84 research outputs found

    Dynamic / Thermochemical Method: A Novel Approach in The Synthesis of B4C Powder

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    The synthesis of high quality B4C powders with high purity, uniaxial shape and homogeneous size distribution, has been hard to obtain. Current production methods take place at temperatures above 1800 C, yielding high free carbon and large particle size. In this study, using a novel and patented approach, a reaction temperature of 1500 C for 1 h was sufficient to synthesize fine B4C powders from boron oxide (B2O3) and carbon black (C). This technique is based on the dynamic/thermochemical method (DTM), in which B2O3 and C powders are granulated before being charged into an atmosphere-controlled rotary type furnace. The granulation process and parameters of raw materials were the key to obtain high purity B4C powders, with equiaxed-grains and homogenous distribution with an average size of 10 ÎŒm

    Effect of Zofenopril on regeneration of sciatic nerve crush injury in a rat model

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    <p>Abstract</p> <p>Background</p> <p>Zofenopril is an antioxidant agent which has been shown to have beneficial effects in hypertension and heart failure. The aim of this study was to test the effects of Zofenopril on nerve regeneration and scarring in a rat model of peripheral nerve crush injury.</p> <p>Methods</p> <p>Twenty-one adult Sprague-Dawley rats underwent a surgical procedure involving right sciatic nerve crush injury. 15 mg/kg Zofenopril was administered orally to seven rats in group Z for seven days. Seven rats in group S received saline orally for seven days. Seven rats in the control group C received no drug after crush injury. Fourteenth and 42nd days after injury, functional and electromyography assessments of nerves were performed. Functional recovery was analyzed using a walking track assessment, and quantified using the sciatic functional index (SFI). After these evaluations, all rats were sacrificed and microscopic evaluations were performed.</p> <p>Results</p> <p>The Sciatic functional Index (SFI) in group Z on 14<sup>th </sup>day is different significantly from group S and group C (p = 0.037). But on 42<sup>nd </sup>day there was no difference between groups (p = 0.278). The statistical analyses of electromyelographic (EMG) studies showed that the latency in group Z is significantly different from group S (p = 0.006) and group C (p = 0.045). But on 42<sup>nd </sup>day there was no difference between groups like SFI (p = 0.147). The amplitude was evaluated better in group Z than others (p < 0.05). In microscopic evaluation, we observed the highest number of nerve regeneration in the group Z and the lowest in the group C. But it was not significant statistically.</p> <p>Conclusion</p> <p>Our results demonstrate that Zofenopril promotes the regeneration of peripheral nerve injuries in rat models.</p

    Evaluation of the analytical performances of Cobas 6500 and Sysmex UN series automated urinalysis systems with manual microscopic particle counting

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    Introduction: Automated urinalysis systems are valuable tools in clinical laboratories, especially those with a high work load. The objective of this study was to compare the analytical performance of Sysmex UN series urine analyser, which may become a new one in our laboratory, with the Cobas 6500 automated urine analyser, which is used in our laboratory for a long time. For comparisons, manual microscopical examination was accepted as reference method. Materials and methods: A total of 470 urine samples were tested in the two automated urinalysis systems, and urine sediment testing with manual microscopy was applied to a 100 pathological samples of the total 470. The diagnostic performance of the two automated urine analysers was compared with each other and manual microscopy. Results: Differences were determined between automated and manual microscopy in some pathological samples. The resultant regression equations were as follows. Comparison of Cobas U701 with Sysmex UF-5000: y = - 0.57 (- 0.85 to - 0.29) + 0.95 (0.92 to 0.99) x for RBC, and y = - 0.11 (- 0.54 to 0.29) + 0.89 (0.84 to 0.98) x for WBC; comparison of Cobas U701 with manual microscopy: y = - 0.45 (- 0.85 to 0.21) + 1.00 (0.92 to 1.07) x for WBC; and comparison of Sysmex UF-5000 with manual microscopy: y = - 0.74 (- 1.09 to - 0.57) + 0.87 (0.85 to 0.91) x for WBC. Conclusions: We can conclude that the new Sysmex UN series urine analyser can be safely used in our laboratory. Although the results showed good to moderate concordance, the microscopy results of the automated platforms should be confirmed by manual microscopy, particularly in pathological samples

    The effects of age and individual size on metal levels of Serranus cabrilla (Linnaeus, 1758) from the YeƟilovacık Bay (Northeasthern Mediterranean, Turkey)

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    In this study, the relationships were determined between the macro (Na, Mg, P, K, Ca), potential toxic metal, As, and trace element, Zn, levels of the muscle tissue and fish size (length and weight) in Serranus cabrilla (Linnaeus, 1758) caught via bottom trawl boat from the YeƟilovacık Bay (Northeastern Mediterranean, Turkey). The potential toxic metal, macro and trace element levels of the muscle tissue of S. cabrilla were determined. Besides, the relationships between fish size and metal levels were investigated. For this study, S. cabrilla individuals of 0-1, 1-2 and 2-3 age groups were used. Min-Max total length of the age groups was determined as 10.5-11.8, 13.0-15.5 and 15.8-16.5 cm; Min-Max weights were 15.34-23.66, 30.41-43.82 and 41.89-58.18 g respectively. There was no statistical difference between the age groups according to the macro and trace element levels of muscle tissue. The Arsenic levels of the muscle tissue were high and in general displayed variation with age. The present study firstly reported the relationship between mineral-metal levels and individual size-age of S. cabrilla

    Changes in Dynamics upon Oligomerization Regulate Substrate Binding and Allostery in Amino Acid Kinase Family Members

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    Oligomerization is a functional requirement for many proteins. The interfacial interactions and the overall packing geometry of the individual monomers are viewed as important determinants of the thermodynamic stability and allosteric regulation of oligomers. The present study focuses on the role of the interfacial interactions and overall contact topology in the dynamic features acquired in the oligomeric state. To this aim, the collective dynamics of enzymes belonging to the amino acid kinase family both in dimeric and hexameric forms are examined by means of an elastic network model, and the softest collective motions (i.e., lowest frequency or global modes of motions) favored by the overall architecture are analyzed. Notably, the lowest-frequency modes accessible to the individual subunits in the absence of multimerization are conserved to a large extent in the oligomer, suggesting that the oligomer takes advantage of the intrinsic dynamics of the individual monomers. At the same time, oligomerization stiffens the interfacial regions of the monomers and confers new cooperative modes that exploit the rigid-body translational and rotational degrees of freedom of the intact monomers. The present study sheds light on the mechanism of cooperative inhibition of hexameric N-acetyl-L-glutamate kinase by arginine and on the allosteric regulation of UMP kinases. It also highlights the significance of the particular quaternary design in selectively determining the oligomer dynamics congruent with required ligand-binding and allosteric activities

    GrassPlot - a database of multi-scale plant diversity in Palaearctic grasslands

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    GrassPlot is a collaborative vegetation-plot database organised by the Eurasian Dry Grassland Group (EDGG) and listed in the Global Index of Vegetation-Plot Databases (GIVD ID EU-00-003). GrassPlot collects plot records (releves) from grasslands and other open habitats of the Palaearctic biogeographic realm. It focuses on precisely delimited plots of eight standard grain sizes (0.0001; 0.001;... 1,000 m(2)) and on nested-plot series with at least four different grain sizes. The usage of GrassPlot is regulated through Bylaws that intend to balance the interests of data contributors and data users. The current version (v. 1.00) contains data for approximately 170,000 plots of different sizes and 2,800 nested-plot series. The key components are richness data and metadata. However, most included datasets also encompass compositional data. About 14,000 plots have near-complete records of terricolous bryophytes and lichens in addition to vascular plants. At present, GrassPlot contains data from 36 countries throughout the Palaearctic, spread across elevational gradients and major grassland types. GrassPlot with its multi-scale and multi-taxon focus complements the larger international vegetationplot databases, such as the European Vegetation Archive (EVA) and the global database " sPlot". Its main aim is to facilitate studies on the scale-and taxon-dependency of biodiversity patterns and drivers along macroecological gradients. GrassPlot is a dynamic database and will expand through new data collection coordinated by the elected Governing Board. We invite researchers with suitable data to join GrassPlot. Researchers with project ideas addressable with GrassPlot data are welcome to submit proposals to the Governing Board

    Intrascrotal Extratesticular Angiolipoma in a 3-Year-Old Child: A Report of an Uncommon Case

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    Angiolipoma is an uncommon benign lipomatous neoplasm which occurs more frequently on the arms and trunk in teenagers and young adults. It is rare in children and in patients older than 50 years. Angiolipomas often present as tender or rarely non-tender subcutaneous nodules with overlying skin discoloration. A case of intrascrotal angiolipoma was reported in this article. A three-year-old child was operated due to right scrotal mass (9 x 5 cm). The pathologic examination revealed angiolipoma. An angiolipoma may be present as a scrotal mass and this pathological entity should be considered in the differential diagnosis of scrotal masses in childhood. To the best of our knowledge, this case is the first report of intrascrotal angiolipoma in the English literature. The case was been reported in view of its rarity, atypical presentation and atypical clinical picture
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