnetoimpedance-element sensitivity was found for low magnetic field intensity (H ≤ 1 kA/m), where values of about 12%/kA/m were attained
Influence of nickel in soil
The objective of this investigation has been to study consequences of soil pollution with nickel in five locations in the municipalities of Sremska Kamenica, Ledinci and Beocin. The analysis of soil samples
collected in the five locations has shown that the percentage of nickel differed from location to location. Nickel contamination was registered in 60% of the analyzed sites. A possible nickel polluter in this area is the cement factory in Beocin (CFB). The intensity of nickel contamination of soil decreased progressively
with the distance of the sampling sites from the cement factory in Beocin