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Comparison of the effects of cross-validation methods on determining performances of classifiers used in diagnosing congestive heart failure

İşler, Yalçın | Narin, Ali | Özer, Mahmut

Article | 2015 | Measurement Science Review15 ( 4 ) , pp.196 - 201

Congestive heart failure (CHF) occurs when the heart is unable to provide sufficient pump action to maintain blood flow to meet the needs of the body. Early diagnosis is important since the mortality rate of the patients with CHF is very high. There are different validation methods to measure performances of classifier algorithms designed for this purpose. In this study, k-fold and leave-one-out cross-validation methods were tested for performance measures of five distinct classifiers in the diagnosis of the patients with CHF. Each algorithm was run 100 times and the average and the standard deviation of classifier performances were . . . recorded. As a result, it was observed that average performance was enhanced and the variability of performances was decreased when the number of data sections used in the cross-validation method was increased. © by Yalcin Isler 2015 Daha fazlası Daha az

Molybdenum tetracarbonyl complexes with linear chain polyether-containing Schiff base ligands and their reactivity in the polymerization of methyl methacrylate

Menteş, Ayger | Sarbay, Mithat | Hazer, Baki | Arslan, Hülya

Article | 2005 | Applied Organometallic Chemistry19 ( 1 ) , pp.76 - 80

Mo(CO)6 was reacted with the Schiff base ligand obtained by condensation reaction of 2-acetyl- or benzoylpyridine with poly(propylene glycol)bis(2-aminopropyl ether) to obtain polymeric, dinuclear metal tetracarbonyl compounds. The long-chain Schiff base complexes are highly soluble even in non-polar solvents such as petroleum ether, diethyl ether and n-hexane. These complexes, as free-radical initiators, afforded methyl methacrylate polymerization in chlorinated solvents. Copyright © 2004 John Wiley & Sons, Ltd.

Idiopathic scrotal calcinosis with polypoid appearance

Numanoğlu-Yurdakan, Gamze | Çolak, Sacide | Hoşnuter, Mubin | Gün, Banu D. | Bostan, Süheyla | Özdamar, Oğuz

Article | 2008 | Gazi Medical Journal19 ( 2 ) , pp.80 - 81

İdiopatik skrotal kalsinozis, skrotum derisinde çok sayıda sert nodüllerin varlığıyla karakterizedir. Nodüler kalsifikasyonlar tipik olarak yaşamın 2. dekatında görülür. Bu lezyonlar asemptomatik, yuvarlak sert papüller durumundadır. Olgu 53 yaşında skrotumda ağrısız, sert nodüller ile başvurdu. Lezyonların 23 yaşında iken görülmeye başladığı ve bazılarının zamanla ilerleyerek polipoid forma dönüştüğü öğrenildi. Hastanın öyküsünde travma veya cerrahi tedavi yoktu. Serum kalsiyum, fosfor, kalsitonin ve paratiroid hormon seviyeleri normal sınırlardaydı. Kistlerin histopatolojik incelemesinde epitelle döşeli olmayan keratin içeriklerin . . .in distrofik kalsifikasyonu görüldü. Bilgilerimize göre bu olgu literatürde bildirilen polipoid görünümlü ikinci skrotal kalsinozis olgusudur. Idiopathic scrotal calcinosis is characterized by the presence of multiple firm nodules of scrotal skin. The nodular calcifications are typically found in the second decade of life. The lesions are seen as asymptomatic, round, firm papules. A 53-year-old man was admitted with painless, firm nodules within the scrotum. The lesions had begun to appear at the age of 23 years and some of them had become polypoid progressively over time. There was no trauma or previous surgical treatment. The serum levels of calcium, phosphorus, calcitonin, and parathyroid hormone were within normal limits. The polypoid masses were surgically excised. Histological examination of the cysts revealed dystrophic calcification of their keratin contents but no epithelial lining. To the best of our knowledge, this is the second case of scrotal calcinosis with polypoid appearance in the literature Daha fazlası Daha az

Synthesis and characterization of stereoregular poly(N-ethylacrylamide) hydrogel by using Y(OTf)(3) Lewis acid

Biswas, Chandra Sekhar | Hazer, Baki

Article | 2015 | COLLOID AND POLYMER SCIENCE293 ( 1 ) , pp.143 - 152

Macroporous poly(N-ethylacrylamide) (PNEAM) hydrogels have been prepared in a methanol-water (1:1, v/v) mixture in the presence of 0, 0.05, 0.1, 0.15, and 0.2 M yttrium trifluoromethanesulfonate [Y(OTf)(3)] Lewis acid (LA) concentrations. SEM micrographs show that the resulted hydrogels are highly porous. Swelling ratios of all the hydrogels in water decrease with the increase in the temperature, and the hydrogels show lower critical solution temperature (LCST) volume phase transition at around 75 A degrees C. LCST of PNEAM homopolymers gradually increases with the increase in the isotacticity of the polymers. Moreover, the hydrogel . . .s show cononsolvency in different methanol-water mixtures at 50 A degrees C. Deswelling rate of the hydrogels prepared in the presence of LA is higher than the gel prepared in the absence of LA and this rate increases with increase in the LA concentration. The reswelling rate of the hydrogels also follows the same order, that is reswelling rate also increases with the increase in the LA loading in the gels. All these results are explained on the basis of the formation of the highly porous hydrogels with a higher isotactic PNEAM chain segment in a methanol-water mixture in the presence of LA Daha fazlası Daha az

Preparation of poly(ethylene glycol) grafted poly(3-hydroxyalkanoate) networks

Hazer, Baki | Lenz, W. Lenz | Çakmaklı, Birten | Borcaklı, Mehlika | Koçer, Halil

Article | 1999 | Macromolecular Chemistry and Physics200 ( 8 ) , pp.1903 - 1907

Poly(3-hydroxyalkanoate)-g-poly(ethylene glycol) crosslinked graft copolymers are described. Poly(3-hydroxyalkanoate)s containing double bonds in the side chain (PHA-DB) were obtained by co-feeding Pseudomonas oleovorans with a mixture of nonanoic acid and anchovy (hamci) oily acid (in weight ratios of 50/50 and 70/30). PHA-DB was thermally grafted with a polyazoester synthesized by the reaction of poly(ethylene glycol) with MW of 400 (PEG-400) and 4,4'-azobis(4-cyanopentanoyl chloride). Sol-gel analysis and spectrometric and thermal characterization of the networks are reported. © Wiley-VCH Verlag GmbH, 1999.

Efficacy of keratinocyte growth factor (palifermin) for the treatment of caustic esophageal burns

Numanoğlu, Kemal Varın | Tatlı, Duygu | Bektaş, Sibel | Er, Ebubekir

Article | 2014 | Experimental and Therapeutic Medicine8 ( 4 ) , pp.1087 - 1091

Current treatment strategies against the development of corrosive esophageal strictures remain unsatisfactory. Thus, the aim of the present study was to investigate the efficacy of keratinocyte growth factor, in the form of palifermin, for the prevention of stricture development following esophageal caustic injuries in a rat model. A total of 32 female Wistar albino rats were divided into four groups, which included the control (C), burn (B), steroid (S) and steroid plus palifermin (S/P) groups. An experimental corrosive esophageal burn model was established in the B, S and S/P groups. Weight gain was recorded and histopathological . . .evaluation was performed for each group. Weight gain in the S and B groups was compared with the control group and statistically significant differences were observed. In addition, statistically significant differences in weight gain were observed between the S/P group and the B group. Histopathologically, statistically significant differences were identified with regard to submucosal collagen deposition, muscularis mucosa and tunica muscularis damage when comparing the B group with the C group. In addition, statistically significant differences were observed when comparing the S and S/P groups with the B group. Furthermore, significant submucosal collagen deposition and tunica muscularis damage were observed in the S group when compared with the S/P group. The stenosis indexes in the C and S groups were significantly lower compared with the B group. In addition, the stenosis index in the S/P group was significantly lower compared with the S group. To the best of our knowledge, the present study is the first to investigate the effect of palifermin on corrosive esophageal burns. The addition of palifermin to the corrosive esophageal burn standard treatment regimen was found to reduce the degree of fibrosis and ameliorate histopathological damage in an experimental model of corrosive esophagitis in rats Daha fazlası Daha az

Water quality monitoring with emphasis on estimation of point and diffuse pollution sources

Albek, Erdem Ahmet | Göncü, Serdar | Uygun, Burcu Şimşek | Albek, Mine | Avdan, Zehra Yiğit | Güngör, Ömer

Article | 2019 | Global Nest Journal21 ( 2 ) , pp.163 - 171

Population growth, urbanization and anthropogenic activities are becoming a serious problem for water resources in Turkey, which necessitates their monitoring and maintenance of water quality. In this study, water quality was implemented in the Porsuk Stream in Inner Anatolia, Turkey. Water samples were collected at monthly intervals between the period of 2008-2010 at four selected stations. Twenty one water quality parameters were measured which are water temperature (T), pH, dissolved oxygen (DO), electrical conductivity (EC), salinity, turbidity, chloride, suspended solids, dissolved solids, organic nitrogen (Org-N), ammonium nit . . .rogen (NH3-N), nitrite nitrogen (NO2-N), nitrate nitrogen (NO3-N), total organic carbon, biological oxygen demand (BOD), chemical oxygen demand (COD), total coliform, alkalinity, orthophosphate phosphorus (PO4 3--P), total phosphorus and chlorophyll-a. The monitoring was conducted to see how the water quality changed along the stream in response to various anthropogenic activities. Besides, a paired t-test was utilized to determine the concentration differences at stations above and below the single most important point source of pollutants (Eskisehir city). Moreover, a regression model was used to establish relations between water quality parameters and flow and to estimate nonpoint source loadings. © 2019 Global NEST Printed in Greece Daha fazlası Daha az

A view from young oncologists on clinical trials in Turkey: Obstacles and solution proposals

Akman, Tulay | Tanrıverdı, Ozgur | Ozturk, Mehmet A. | Petekkaya, Ibrahim | Bakkal, Bekir Hakan | Sonmez, Ozlem U. | Avcı, Nilufer

Article | 2014 | Uluslararası Hematoloji-Onkoloji Dergisi24 ( 3 ) , pp.195 - 201

Günümüzde onkoloji alanında her geçen gün deneysel ve klinik araştırmaların sonucu olarak yeni bir gelişme olmaktadır. Kişi başına düşen yayın sayısına bakıldığında, Türkiye diğer gelişmiş Avrupa ülkelerinden epeyce geride yer almaktadır. Örneğin tüm dünyada kanser alanında yapılmış olan yayınların sayısı 2,134,964 iken, Türkiye’dekilerin sayısının toplamı 15.576’dır ve toplam yayın sayısı nüfus oranları ile karşılaştırıldığında diğer gelişmiş Avrupa ülkelerine göre epeyce geride kalmaktadır. Türkiye’de klinik çalışmaların önündeki en önemli engellerin finansal sorunlar, çalışma şartlarının zorlukları, iş yoğunluğu nedeniyle zaman k . . .ısıtlılığı, deneyimli-eğitimli insan gücü eksikliği, bilimsel çalışmanın tüm aşamalarında yardımcı olacak bir ekibin eksikliği, proje hazırlama ve etik kurul izin sürecinde yaşanan sıkıntılar, motivasyon eksikliği olduğu düşünülebilir. Biz genç onkologlar olarak bu yazımızda; dünya genelinde ülkemizin bilimsel ve klinik araştırmalardaki yerini, bilimsel araştırmaların yapılamamasının nedenlerini, ülkemizde yapılmakta olan yayınların çeşit ve kalitesini, bizim ülkemize ait varolan ger- çekleri ve bunlara yönelik getirilebilecek çözüm önerilerini tartışmayı amaçladık. There is a new improvement in oncology nearly in every day as a result of preclinical or clinical. As the number of publication per capita, Turkey is far behind the other developed European countries. For example, the number of publications in oncology field is 2.134.964 in the world, it is 15.576 in our country. The most important obstacles for clinical trials in Turkey may be listed as financial problems, difficulties of working conditions, time limitation due to work intensity, inadequate experienced/trained man-power, absence of assistance team at all steps of a scientific trial, difficulties faced during project planning and ethics committee submissions, and lack of motivation. In this article, we, as young oncologists, aimed to discuss the place of Turkey in areas of scientific and clinical trials in the world; underlying causes for inadequate number, type and quality of national studies and possible solution proposals in our countr Daha fazlası Daha az

Newly designed bioanode for glucose/O2 biofuel cells to generate renewable energy

Korkut, Şeyda | Kılıç, Muhammet Samet | Hazer, Baki

Article | 2019 | Asia-Pacific Journal of Chemical Engineering14 ( 6 ) , pp.195 - 201

A copolymer poly(methyl methacrylate-co-vinylferrocene) was synthesized and used for the first time in a biofuel cell design. Bioanaode enzyme glucose oxidase and biocathode enzyme bilirubin oxidase were physically immobilized onto the copolymer-modified electrodes. Characterization studies were conducted by scanning electron microscopy, carbon-13, fourier transform infrared and hydrogen-1 nuclear magnetic resonance, and cyclic voltammograms. The designed biofuel cell was operated with linear sweep voltammetry. The maximum current was at 45°C with 120 µg of polymer amount. An improved power density of 323 µW cm-2 that is higher than . . . other ferrocene-based fuel cells was obtained with 10-mM glucose at 0.4 V with the designed bioanode. © 2019 John Wiley & Sons Ltd Daha fazlası Daha az

Partial purification and characterization of an extracellular metallopeptidase produced by bacillus amyloliquefaciens FE-K1

Erem, Fundagül | İnan, Mehmet | Karakaş Budak, Barçın | Certel, Muharrem

Article | 2020 |

The aim of this study was to purify and characterize the peptidase of Bacillus amyloliquefaciens (Fukumoto) (strain FE-K1) isolated from ropey bread. Peptidases were purified from crude enzyme solution by affinity chromatography with an efficiency of 25 % and a purification coefficient of 1.53. The optimum pH of partially purified peptidase (PPPase) solution was determined as 7.5 and the peptidases retained approximately 90 % of their initial activity in the pH range 7.0-8.5 following incubation at 37°C for 2 h. The optimum temperature for the PPPase was 60°C. The approximate molecular weight of the PPPase was determined as 36 kDa. . . .Inactivation of the PPPase in the presence of O-FEN and EDTA showed them to be metallopeptidases and 5 mM of K+1 and 5 mM of Mn+2 ions increased the enzyme activity by 4 % and 6.15 %, respectively. The presence of Hg+2, Fe+3 and SDS (0.1-1.0 % w/v) caused inactivation whereas the enzyme retained most of its activity in the presence of 0.1-1.0 % (v/v) Triton X-100, Tween 20 and Tween 80 and 1-20 % (v/v) xylene, ethanol, acetone and acetonitrile. Characterization of the PPPase revealed the enzyme as a neutral serine metallopeptidase compatible with some organic solvents and surfactants Daha fazlası Daha az

Effect of ozone oxidative preconditioning in preventing early radiation-induced lung injury in rats

Bakkal, Bekir Hakan | Gultekin F.A. | Guven B. | Turkcu U.O. | Bektas S. | Can M.

Article | 2013 | Brazilian Journal of Medical and Biological Research46 ( 9 ) , pp.789 - 796

Ionizing radiation causes its biological effects mainly through oxidative damage induced by reactive oxygen species. Previous studies showed that ozone oxidative preconditioning attenuated pathophysiological events mediated by reactive oxygen species. As inhalation of ozone induces lung injury, the aim of this study was to examine whether ozone oxidative preconditioning potentiates or attenuates the effects of irradiation on the lung. Rats were subjected to total body irradiation, with or without treatment with ozone oxidative preconditioning (0.72 mg/kg). Serum proinflammatory cytokine levels, oxidative damage markers, and histopat . . .hological analysis were compared at 6 and 72 h after total body irradiation. Irradiation significantly increased lung malondialdehyde levels as an end-product of lipoperoxidation. Irradiation also significantly decreased lung superoxide dismutase activity, which is an indicator of the generation of oxidative stress and an early protective response to oxidative damage. Ozone oxidative preconditioning plus irradiation significantly decreased malondialdehyde levels and increased the activity of superoxide dismutase, which might indicate protection of the lung from radiation-induced lung injury. Serum tumor necrosis factor alpha and interleukin-1 beta levels, which increased significantly following total body irradiation, were decreased with ozone oxidative preconditioning. Moreover, ozone oxidative preconditioning was able to ameliorate radiation-induced lung injury assessed by histopathological evaluation. In conclusion, ozone oxidative preconditioning, repeated low-dose intraperitoneal administration of ozone, did not exacerbate radiation-induced lung injury, and, on the contrary, it provided protection against radiation-induced lung damage Daha fazlası Daha az

Optimization of ELISA and immunoblot methods for the detection of igg antibodies against old world hantaviruses in wild rodents

Polat, Ceylan | Karataş, Ahmet | Sözen, Mustafa | Matur, Ferhat | Abacıoğlu, Hakan | Öktem, Mehmet Ali

Article | 2016 | Mikrobiyoloji Bülteni50 ( 2 ) , pp.245 - 255

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