36 research outputs found

    Synthesis of chalcone-containing zinc and cobalt metallophthalocyanines; investigation of their photochemical, DPPH radical scavenging and metal chelating characters

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    In this study, two new phthalocyanines (M = Zn and Co) were synthesized using the (E)-4-(4-(3-(4- (benzyloxy)phenyl)acryloyl)phenoxy)phthalonitrile (3) as ligand prepared from the chemical reaction of 4- nitrophthalonitrile with (E)-3-(4-(benzyloxy)phenyl)-1-(4-hydroxyphenyl)prop-2-en-1-one (2). All compounds were characterized using by 1H-NMR, 13C-NMR, UV–Vis, FT-IR, and MALDI-TOF mass spectra. Singlet oxygen quantum yields of the synthesized compounds, aggregates in different solutions, metal chelating and 2,2- Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging properties were reported

    The examination of protective effects of gallic acid against damage of oxidative stress during induced-experimental renal ischemia-reperfusion in experiment

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    Aim: In this study, probable effects of gallic acid were investigated in experimentally induced renal I/R injury in rats. Material and methods: For this purpose, each group consisted of 7 Sprague dawley male albino rats. Groups were defined as follows; Group I: control group; Group II: I/R group; Group III, IV and V: I/R+Gallic acid (50, 100 and 200 mg.kg(-1) respectively-i.p.). Left kidney was removed by nephrectomy except for Group I. I/R was induced in the other kidney. Gallic acid was given 15 mins before ischemia induction. SOD, CAT and Gpx activities were determined by electrophoresis. MDA, MPO levels were determined spectrophotometrically. Histopathological investigations were also performed in kidney tissues. BUN and Creatinine levels in serum were determined. Results: BUN, Creatinine and MDA levels were statistically significant but MPO level was not statistically significantly increased in Group II. For SOD, CAT, Gpx activities in Group II, an increase was determined with respect to Group I. Histopathological investigations revealed widespread hyperemia in glomerulus, expansion of the structure between tubules and cell disruptions in Group II. In Group V (200 mg.kg-1 gallic acid), in terms of biochemical parameters, in spite of the significant decrease in BUN, Creatinine and MDA levels; a decrease was determined in SOD, CAT and Gpx isoenzyme activities. Group V showed histologically that I/R injury had been prevented to a greater extent and appearances were close to the control. Conclusion: As a result, in terms of our study, evaluations regarding kidney functions and histopathology have shown that gallic acid has protective effects in renal I/R injury (Tab. 2, Fig. 5, Ref. 36). Text in PDF www.elis.sk

    Gözenekli si ve ge nanoyapılarının ileri teknoloji güneş gözelerine uygulanması

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    TÜBİTAK MFAG01.04.2014Uluslararası ikili işbirliği projesi olan bu çalışmada amaca uygun olarak gözenekli silisyum ve germanyum nanoyapılar silisyum oksit matris içerisinde büyütülmüş ve optoleektronik aygıt üretiminde kullanılmıştır. Söz konusu yapıları elde edebilmek için silisyum ve germanyum-zengin silisyum oksit ince filmler fiziksel yolla buhar depolama yöntemlerinden yararlanarak üretilmiş ve kristal oluşumunu sağlamak için de yüksek sıcaklık fırını, hızlı termal tavlama ve lazer tavlama yöntemleri gibi farklı teknikler kullanılarak tavlanmıştır. Bu sayede farklı boyutlarda nanokristaller oluşturulmuş ve elde edilen yapıların optik band aralığının değişken olması sağlanmıştır. Böylece bu proje ile güneş spektrumundan daha fazla ve daha verimli yararlanmak amaçlı optik band aralığı ayarlanabilir malzemeler üretmiş bulunmaktayız. Öte yandan ürtetilen filmler, aygıt üretiminde gerekli olan elektrik akım geçişini sağlamk açısından da istenen şartları sağlamıştır. Böylece proejnin en önemli hedefi olan kuantum etkileri koruyarak, iletken tabakaların elde edilmesi hedefine ulaşılmıştır. Daha sonra bu yapılar, heteroeklem türü p-n eklemlei üretilmiş ve bu eklemlerin elektro- optik özellikleri belirlenmiştir. Si nanoyapılı örnekler güneş gözesi özellikleri sergilerken, Ge nanoyapılı örnekler de daha çok fotoalgılama yeteneği öne çıkmıştır. Bu çalışma ile ilk defa üretilen ve umut verici sonuçlar veren bu tür aygıtların daha da geliştirilmesi için yeni çalışmaların yürütülmesi gerekmektedir. Proje önerisi 24 ay gibi nispeten kısa bir sürede çok sayıda iş yapmayı hedefleyen bir proje olarak sunulmuştur. Uluslararası bir organizasonu da içeren zorlu bir programı olanproje hedeflerine büyük ölçüde ulaşmıştır. Çok sayıda deney ve çalışma yürütülmüştür. Bu çalışmaların bir özeti bu sonuç raporunda sunulmuştur.In this international bilateral cooperation project, silicon and germanium nanostructures embedded in silicon oxide matrix have been produced, optimized and used in some optoelectronic devices. In order to obtained these new material types, Si and Ge materials were co-sputtered together with SiO2 on a substrate, and annealed using conventional and rapid thermal annealing systems as well as laser annealing systems. In this way, nanostructures embedded in a dielectric matrix have been obtained. Such nanostructures are expected to yield materials with tunable band gap which depends on this size of the nanoparticles. A device having different band gap is expected to provide a more efficient light harvesting from the solar radiation. On the other hand, when these nanostructure are somehow interconnected, electrical transport becomes more feasible, which is contrary to the case where isolated nanocrystals are used. We have reached this goal through a series of experiments during this project. We have shown that both electrical transport and quantum confinement can be obtained in the same material system. After having optimized the material system, we have applied them to heterojunction type p-n diodes for demenstration. Devices with Si nanostructure have exhibited solar cell properties with weak efficiency, while those with Ge nanostructures have shown photodiode features only. These type of device have been produced for he first time in this project. They have shown some promising features. However, they need to be studied and optimized for an actual appliction. This porject was submitted as an ambitious study to be performed in a relatively short time. In addition to its scientific and tecjhnical program, it also included international oragnization tasks, which sometimes slows down the prject execution In spite of laa these difficulties, and the heavy content, we have achived most of goals through extensive experiments and studies. Below, we present a summary of our project acitivities and the results obtained from these studies

    Bloodstream Infections by Extended-spectrum β-lactamase-producing Klebsiella Species in Children

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    Infections caused by resistant Gram-negative bacteria are a serious public health problem, with Klebsiella spp. being the most common cause and increasing over the years. There is a striking increase in antibiotic resistance worldwide. The aim of this study was to retrospectively evaluate the characteristics and treatment of bloodstream infections (BSIs) caused by Klebsiella spp. and to identify possible risk factors for extended-spectrum β-lactamase (ESBL) resistance in our hospital between August 2019 and March 2023. Of 250 Klebsiella isolates, 112 (44.8%) were ESBL producers and 138 (55.2%) were ESBL nonproducers. Catheter-related BSIs (CRBSIs) accounted for 49.6% of infections and were more common in the ESBL nonproducer group. Most of the Klebsiella spp. were K. pneumoniae (233/250). Most of the infections were healthcare-associated infections (85.6%). Most patients had an underlying disease, the most common underlying disease in the ESBL-producing group was neurometabolic disease (26.8%), whereas in the ESBL-non-producing group it was malignancy (35.5%). The median age of the ESBL-producing group was 14 months and was younger (p=0.01). Previous antibiotic use in the last 30 days, especially aminoglycosides (p<0.006), β-lactam-β-lactamase inhibitor combinations (p<0.001) and cephalosporins (p<0.001), increased ESBL-resistant infection. Use of β-lactam-β-lactamase inhibitor combinations in the last 30 days increased the risk of ESBL resistance by approximately 7.4 times, and cephalosporins increased the risk by 5 times. In the ESBL-producing group, the median duration of treatment was longer at 14 days (p=0.01), and carbapenems were most commonly used (p<0.001). Thrombocytopenia (p=0.003), elevated C-reactive protein (p<0.001), CRBSI (p=0.009), presence of central venous catheter (p=0.03), urinary catheter (p<0.001), mechanical ventilation (p<0.001), intensive care admission (p=0.005), previous use of carbapenems, aminoglycosides, fluoroquinolones in the last 30 days (p=0.003, p=0.001, p=0.006, respectively) and colistin treatment (p<0.001) increased the risk of mortality. The 28-day mortality rate was 11.6%. Appropriate use of narrow-spectrum antibiotics and reduction of invasive procedures is important in reducing ESBL resistance and BSI-related mortality

    The views of the academicians related to academic career levels and promotion criteria

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    Bu çalışmada, üniversitelerde görev yapan akademisyenlerin akademikkariyer basamakları ve yükseltilme ölçütlerine ilişkin görüşleri ele alınmıştır. Bu amaçla on beş akademisyenle görüşme yapılmış ve çalışma sonucunda, akademisyenlerin kariyer sürecinin kişisel ve çevresel pek çokfaktör tarafından olumlu/olumsuz şekilde etkilendiği, akademisyenlerinbilimsel çalışma yaparken pek çok kaygı içinde olduğu, nitelikli akademisyenlerin özelliklerini değerlendirmek için kullanılacak performans değerlendirme ölçütlerinin niceliksel değil niteliksel bazda olması gerektiği anlaşılmıştırIn this study, the views of the university faculty members related to academic career process and academic promotion criteria have been discussed. For this reason, fifteen academicians were interviewed. As a result ofthe study, it has been understood that the career process of the facultymembers have been affected by many factors such as personal or environmental factors positively or negatively, faculty members have many anxiety during the scientific research and academic performance evaluationcriteria which will be used to evaluate the properties of qualified academics should be qualitative base instead of quantitativel

    Thermal comfort properties of simulated multilayered diaper structures in dry and wet conditions

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    The objective of this research is to study the thermal comfort of simulated multilayered diaper structures in dry and wet conditions. To that end, a back sheet, breathable films, a superabsorbent core, and top sheets were provided and diaper structures were generated. In order to reveal their possible effects on thermal comfort, five different types of breathable films and two different types of top sheet layers were selected. Relative water vapor permeability, water vapor resistance, thermal conductivity, thermal resistance, and thermal absorptivity characteristics were analyzed and the results were evaluated statistically using analysis of variance tests. The test results indicated that the breathable film type and the top sheet type used showed significant changes on the breathability and thermal comfort of the diaper structures in dry state. Nevertheless, no statistically significant effects were observed in wet state

    Ankara tavşanı ince bağırsağında paneth hücrelerinin morfolojisi, histokimyası ve ince yapısı üzerinde çalışmalar

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    Bu araştırma, Ankara tavşanı ince bağırsağındaki Paneth hücrelerinin morfolojisini, histokimyasal özelliklerini, yerleşim bölgelerini ve sayısal dağılımını ortaya koymak amacıyla yapıldı. Çalışmada materyal olarak özel yetiştiricilerden sağlanan 10 adet sağlıklı, erişkin Ankara tavşanının duodenum, jejunum ve ileumlarından alınan doku örnekleri kullanıldı. Lieberhkühn kriptlerinde gözlenen Paneth hücreleri, bazalinde çekirdeği ve apikalindeki asidofilik granülleriyle tanındı. Granüller, Mallory’nin üçlü boyama tekniği, Phloxine-tartrazine, Alcian blue-performik asit ve Mallory’nin fosfotungstik asit-hematoksilen uygulamasına pozitif reaksiyon, Periyodik asit-Schiff (PAS), Alcian blue (pH 2.5), PAS-Alcian blue pH 2.5 boyamalarına ise negatif reaksiyon verdi. Paneth hücrelerinin ince bağırsağın tüm uzunluğu boyunca homojen bir dağılım göstermediği, hücre yoğunluğunun duodenumdan ileuma doğru gidildikçe arttığı gözlendi. İnce bağırsağın üç bölgesi arasındaki farkın istatistiksel olarak önemli olduğu (p<0.01) saptandı. Elektron mikroskobik incelemelerde bazı Paneth hücrelerinin apikal sitoplazmasında elektron yoğun ve homojen granüller, bazılarında ise elektron yoğunlukları farklı olan homojen granüller görüldü

    İnekte ovarial mast hücreleri üzerine morfolojik çalışmalar

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    Özet: Bu araştırma, östrual ve luteal fazlarda inek ovaryumunun farklı bölgelerindeki mast hücrelerinin boyanma özelliklerini, ışık ve elektron mikroskobik görünümlerini ve sayısal dağılımlarını belirlemek amacıyla yapıldı. Çalışmada 7'şer adet östrual ve luteal fazlardaki inek ovaryumu materyal olarak kullanıldı. Ovaryumda korpus luteum çevresinden, graff follikül çevresinden ve medulladan olmak üzere üç bölgeden parça alındı. Her üç bölgeden alınan parafin kesitlerinde toluidin blue ile metakromazi gösteren, alcian blue / safranin O (Ab/SO) kombine boyamasında Ab(+) / SO(-) boyanma özelliği gösteren mast hücrelerine rastlandı. Elektron mikroskobik incelemelerde mast hücrelerinin homojen yoğun ve ince tanecikli olmak üzere iki tip granül içerdiği gözlendi. Ovaryumun her üç bölgesinde de östrual fazda, luteal faza göre mm2>deki ortalama mast hücresi sayısının arttığı görüldü (P < 0,001). Estrual dönemde graaff follikülü çevresinde mast hücresi sayısında belirgin artış olurken, corpus luteum çevresinde az sayıda mast hücresine rastlandı. Ovaryumun üç bölgesi karşılaştırıldığında her iki fazda da mast hücre yoğunluğunun medullada olduğu gözlendi.Abstract: This study was conducted on cows in the estrual and luteal phases of the cycle to determine the staining properties, light and electron microscopic appearance and numerical distribution of mast cells from various areas of the ovary. The material for the study comprised ovarian specimen taken from 14 cows, 7 in the luteal phase and 7 in the estrual phase of the sexual cycle. Specimens were taken from 3 different areas of the ovaries, including those surrounding the corpus luteum, the graafian follicle and the medulla. From all 3 areas, mast cells were demonstrated as metachromatic staining after treatment of paraffin-embedded sections with toluidine blue and as Ab(+)/SO(-) by the combined alcian blue/safranine O (Ab/SO) stain. In the electron microscopic studies, the mast cells were observed to have 2 types of granules, namely homogeneously dense granules and tiny particulate granules. All 3 regions of the ovary were observed to have higher average mast cell counts per mm2 during the estrual phase than during the luteal phase (P &lt; 0.001). In the estrual phase, while mast cell counts demonstrated a marked increase in the periphery of the graafian follicle, a low number of mast cells was determined in the periphery of the corpus luteum. In comparison, the medulla was demonstrated to have a much higher concentration of mast cells in the medulla than the other 2 regions of the ovarium

    Optimization of sodium extraction from soil by using a central composite design (CCD) and determination of soil sodium content by ion selective electrodes

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    Rapid determination of sodium (Na) ions in soil samples using ion selective electrodes (ISE) was investigated in this study. The compatibility of ISEs with soil extraction solution is a challenging subject as various effects such as pH, ionic strength and other interferences have to be considered as well as efficiency of the extraction solution. Because almost every type of sodium salt is soluble in water, and the pH of water is suitable for ISE studies, it was chosen as the soil extractant. Firstly, the extraction parameters were optimized by using a central composite design (CCD), secondly thirty agricultural soil samples were extracted with water and the extracts were measured by Na-ISE in a previously developed flow system. The results were compared with ion chromatography (IC) as the reference method, and the regression analysis between IC and ISE results yielded a high correlation (R² = 0.9408). It was concluded that, ion selective electrodes can be used with water as an extraction solution for rapid determination of sodium in soil samples
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