53 research outputs found

    Nature, life and mind. An essay on the essence

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    Background: Our long-standing scientific work and love to the fine art and nature for many years succeeded in making a unifying description of the three domains, at a time when a high specialisation in science, and even in art, has neglected the necessary entirety. Materials and methods: Some neurons of a rat cerebral cortex were labelled with true blue and photographed under a fluorescent microscope. A monkey brain was sectioned in the axial plane. Several slices of the human motor cortex were stained with cresyl violet. A cerebral hemisphere image was modified, and another image was created in Adobe Photoshop. Results: Some 10 billion years after the Big Bang life appeared on the Earth, reaching its peak with development of the brain. The humans started exploration of the local nature to survive, and the universe for psychological support. The antique philosophers Leucippes, Democritus and Heraclitus were the first to create a unifying atomic theory and to suggest the eternal movement of the matter. Newton and Kepler explained the movement of the celestial objects, whereas Einstein, Planck, Bohr, Hubbel, Howking and many others connected the quantum physics and elementary forces with the essence of the universe. Leonardo da Vinci, and later many others as well, united science and art. Philosophers and mathematicians created the phenomena which do not exist in nature. Conclusions: Nature designed the human brain, more complex than the universe itself, which in turn created millions of the artworks and scientific discoveries. The might of the mind in some domains overcomes the power of nature

    Značaj veličine i strukture zidova čeonog sinusa na nastanak kontuzije mozga kod traume čeone regije

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    The anatomy of frontal sinus may vary individually, concerning volume and shape differences or, in rare cases, the absence of sinus. However, there are scarce data about the influence of these variations on the structure of fracture, which occurred with the force of a blunt stroke. Therefore, the aim of this study was to analyze the influence of frontal sinus volume on stress distribution and structure of fracture in frontal area. This dissertation studies objective parameters used for evaluation of the size of frontal sinus in condition after the high intensity blunt stroke effect on the appearance of brain contusion. The fracture pattern of trauma is reflected in anterior and/ or posterior wall fractures with or without fractures of nasofrontal canal. The injury of frontal sinus is characterized by a high risk of possible complications, while their management further remains a subject of different attitudes. Dissertation contains epidemiological, experimental and clinical study. Using descriptive method and retrospective study, the epidemiological study inspected the incidence and etiology of fracture of frontal sinus in the Center of Emergency and Neurotrauma – Emergency Center at Clinical Center of Serbia. The cause of fractures of frontal sinus and craniofacial massive injuries is presented, as well as epidemiological and etiological characteristics, clinical parameters and applied surgical procedures for frontal sinus fracture management. All patients placed in trauma department from January 1st 2012 to December 31st 2017 were managed by the same surgeons who were guided by good clinical practice for this type of injury at Clinical Center of Serbia. In accordance with the set goals, the research related to the experimental part of study is conducted in the Laboratory for Numerical Simulations at Bioengineering desk of Faculty of Engineering Sciences, University of Kragujevac. Using computer simulation, the experimental part of the study has analized the voltage distribution and deformation in a complex system of frontal sinus and neurocranium. The study includes four Finite Element skull model representatives. The reference model is made by computerized tomographic scan of human head with normally developed frontal sinuses. Modifying the reference model, there were three additional models generated: a model without sinus, the one with hypoplasia and a model with hyperplastic sinuses. The force of 7,7 kN was applied straightforward on forehead of each model, to simulate the frontal impact. The results show that distribution of force impact in frontal area depends on the volume of frontal sinus. External sinus wall showed the greatest fragility in case of hyperplastic sinus, while posterior wall/ internal plate showed greater fragility in hypoplastic or undeveloped sinus. Well-developed frontal sinuses, through absorption of the impact energy of anterior wall, can protect the posterior wall and intracranial structures. Our results prove that the distribution of stress caused by impacts in frontal region of the head or fracture of bone structures largely depend on the size of the volume of sinus cavity. Well-developed frontal sinuses may have a survival role, acting like „shock absorbers― and protecting intracranial and surrounding vital structures. This study explains for the first time mechanisms of this, previously only assumed – protective role of frontal sinuses. According to the results of clinical study, the main etiological reason for occurrence of the frontal sinus fracture is traffic accident – in particular, the category of co-driver. In our sample, the injury of the frontal sinus is identified at 11,3%. Based on the results, the fracture of sinus wall predict increasing the risk of contusion occurrence by 2,071 times. In case of joint injuries, the risk of contusion occurrence will increase by 1,7 times. The treatment process of this trauma largely depends on complexity and associated injuries, as well as intracerebral conditions which are very common in this type of traumatism

    Uticaj tipa kombajna i vremena ubiranja na kvalitet ubrane kamilice

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    This paper is the result of studying effects of mechanical chamomile harvesting on yield and quality of harvested chamomile. Chamomile (Chamomilla recutita (L) Rausch.) was harvested at three time intervals (T1 - 240 days, T2 - 250 days and T3 - 260 days after sowing) by three conceptually different harvesters. The results achieved indicate that the harvester type significantly influences quality of harvested chamomile, whereas it is not influenced by chamomile harvesting time. Quality of harvested chamomile was classified into four categories, and it was observed that the greater number of rotations of a picking device increased the content of the first category of quality. The harvester A achieved 54.79% of the first category of quality in respect to the harvester B achieving 50.26% and the harvester C with 42.93%.Ovaj rad predstavlja rezultat istraživanja u okviru koga su praćeni efekti mehanizovanog ubiranja na prinos i kvalitet ubrane kamilice. Kamilica je ubirana u tri različita vremenska intervala (T1 - 240 dana, T2 - 250 dana i T3 - 260 dana nakon setve) sa tri koncepcijski različita kombajna. Ostvareni rezultati ukazuju da tip kombajna ima značajan uticaj na kvalitet ubrane kamilice, dok takav uticaj nije izražen kada se posmatra termin ubiranja kamilice. Kvalitet ubrane kamilice je klasifikovan u 4 kategorije, gde je uočeno da veći broj obrtaja beračkog uređaja povećava učešće I kategorije kvaliteta. Kombajn A ostvaruje 54,79% I kategorije kvaliteta ubrane kamilice u odnosu na kombajn B sa 50,26% i kombajn C sa 42,93%

    Koncentracija laktoferina u mlijeku krava tijekom involucije mliječne žlijezde s različitim bakteriološkim nalazima.

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    Lactoferrin is an iron-binding glycoprotein of the transferrin family, present in high concentrations in secretions from the mammary glands during the involution period, and has antimicrobial ability. To determine lactoferrin concentrations in bovine milk with different bacteriological findings, 151 quarter milk samples were collected on a dairy farm of the Holstein-Friesian breed in Vojvodina, Republic of Serbia. Classical microbiological methods were used for bacteria isolation, and ELISA analysis was used for lactoferrin concentration quantification. The most common isolated bacteria in bovine milk samples were Corynebacterium spp. (32.45%) and coagulase-negative staphylococci (4.64%) with lactoferrin concentrations of 6.0497 ± 1.6774 mg/mL and 5.2961 ± 1.3633 mg/mL, respectively. The lowest mean value of lactoferrin concentration was observed in uninfected quarters and quarters infected with environmental pathogens, while the highest concentration of lactoferrin was in udder quarters infected with Streptococcus agalactiae. One in four milk samples where Staphylococcus aureus was isolated had much lower lactoferrin concentrations (1.1736 mg/mL) than the other three samples (6.2089 ± 0.5016 mg/mL), which requires further research.Laktoferin, glikoprotein koji veže željezo, pripadnik porodice bjelančevina transferin, prisutan je u visokoj koncentraciji u sekretu mliječne žlijezde tijekom involucije i posjeduje antimikrobnu sposobnost. Radi utvrđivanja koncentracije laktoferina u mlijeku krava s različitim bakteriološkim nalazima, prikupljen je 151 pojedinačni uzorak mlijeka na farmi holštajn-frizijske pasmine na području Autonomne pokrajine Vojvodine Republike Srbije. Za identifikaciju bakterija korištene su klasične mikrobiološke metode i ELISA za određivanje koncentracije laktoferina. Najčešće izdvojene bakterije u uzorcima mlijeka krava bile su Corynebacterium spp. (32,45%) s koncentracijom laktoferina 6,0497 ± 1,6774 mg/mL i koagulaza negativni stafilokoki (4,64%) s koncentracijom laktoferina 5,2961 ± 1,3633 mg/mL. Najniža srednja vrijednost koncentracije laktoferina zabilježena je u negativnim četvrtima vimena i četvrtima inficiranim bakterijama iz okoliša, dok je najviša koncentracija laktoferina bila u četvrtima vimena inficiranima vrstom Streptococcus agalactiae. Jedan od četiriju uzoraka mlijeka gdje je bio izdvojen Staphylococcus aureus imao je znatno nižu vrijednost laktoferina (1,1736 mg/mL) od ostala tri uzorka (6,2089 ± 0,5016 mg/mL), što zahtijeva daljnja istraživanja

    Magnetic excitations and electronic interactions in Sr2_2CuTeO6_6: a spin-1/2 square lattice Heisenberg antiferromagnet

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    Sr2_2CuTeO6_6 presents an opportunity for exploring low-dimensional magnetism on a square lattice of S=1/2S=1/2 Cu2+^{2+} ions. We employ ab initio multi-reference configuration interaction calculations to unravel the Cu2+^{2+} electronic structure and to evaluate exchange interactions in Sr2_2CuTeO6_6. The latter results are validated by inelastic neutron scattering using linear spin-wave theory and series-expansion corrections for quantum effects to extract true coupling parameters. Using this methodology, which is quite general, we demonstrate that Sr2_2CuTeO6_6 is an almost realization of a nearest-neighbor Heisenberg antiferromagnet but with relatively weak coupling of 7.18(5) meV.Comment: 10 pages, 7 figure

    Study of vacuum and freeze drying of bee honey

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    The aim of this research is to study the drying kinetics of vacuum-dried and freeze-dried bee honey produced from two different varieties: Sunflower honey (Helianthus Annuus L.) and Acacia honey (Robinia pseudo acacia L.). Vacuum drying treatments were carried out with the honey samples' initial temperatures of +25 degrees C, -20 degrees C, and -40 degrees C. Water content, total soluble solids, as well as the water activity of fresh and dried honey samples were determined. Freeze-drying of bee honey with initial sample temperature of -40 degrees C has resulted in shorter drying time (7-9 hours), moisture content (10%-12%), water activity (0.405-0.427 aW) and effective moisture diffusivity coefficient (8.26.10-7-9.51.0-7 m(2)/s). The high-performance liquid chromatography method was used when analyzing the impact that drying pre-treatments had on honey quality. The application of pre-treatments has led to an increase in hydroxy-methyl-furfural by 39-71%, and a decrease in diastase activity by 17-36%, all compared to fresh honey samples. The solutions of Verma model proved to be the best fit with the experimental results

    Study of vacuum and freeze drying of bee honey

    Get PDF
    The aim of this research is to study the drying kinetics of vacuum-dried and freeze-dried bee honey produced from two different varieties: Sunflower honey (Helianthus Annuus L.) and Acacia honey (Robinia pseudo acacia L.). Vacuum drying treatments were carried out with the honey samples' initial temperatures of +25 degrees C, -20 degrees C, and -40 degrees C. Water content, total soluble solids, as well as the water activity of fresh and dried honey samples were determined. Freeze-drying of bee honey with initial sample temperature of -40 degrees C has resulted in shorter drying time (7-9 hours), moisture content (10%-12%), water activity (0.405-0.427 aW) and effective moisture diffusivity coefficient (8.26.10-7-9.51.0-7 m(2)/s). The high-performance liquid chromatography method was used when analyzing the impact that drying pre-treatments had on honey quality. The application of pre-treatments has led to an increase in hydroxy-methyl-furfural by 39-71%, and a decrease in diastase activity by 17-36%, all compared to fresh honey samples. The solutions of Verma model proved to be the best fit with the experimental results

    First cobalt complexes with methyl pyruvate semi/thiosemicarbazone - synthesis, physico-chemical and structural characterization

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    In the reaction of acetone solutions of CoX2∙nH2O (X = Cl, Br) with methyl pyruvate semi/thiosemicarbazone (Hmps, Hmpt) the first Co(II) complexes with these ligands, i.e., [Co(Hmps)(H2O)X2] (X = Cl (1), Br (2)), [Co(Hmpt)2][CoCl4]∙2H2О (3) and [Co(Hmpt)2]Br2∙Me2CO (4) were obtained. Complexes 1 and 2 represent the first examples of metal complexes of Hmps. All the obtained compounds were characterized by elemental analysis, conductometry, magnetic measurements, and IR spectra, and for complexes 2–4, single crystal X-ray diffraction analysis was also performed. The effective magnetic moments were close to the upper limit (5 μB) for complexes 1 and 2, and close to the lower limit (4.4 μB) for complexes 3 and 4, and as such are characteristic for high-spin Co(II) complexes. Structural analysis showed that both ligands coordinate in a neutral form in a tridentate manner, via the ester oxygen, imine nitrogen and the oxygen atom of the ureido (Hmps), or the sulfur atom of the thioureido group (Hmpt). The central metal atoms are situated in a deformed octahedral coordination environment. Complex 2 has cis-Br configuration, while complexes 3 and 4 have mer-configuration

    Overview of carotenoids distribution among wild plant species of the Balkan Peninsula

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    The Balkan Peninsula is characterized by a great diversity of flora and vegetation. Moreover, it is native to a large number of wild plant species containing carotenoids, biologically active compounds, beneficial for human health. Carotenoid pigments exhibit a great antioxidant and anti-inflammatory effect, in addition to beneficial impact on eye health, heart, blood vessels, cognitive function and antiaging. Nevertheless, their role has been scientifically proven in prevention and treatment of cancer. The aim of the research was to form a database on carotenoid plants of Serbia and the Balkans that is set up electronically for easy access, management and updating. The research included the analysis and organization of information on collected plants, as well as literature data related to the traditional use and storage of plants and plant parts and products rich in carotenoids in fresh, dried or canned state. Sixty wild plants from more than ten plant families were registered to contain these antioxidant pigments. Among them three endemic species namely Lilium bosniacum (Beck) Fritsch (lily native to Bosnia and Herzegovina), Ramonda nathaliae Pančić & Petrović and R. serbica Pančić were inscribed, of which the last two are Tertiary relicts. The type and level of carotenoids varied depending on the plant species and organs including leaves, petals, immature and ripe fruits, pulp, seeds, etc. According to database, fruits were the richest source of these pigments. Reported carotenoid content, included both xanthophylls and carotenes, whereas lutein and β-carotene were predominantly major compounds in berries and flowers respectively. Total carotenoid content, determined by HPLC method, was the highest in fresh berries of Rubus fruticosus L. (440 μg/100g
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