Influence of mechanical activation on microstructure and crystal structure of sintered MgO-TiO2 system

Mixtures of MgO-TiO2 were mechanically activated using high-energy planetary ball mill during 5, 10, 20, 40, 80 and 120 minutes. Sintering process was preformed in air at 1100°-1400°C for 2h. The decrease in powder's particle size was noticed as the time of mechanical activation increased and confirmed by particle size analyzer. XRD analyses were performed in order to acquire the information about phase composition. Different ratio mixtures of MgTiO3 and Mg2TiO4 are present within all sintered samples. The effect of tribophysical activation on microstructure was investigated by scanning electron microscopy. The differential thermal gravimetric analysis has been performed in order to investigate thermal behaviour of the mixtures.Smeše MgO-TiO2 su mehanički aktivirane u visoko-energetskom planetarnom mlinu tokom 5, 10, 20, 40, 80 i 120 minuta. Fazni sastav je određen rendgenskom difrakcijom. Sa porastom vremena mlevenja, primećeno je smanjenje veličine čestica praha. Takođe, ispitan je i efekat tribofizičke aktivacije na mikrostrukturu praha metodom skenirajuće elektronske mikroskopije. Radi ispitivanja termičkih svojstava praha, urađena je diferencijalna termijska analiza. Proces sinterovanja izveden je u vazduhu u temperaturnom opsegu od 1100°-1400°C tokom 2 sata. U svim sinterovanim uzorcima uočeno je prisustvo dve faze MgTiO3 i Mg2TiO4 ali njihov međusobni odnos koncentracija varira u odnosu na temperaturu sinterovanja

The Effect of Liquid-Phase Exfoliated Graphene Film on Neurodifferentiation of Stem Cells from Apical Papilla

Background: Dental stem cells, which originate from the neural crest, due to their easy accessibility might be good candidates in neuro-regenerative procedures, along with graphene-based nanomaterials shown to promote neurogenesis in vitro. We aimed to explore the potential of liquid-phase exfoliated graphene (LPEG) film to stimulate the neuro-differentiation of stem cells from apical papilla (SCAP). Methods: The experimental procedure was structured as follows: (1) fabrication of graphene film; (2) isolation, cultivation and SCAP stemness characterization by flowcytometry, multilineage differentiation (osteo, chondro and adipo) and quantitative PCR (qPCR); (3) SCAP neuro-induction by cultivation on polyethylene terephthalate (PET) coated with graphene film; (4) evaluation of neural differentiation by means of several microscopy techniques (light, confocal, atomic force and scanning electron microscopy), followed by neural marker gene expression analysis using qPCR. Results: SCAP demonstrated exceptional stemness, as judged by mesenchymal markers’ expression (CD73, CD90 and CD105), and by multilineage differentiation capacity (osteo, chondro and adipo-differentiation). Neuro-induction of SCAP grown on PET coated with graphene film resulted in neuron-like cellular phenotype observed under different microscopes. This was corroborated by the high gene expression of all examined key neuronal markers (Ngn2, NF-M, Nestin, MAP2, MASH1). Conclusions: The ability of SCAPs to differentiate toward neural lineages was markedly enhanced by graphene film

Novi trendovi u neuromonitoringu bolesnika sa aneurizmalnom subarahnoidnom hemoragijom

Neurointensive care of patients with subarachnoid haemorrhage is based on the theory that clinical outcome is the consequence of the primary haemorrhage and a number of secondary insults in the acute post haemorrhage period. Several neuromonitoring techniques have been introduced or accomplished into clinical practice in the last decade with the purpose of monitoring different but related aspects of brain physiology, such as cerebral blood flow (CBF), pressure within the cranial cavity, metabolism, and oxygenation. The aim of these techniques is to obtain information that can improve knowledge on brain pathophysiology, and especially to detect secondary insults which may cause permanent neurological damage if undetected and untreated in 'real time', at the time when they can still be managed. These techniques include intracranial pressure (ICP) measurements, jugular venous oxygen saturation, near-infrared spectroscopy, brain tissue monitoring, and transcranial Doppler. The available devices are limited because they measure a part of complex process indirectly. Expense, technical difficulties, invasiveness, limited spatial or temporal resolution and the lack of sensitivity add to the limitation of any individual monitor. These problems have been partially addressed by the combination of several monitors known as multimodality monitoring. In this review, we describe the most common neuromonitoring methods in patients with subarachnoidal hemorrhage that can assess nervous system function, cerebral haemodynamics and cerebral oxygenation.Neurointenzivna nega bolesnika sa subarahnoidnom hemoragijom bazira se na shvatanju da klinički oporavak zavisi od primarne hemoragije i brojnih sekundarnih oštećenja u akutnom post hemoragijskom periodu. Nekoliko novih tehnika neuromonitoringa počelo se primenjivati, ili je usavršeno u kliničkoj praksi, u poslednjoj dekadi sa namerom praćenja različitih ali povezanih aspekata moždane fiziologije, kao što su cerebralni krvni protok, pritisak unutar kranijuma, cerebralni metabolizam i cerebralna oksigenacija. Cilj ovih tehnika je da se poboljšaju znanja iz moždane patofiziologije, i posebno da se otkriju sekundarni poremećaji koji mogu da dovedu do trajnih neuroloških oštećenja ako se na vreme ne otkriju i ne tretiraju. Ove tehnike obuhvataju kontinuirano merenje intrakranijalnog pritiska, monitoring jugularne venske oksimetrije, near-infrared spectroscopiju, monitoring cerebralnog tkiva i transkranijalni Doppler. Raspoložive metode su limitirane jer mere indirektno samo deo kompleksnih cerebralnih funkcija. Skupoća merenja, tehnička složenost, invazivnost, limitiranost prostorom i vremenom primene, mala osetljivost predstavljaju limitirajuće faktore svake pojedinačne metode. Ovi problemi se mogu delimično rešiti kombinacijom nekoliko metoda merenja, što je poznato kao multimodalitetni monitoring. U ovom radu razmatraju se najčešće primenjene metode monitoringa za procenu funkcije nervnog sistema, cerebralne hemodinamike i cerebralne oksigenacije

Parathyroid dual tracer subtraction scintigraphy: small regions method for quantitative assessment of parathyroid adenoma uptake.

OBJECTIVE: The aim was quantitative assessment of parathyroid adenoma (PTA) uptake in dual tracer dynamic scintigraphy. METHODS: In 78 patients, median age 58 (19-80) years, surgically treated for primary hyperparathyroidism (PHPT), with parathyroid hormone median 125 (70-658) pg/ml, we performed preoperative parathyroid scintigraphy, following EANM guidelines of subtraction and double-phase protocol (2009) using two tracers: Tc-99m pertechnetate and Tc-99m MIBI. In addition to standard subtraction processing and visual interpretation of delayed MIBI planar images of neck and mediastinum in oblique sections (positions according to ultrasound PTA localisation), we developed Submarine processing software that enables selecting custom regions grid sizes ≥6 mm (as this solution was not present in commercial software) to follow time activity curve changes in thyroid tissue and PTA. Histopathology in 53/78 patients revealed PHPT and in 25/78 patients thyroid nodular disease only, and thyroid malignancy occurred in total of 15/78 (19 %) patients. PHPT group included 44 solitary PTA, 8 patients with hyperplasia and one parathyroid carcinoma. The median macroscopic volume of PTA was 717.5 (15-6125) mm(3). Concomitant PHPT and thyroid nodular disease occurred in 24/53 patients and among them 8 patients had thyroid malignancies. RESULTS: PTA showed typical pattern of late peak on time activity curves characterized by median start time on 15 (10-25) min, the peak amplitude mean 19 (±5) % above thyroid declining washout curve, and duration of peak 6 (4-10) min, allowing PTA to "emerge" like submarine, independent from thyroid tissue and lesions. The ratio of PTA-to-normal thyroid uptake at peak maximum was 1.35 (±0.21). The thyroid TACs results of normal 29/78 (37 %) patients, benign nodular 34/78 (44 %) patients, and malignancy in 15 (19 %) patients were all presented by declining exponential curves. The slope analysis of TACs in normal thyroid tissue, thyroid benign and malignant lesions (linear fitted logarithm of TAC) showed no difference (the same negative slope: -0.04). Submarine processing was sensitive in detection of small lesions, in hyperplasia, and concomitant thyroid nodular disease. CONCLUSIONS: The novel Submarine processing confirmed specific PHPT pattern and was effective in the group with potential pitfalls of standard interpretation, increasing sensitivity and specificity of standard processing subtraction algorithm. Prolonged MIBI accumulation was present in malignant as well as benign thyroid nodules with identical TAC slope

Razlika u vrednostima gasnih analiza arterija i unutrašnje jugularne vene kod bolesnika sa infarktom mozga

Introduction. Cerebral infarction is more and more frequently present by massive participation and high percentage of mortality even in young population. It is notified as very hard, vitally endangered disease. Objective. To prove whether there is a difference in the gas analyses of the arterial and cerebral venous blood between the patients with the cerebral infarction of the left and right hemisphere and why it is significant for the treatment of those patients. Material and methods. Sixty-five (65) patients of both sexes who were diagnosed by CT as: cerebral infarction, cerebral multiinfarctions and cerebral haemorrhagic infarctions were investigated. Under the same conditions their radial artery and left and right internal jugular vein were tapped - on the fourth, eighth and tenth day of their disease. Gas analysis, calculation of oxygen content and statistical comparison of testing results were performed from the samples of arterial and venous blood. Results. By continuous monitoring of gas analysis parameters of arterial and cerebral venous blood from internal jugular vein, we can follow up the phases of disease, the velocity of changes of gas analysis parameters and adequacy of brain circulation and to correct therapy adequately for the purpose of preventing basic disease complications and to estimate the results of treatment. Conclusion. There is a significant difference between the results of gas analysis of arteries and the internal jugular vein, in patients with infarctions of the left and right hemisphere of the brain.Uvod. Infarkti mozga su sve češće zastupljeni i kod mlađe populacije. Praćeni su visokim procentom mortaliteta. Zato ih svrstavamo u teška, vitalno ugrožavajuća oboljenja. Cilj rada. Dokazati da li postoji terapijski značajna razlika u gasnim analizama arterijske i venske krvi (unutrašnje jugularne vene), kod infarkta leve i desne hemisfere mozga. Metod rada. Ispitivano je 65 bolesnika, oba pola, koji su imali dijagnozu verifikovanu kompjuterizovanom tomografijom (CT): infarkt, multiinfarkti i hemoragijski infarkti mozga. Pod jednakim uslovima punktirane su im: arteria radialis, leva i desna unutrašnja jugularna vena - četvrtog, osmog i desetog dana bolesti. Iz uzoraka arterijske i venske krvi rađene su gasne analize i izračunavan sadržaj kiseonika. Rezultati su međusobno upoređivani i obrađivani odgovarajućim statističkim metodama. Rezultati. Kontinuiranim praćenjem parametara gasnih analiza arterijske i venske krvi (unutrašnje jugularne vene) uočene su različite faze bolesti, brzina promene parametara gasnih analiza, stepen adekvatnosti moždane cirkulacije - to sve pomaže u korigovanju terapije, prevenciji komplikacija osnovne bolesti i procenjivanju ishoda lečenja. Zaključak. U gasnim analizama arterija i unutrašnje jugularne vene kod bolesnika sa infarktom leve i desne hemisfere mozga postoji značajna razlika

One-step preparation of gold nanoparticles - exfoliated graphene composite by gamma irradiation at low doses for photothermal therapy applications

Graphene is an excellent material to anchor metal nanoparticles due to its large surface area. In this paper, we report the use of electrochemically exfoliated graphene as support to anchor gold nanoparticles (Au NPs). Au NPs are synthesized via the reduction of chloroauric acid under gamma irradiation at low doses of 1, 5, and 10 kGy and directly deposited onto the graphene surface, making this procedure simple and fast. Good water dispersibility of exfoliated graphene, due to the presence of oxygen-containing functional groups in the structure of graphene, provides long-term stability of Au NPs - graphene composite dispersions. The majority of the Au NPs obtained by this method have sizes of up to 40 nm, while the increase in the applied dose leads to an increase in the amount of smaller nanoparticles. The increase of temperature of the prepared composite material upon irradiation with an 808 nm continuous wave laser was monitored. All samples show a temperature increase between 21.5 and 25.6 °C for 10 min of the laser exposure, which indicates that Au NPs - graphene composite can effectively be used in photothermal treatment for cancer therapy

Potential urban–rural differences in cardiorespiratory fitness and BMI in Serbian schoolchildren

Cardiorespiratory fitness (CRF) represents an essential health-related physical fitness component most frequently assessed by Shuttle-run test (SRT). The aim of this study was to investigate potential differences in CRF between schoolchildren from urban and rural areas, with respect to their age and gender. Data for this part of study were derived from a broad national cross-sectional school-based study aimed to evaluate physical fitness and overweight/obesity prevalence. The study consisted of two parts: the pilot study that was conducted in national capital and vicinity and the national study that included schoolchildren from territory of Republic of Serbia. For the purpose of the pilot study, 2230 schoolchildren (boys n = 1163, girls n =1067, age 9 to 14 years) from urban (3) and rural primary schools (4) were included in the study. Afterwards, the study was expanded on the territory of the Republic of Serbia. For that purpose, 11607 primary schoolchildren (boys n = 5913 and girls n = 5694, age 9 to 14 years) from urban (n = 44) and rural schools (n = 54) were included in the study. All measurements were conducted during regular physical education classes. In addition to time in SRT, basic anthropometric measures were taken (body height (BH), body weight (BW) and body mass index (BMI)). Age, gender and school location interaction associated differences in SRT were examined. Schoolchildren living in the urban area of the national capital had significantly higher BH and BW than their rural peers (there was no difference in BMI between these groups). Regarding the SRT, it was gender- and age-dependent (p < 0.001). Rural schoolchildren had longer time on SRT than urban only in 3rd and 4th- grade (p < 0.001), while in higher grades no difference was observed. The results from the national study showed that urban schoolchildren from Republic of Serbia had higher BH, BW and BMI than their rural peers. Boys had better results in SRT which increased with age (p < 0.001). SRT data revealed that 3rd- grade schoolchildren (regardless of gender) from rural schools achieved better results than their urban peers, contrary to the results from 6th- and 7th- graders. Urban-rural differences in BMI were observed only for schoolchildren participating in the national study. Schoolchildren from rural area of the national capital generally had better cardiorespiratory fitness than their peers from urban area of the national capital, but those differences were mostly age and gender associated. The national study yielded results that were only partly similar to the results from the pilot study. CRF was strongly influenced by age and gender, while area of residence had small impact on CRF. Rural schoolchildren had better CRF in lower grades however due to potential influence of factors other than the area of residence (participation in organized physical activity, lifestyle, eating habits) urban schoolchildren had better levels of CRF in higher grades. © 2016 by Nova Science Publishers, Inc. All rights reserved

Effect of dietary fat level on body dimensions and weight gain of carp

The aim of this study was to investigate the impact of different level of fat in diets on body dimensions and weight gain of carp fry. Fish diets contained 38% protein and 8,12 or 16% of fat. The experiment was carried out in triplicates, (3 tanks per treatment, 9 tanks in total) for 90 days at the Laboratory for Fish Nutrition, at the University of Belgrade, Faculty of Agriculture. Every tank has a usable volume of 120 gallons of water and water flow of 0.34 Lmin-1. After adjusting fish to laboratory conditions, every tank was stocked with 29 fish, average weight 15.4 g. Based on data of body length and height of fish, obtained in 30- to daily intervals, statistical analysis showed that there were differences among fish from different treatments. Fish fed diets with 8% fat achieved 46.8% higher weight gain than fish fed with food containing 12% fat and 65.4% higher weight gain than fish fed with feed containing 16% fat. Additionally, fish fed with less fat in diet had a more elongated body form and less pronounced body height as well as lower values for fish condition. Based on obtained results, it can be concluded that the diet with lower level of fat is justifiable to use, both from an economic and consumer perspective

Importance of zooplankton as live feed for carp larvae

Zooplankton is a very important source of natural food for larvae of many aquaculture species. In semi-intensive systems, which are the dominant type of carp production, many fish species feed on both zooplankton and zoobenthos as adults, while larvae and fry rely mostly on zooplankton. It provides them with high quality nutrients and other molecules such as proteolitic enzymes, hormones and growth factors, which support digestive processes in immature larval gut. Larviculture, especially start feeding of early larval stages, appear to be a critical point in fish culturing. However, artificial diets formulated for larvae show poor digestibility. Use of live feed of small dimensions, good nutritive characteristics and locomotion that provides visual stimulus, overcome that problem. Zooplankters commonly used for mass production as live feed for fish larvae are Rotifers (Brachionus plicatilis and B. calyciflorus) and brine shrimp (Artemia salina). Shortly after hatching, carp larvae are transferred to nursing ponds for further rearing. Ponds are previously prepared through agrotechnical measures in order to provide nutrient enrichment and stimulate production. During the first days of exogenous feeding, larvae consume only the smallest zooplankters such as Rotifers and naupliar larvae of Copepods, while later they move on to bigger pray as Cladocerans. However, due to variable environmental conditions, predation, competition or infections in earthen ponds, mortality in nursing ponds is often very high, reaching over 90%. Thereby, modern approach suggests rearing in indoor tanks in controlled systems and use of automatic feeding systems to provide precise portions of zooplankton

Copper-Sulfate Pentahydrate as a Product of the Waste Sulfuric Acid Solution Treatment

The aim of this study is synthesis of copper-sulfate pentahydrate from the waste sulfuric acid solution-mother liquor generated during the regeneration process of copper bleed solution. Copper is removed from the mother liquor solution in the process of the electrolytic treatment using the insoluble lead anodes alloyed with 6 mass pct of antimony on the industrial-scale equipment. As the result of the decopperization process, copper is removed in the form of the cathode sludge and is precipitated at the bottom of the electrolytic cell. By this procedure, the content of copper could be reduced to the 20 mass pct of the initial value. Chemical characterization of the sludge has shown that it contains about 90 mass pct of copper. During the decopperization process, the very strong poison, arsine, can be formed, and the process is in that case terminated. The copper leaching degree of 82 mass pct is obtained using H2SO4 aqueous solution with the oxygen addition during the cathode sludge chemical treatment at 80 A degrees C +/- A 5 A degrees C. Obtained copper salt satisfies the requirements of the Serbian Standard for Pesticide, SRPS H.P1. 058. Therefore, the treatment of waste sulfuric acid solutions is of great economic and environmental interest. DOI: 10.1007/s11663-012-9721-