Sürdürülebilir Kalkınma Amaçları

Yazarlar

  • BildiriYalnız künye2014
    Inverse Neumann problem for an equation of elliptic type

    Ashyralyyev, Charyyar; Ashyralyev, A; Malkowsky, E

    Inverse problem for an elliptic differential equation with Neumann conditions is considered. Stability and coercive stability estimates for the solution of inverse problem with the overdetermination are obtained. The first and second order of accuracy difference schemes are presented. Stability and coercive stability inequalities for these difference schemes are given. In application, inverse problem for the multidimensional elliptic equation is studied. The first and second order of accuracy difference schemes for the multidimensional inverse problem are presented. Well-posedness of both difference problems are established. The results are supported by a numerical example for the two-dimensional elliptic equation.

  • MakaleYalnız künye2014
    Pushover and nonlinear time history analysis evaluation of a RC building collapsed during the Van (Turkey) earthquake on October 23, 2011

    Çavdar, Özlem; Bayraktar, Alemdar

    The nonlinear seismic behavior of a collapsed reinforced concrete (RC) residential building in the city of Van in Turkey is investigated by the static pushover and nonlinear time history analyses. The selected RC structure was designed according to the 1975 version of Turkish Earthquake Code (TEC-1975). The building had experienced heavy damage, and it was demolished in the Van earthquake on October 23, 2011. The 2007 version of Turkish Earthquake Code (TEC-2007) is considered for the assessing seismic performance evaluation of the selected RC building. The RC structure presents collapse performance level under the earthquake loads. Besides, the analytical solutions show that different performance levels for the sections are obtained from the pushover and nonlinear time history methods.

  • MakaleYalnız künye2014
    Improvement of Coercivity and Curie Temperature of Sintered Nd-Fe-B Permanent Magnets by Addition of Cu and Ni

    Başoğlu, M.; Yanmaz, E.

    Sintered Nd-Fe-B magnets are some of the strongest magnetic materials showing magnetic properties. Blending addition is frequently performed in order to improve the magnetic properties of these materials. In this work, high-melting point Ni and low-melting point Cu were added to Nd15Fe77B8 ingot by blending. As a result of structural analysis, it was observed that 0.2 wt% Cu + Ni addition improved the structure of the material; on the other hand, excessive addition resulted in porosity. It was also observed that 0.2 wt% addition improved the magnetic properties, and Curie temperature increased with increasing addition ratio.

  • MakaleYalnız künye2014
    The effects of chemical attacks on physical and mechanical properties of concrete produced under cold weather conditions

    Çullu, Mustafa; Arslan, Metin

    This study investigates the effects of corrosive conditions on the physical and mechanical properties of concrete produced in cold weather. 30% calcium nitrate and 5% hydroxyethylaminemixture (HEA) were used as additives in antifreeze. Within 15 min of placing the prepared concrete samples in molds, the samples were put in a deep freezer. They were exposed to frost at 0 C, -5 C, -10 C, -15 C and -20 C degrees in the deep freezer over two days. The samples were taken out of the freezer and removed from the forms one day later. They were cured in water at room temperature until the 28th day. The samples were then exposed to sulfuric acid of 5% concentration (H2SO4), magnesium sulfate of 7500 mg/L concentration (MgSO4), sodium sulfate of 5% concentration (NaCl), and corrosive cure and water-curing until the 120th day. At the end of the curing period, the permeable pore space volume, water absorption ratio, unit volume weight, capillarity ratio, impermeability, compressive strength, static modulus of elasticity, Poisson's ratio and tensile strength values of the concrete samples were determined. The results showed that the physical and mechanical properties of the concrete were negatively affected by the corrosive conditions.

  • MakaleAçık Erişim2014
    Trace/heavy metal accumulation in soil and in the shoots of acacia tree, Gümüşhane-Turkey

    Vural, Alaaddin

    In this study, heavy metal/trace element accumulation was investigated in soils along the road passing through Gümüshane city center and shoots of 1-2 years of acacia trees (Robinia pseudoacacia L.) grown in these soils. Heavy metal contents in soils and plants were analyzed by Enrichment Factor (EF), Geo-accumulation index (Igeo) parameters, and by Bio Accumulation Factor (BAF), respectively. According to geo-accumulation index (Igeo) data, it is seen that the soil was unpolluted in terms of Cr, Co, Cu, Rb, Sr; unpolluted to moderately polluted in terms of V, Ni and Zn; moderate to excessively polluted in terms of As, and moderate to excessively polluted in terms of Pb. According to EF parameters, on the other hand, it is observed that the soil was non to slightly enriched in terms of Cr, Co, Sr and Ba; non to moderately enriched in terms of Ni and Cu; slightly to significantly enriched in terms of Zn; significant to very highly enriched in terms of As and slightly to over excessively enriched in terms of Pb. Although trace/heavy metal contents of acacia shoots were usually within normal values for acacia, it was determined that Cu, Fe, Mo, Ni, Sr and Zn concentrations were within and/or above upper limits of normal values in certain sampling points.

    • SDG 15 · Karasal Yaşam
  • MakaleYalnız künye2014
    Characterization of novel VIM carbapenemase, VIM-38, and first detection of GES-5 carbapenem-hydrolyzing β-lactamases in Pseudomonas aeruginosa in Turkey

    Iraz, Meryem; Duzgun, Azer Ozad; Cicek, Aysegul Copur; Bonnin, Remy A.; Ceylan, Aysenur; Saral, Aysegul; Nordmann, Patrice; Sandalli, Cemal

    Pseudomonas aeruginosa isolates were collected form a Turkish hospital. Antimicrobial susceptibility was performed using the Vitek 2 Compact system, and 24 isolates were categorized as multidrug resistant (n = 18), extensively-drug resistant (n = 5), or pan-drug resistant (n = I). PCR and DNA sequence analysis revealed that 1 strain possessed the bla(GES-5) and another carried a novel bla(VIM) variant, named VIM-38. This new gene exhibited 1 amino acid substitution (Ala265Val) in comparison to its closest variant, VIM-5. Both VIM encoding genes were clones and demonstrated similar susceptibility profile when expressed in identical background. The presence of VIM-38 increases the diversity of carbapenemases in Turkey. (C) 2014 Elsevier Inc. All rights reserved.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
  • MakaleAçık Erişim2014
    Protective effects of growth hormone on bacterial translocation and intestinal damage in rats with partial intestinal obstruction

    Kaymakci, A.; Guven, S.; Ciftci, I; Akillioglu, I; Aktan, M.; Eker, H. H.; Sutcu, A.; Abasiyanik, A.

    Objective: One of the reasons of bacterial translocation (BT) is the complete or partial intestinal obstructions (PIO) of the gastrointestinal system. In this study, we aimed to investigate the effects of recombinant human Growth Hormone (rhGH) on BT in rats with partial intestinal obstruction (PIO). Material and methods: The rats were randomly divided into the 4 groups: Group I: Sham-operated (SO) (n = 12), Group II control PIO (n = 12), Group III: PIO with rhGH treatment for 5 days (n = 12), Group IV: PIO with rhGH treatment 5 days before PIO and 5 days after PIO (a total of 10 days) (n = 12). In the groups III and IV, the effects of 5 and 10 days administered rhGH were examined. Results: The level of serum and of intestinal fluid IgA was significantly higher in the Group IV compared to the Group I, Group II and Group III. In the Group IV, the number of small intestinal goblet and colonic goblet cells, and the lengths of intestinal mucosal villi and crypt depths were statistically significantly higher than in Groups II and III. The rate of bacterial translocation was higher in the Group II: 100 % in MLNs, 41.6 % in blood culture and 50.8 % in the liver cultures, it was significantly higher compared to the other groups (p < 0.01). Conclusions: The study results demonstrated that administration of rhGH to the rats with PIO for at least 10 days decreased bacterial translocation (Fig. 3, Ref. 25). Text in PDF www.elis.sk.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
  • MakaleAçık Erişim2014
    Molecular Epidemiology, Antimicrobial Resistance and Characterization of Extended-Spectrum Beta-Lactamases of Salmonella enterica Serotype Paratyphi B Clinical Isolates

    Bayramoglu, Gulcin; Özgümüs, Osman Birol; Kolayli, Fetiye; Kamburoglu, Ahu; Besli, Yesim; Dinç, Ugur; Tosun, Ilknur; Aydin, Faruk

    Although Salmonella enterica serotype Paratyphi B is the less frequently isolated serotype worldwide and in Turkey, it is the most common serotype in our hospital, with a marked increase in 2007. The purpose of this study was to investigate the antibiotic susceptibility and the extended spectrum beta-lactamase (ESBL) profile, and molecular epidemiology of S. Paratyphi B isolates detected in our hospital microbiology laboratory. Seventy isolates identified as S. Paratyphi B from 109 Salmonella isolates obtained from clinical specimens from different patients between October 2005 and December 2012, were included in the study. In addition to conventional methods, isolates were identified using the Phoenix automated microbiology system (Becton Dickinson, USA). Serotyping of the isolates was performed on the basis of slide agglutination and the Kauffmann-White scheme. The antibiotic susceptibility of the isolates was determined using the BD Phoenix (TM) automated system and disk diffusion test. ESBL enzymes were investigated using the combined disk test, isoelectric focusing, polymerase chain reaction (PCR) and sequence analysis. The molecular epidemiology of the 51 isolates obtained between October 2005 and August 2008 was examined with pulsed-field gel electrophoresis (PFGE) using the Xbal enzyme. S. Paratyphi B isolates were obtained from 70 specimens (46 blood, 16 fecal, 4 bone marrow, 2 urine and 2 wound) each from different patients. Resistance to nalidixic acid was determined in 18.6%, resistance to ampicillin, cefotaxime and cefepime in 2.9% and to ceftazidime and co-trimoxazole in 1.4% of the isolates. ESBL production was detected only in two isolates; in one TEM-1 was accompanied by CTX-M-15 and in the other isolate CTX-M-3 was found. Forty-six of the 51 isolates (90%) were found to be genetically related by PFGE and were placed in cluster A. The distribution of the isolates in cluster A revealed six subtypes as A1 (n= 7), A2 (n= 11), A3 (n= 7), A4 (n= 18), AS (n= 2) and A6 (n= 1). Three different patterns not related to the cluster A were determined in the remaining five isolates (two were B, one of each was C, D and E). In conclusion, although the rate of antibiotic resistance was low in the S. Paratyphi B isolates in our hospital, rare types of ESBLs such as CTX-M-3 and CTX-M-15 were detected in Salmonellae. As far as the current literature is considered, this is the first report in Turkey of bla(CTX-M-15) in Salmonella spp. and bla(CTX-M-3) genes in S. Paratyphi B. The results may indicate a possible future threat to the treatment of Salmonella infections. Since most of the isolates were genetically related, this might suggest an epidemic in our region.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
  • MakaleAçık Erişim2014
    Poly(ε-caprolactone) Composite Scaffolds Loaded with Gentamicin-Containing β-Tricalcium Phosphate/Gelatin Microspheres for Bone Tissue Engineering Applications

    Sezer, Umran Aydemir; Arslantunali, Damla; Aksoy, Eda Ayse; Hasirci, Vasif; Hasirci, Nesrin

    In this study, novel poly(epsilon-caprolactone) (PCL) composite scaffolds were prepared for bone tissue engineering applications, where gentamicin-loaded -tricalcium phosphate (-TCP)/gelatin microspheres were added to PCL. The effects of the amount of -TCP/gelatin microspheres added to the PCL scaffold on various properties, such as the gentamicin release rate, biodegradability, morphology, mechanical strength, and pore size distribution, were investigated. A higher amount of filler caused a reduction in the mechanical properties and an increase in the pore size and led to a faster release of gentamicin. Human osteosarcoma cells (Saos-2) were seeded on the prepared composite scaffolds, and the viability of cells having alkaline phosphatase (ALP) activity was observed for all of the scaffolds after 3 weeks of incubation. Cell proliferation and differentiation enhanced the mechanical strength of the scaffolds. Promising results were obtained for the development of bone cells on the prepared biocompatible, biodegradable, and antimicrobial composite scaffolds. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40110.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
  • MakaleAçık Erişim2014
    Oxidant-Antioxidant Balance during On-Pump Coronary Artery Bypass Grafting

    Mentese, Umit; Dogan, Orhan Veli; Turan, Ibrahim; Usta, Sefer; Dogan, Emre; Mentese, Seda Oztas; Demir, Selim; Ozer, Tanil; Aykan, Ahmet Cagri; Alver, Ahmet

    Backround. The aim of this study was to evaluate the changes in perioperative oxidant-antioxidant balance in ONCABG. Methods. Twenty-three patients were included in this study. Serum total oxidant status (TOS), total antioxidant status (TAS), and oxidative stress index (OSI) values were assessed preoperatively, at 20 minutes after aortic clamping and at 30 minutes, 6 hours, and 48 hours after declamping (reperfusion). The patients were divided into 2 groups according to the median aortic cross clamping (XC) time: group 1 (XC time < 42 minutes) and group 2 (XC time >= 42 minutes). Results. TOS and OSI values of whole patients at 30 minutes after reperfusion were higher than preoperative values (P = 0.045, P = 0.015), while perioperative TAS levels of the patients were similar to the preoperative levels (P = 0.173). XC time was correlated with TOS levels at 30 minutes after reperfusion (P = 0.43, P = 0.041). In group 2, TOS and OSI values at 30 minutes after reperfusion were higher than preoperative values (P = 0.023, P = 0.048), whereas a significant difference was not found in group 1 (P = 0.601, P = 0.327). Conclusions. Oxidative imbalance and increase in TOS at reperfusion in ONCABG may be associated with XC time.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
  • MakaleAçık Erişim2014
    Oxidation of cyanobenzocycloheptatrienes: Synthesis, photooxygenation reaction and carbonic anhydrase isoenzymes inhibition properties of some new benzotropone derivatives

    Güney, Murat; Coskun, Ahmet; Topal, Fevzi; Dastan, Arif; Gülçin, Ilhami; Supuran, Claudiu T.

    The oxidation of some cyanocycloheptatrienes with CrO3 and pyridine was investigated and a few new nitrile functionalised benzotropone derivatives were obtained. Photooxygenation reaction of these products was also studied. The structures of the formed products were determined on the basis of NMR spectroscopy and the formation mechanism of unusual products was discussed. Human carbonic anhydrase isoenzymes I, and II (hCA I and hCA II) inhibition properties of nitrile functionalized new benzotropone derivatives were also studied. Both CA isozymes were inhibited in the low micromolar range by these nitrile functionalized benzotropone analogues. The newly synthesized benzotropone derivatives showed inhibition constants in the sub-micromolar range (2.51-4.06 mu M). The best hCA I inhibition was observed in 5H-benzocycloheptene-7-carbonitrile (K-1: 2.88 +/- 0.86 mu M). On the other hand, 5-oxo-5H-benzocycloheptatriene-7-carbonitrile showed the powerful inhibitory effect against hCA II (K-i: 2.51 +/- 0.34 mu M). (C) 2014 Elsevier Ltd. All rights reserved.

  • MakaleYalnız künye2014
    The Eastern Black Sea-type volcanogenic massive sulfide deposits: Geochemistry, zircon U-Pb geochronology and an overview of the geodynamics of ore genesis

    Eyuboglu, Yener; Santosh, M.; Yi, Keewook; Tuysuz, Necati; Korkmaz, Sadettin; Akaryali, Enver; Dudas, Francis O.; Bektas, Osman

    The Meso-Cenozoic geodynamic evolution of the eastern Pontides orogenic belt provides a key to evaluate the volcanogenic massive sulfide (VMS) deposits associated with convergent margin tectonics in a Cordilleran-type orogenic belt. Here we present new geological, geochemical and zircon U-Pb geochronological data, and attempt to characterize the metallogeny through a comprehensive overview of the important VMS mineralizations in the belt. The VMS deposits in the northern part of the eastern Pontides orogenic belt occur in two different stratigraphic horizons consisting mainly of felsic volcanic rocks within the late Cretaceous sequence. SHRIMP zircon U-Pb analyses from ore-bearing dacites yield weighted mean Pb-206/U-238 ages ranging between 91.1 +/- 1.3 and 82.6 +/- 1 Ma. The felsic rocks of first and second horizons reveal geochemical characteristics of subduction-related calc-alkaline and shoshonitic magmas, respectively, in continental arcs and represent the immature and mature stages of a late Cretaceous magmatic arc. The nature of the late Cretaceous magmatism in the northern part of the eastern Pontides orogenic belt and the various lithological associations including volcaniclastics, mudstones and sedimentary facies indicate a rift-related environment where dacitic volcanism was predominant. The eastern Pontides VMS deposits are located within the caldera-like depressions and are closely associated with dome-like structures of felsic magmas, with their distribution controlled by fracture systems. Based on a detailed analyses of the geological, geophysical and geodynamic information, we propose that the VMS deposits were generated either in intra arc or near arc region of the eastern Pontides orogenic belt during the southward subduction of the Tethys oceanic lithosphere. (C) 2013 Elsevier B.V. All rights reserved.