IZTECH Research Centers Collection / İYTE Araştırma Merkezleri Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/11147/2636
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Article Isıl Konfor Sıcaklıklarına Bağlı Olarak Bir Konutun Enerji Performansının Değerlendirmesi: Izmir Örneği(Sakarya Üniversitesi, 2018) Yıldırım, Nurdan; Kuzgunkaya, Ebru; Gökçen Akkurt, GüldenTürkiye’de enerji tüketiminin yaklaşık %34’ü binalarda ve bunun %85 kadarı da ısıtma ve soğutma amaçlı kullanılmaktadır. Binalarda bulunan HVAC sistemlerinin işletme özellikleri, hem binanın ısıl konforunu hem de enerji tüketimlerini doğrudan etkilemektedir. Bu çalışmada, HVAC sistemlerinin işletme şartlarının, ısıl konfor koşulları ile enerji tüketimlerine olan etkisinin belirlenmesi amaçlanmaktadır. Bu amaçla İzmir ilindeki 100 m2’lik bir konut için öngörülen HVAC sisteminin kesikli ve sürekli rejimde, tek ve çift sıcaklık set değerleri ile tam mekanik kontrollü veya doğal havalandırmalı olarak çalıştırılması durumları incelenmiştir. Isıl konfordan olan memnuniyet; Tahmini Ortalama Oy (Predicted Mean Vote - PMV) değeri ile ifade edilmektedir. Bu kapsamda öncelikle, Design Builder yazılımı kullanılarak en iyi duruma karşılık gelen PMV=0’a göre HVAC sisteminin set sıcaklıları belirlenmiştir. Bu sıcaklık set değerlerinin kullanılması ile ele alınan 5 farklı durumda konut için yıllık birim ısıtma/soğutma enerji tüketimleri, birim birincil enerji tüketimi, yıl boyunca ailenin evde bulunduğu saatlerde sağlanan PMV değerleri ve PMV değerlerinin istatistiksel değerlendirilmesi gerçekleştirilmiştir. Elde edilen sonuçlara göre, incelenen 5 durum arasında normal beklenti seviyesinde % 99,6 kümülatif frekans yüzdesi ile ısıl konforu en çok sağlayan tam mekanik kontrollü, sürekli rejim, aylık çift ısıtma/soğutma operatif sıcaklık set değerli durumdur. Tam mekanik kontrollü, kesikli rejim, aylık tek ısıtma/soğutma hava sıcaklığı set değerli durum ise 2,04 kWh/m2/%KF birim memnuniyet enerji tüketimi değeri ile en az enerji tüketen durum olmaktadır.Article Citation - WoS: 10Citation - Scopus: 9Bi̇yomalzemelerden İ̇zole Edi̇len Staphylococcus Epidermidis Suşlarinin Yüzey Özelli̇kleri̇ni̇n Beli̇rlenmesi̇(Ankara Mikrobiyoloji Derneği, 2010) Sudağıdan, Mert; Erdem, İlker; Çavuşoğlu, Cengiz; Çiftçioğlu, MuhsinThe surface properties of bacteria play an important role on adhesion to the biomaterial surface. In this study, the surface properties of Staphylococcus epidermidis strains isolated from clinically used polymeric biomaterial surfaces were investigated on the basis of zeta potential, hydrophobicity and surface topography. A total of 10 S.epidermidis strains isolated from intravenous catheters (n= 5), endotracheal tubes (n= 3) and central venous catheters (n= 2) which were used in the patients of pulmonary Intensive Care Unit, Ege University Medical Faculty Hospital, were included to the study. Seven of those isolates were biofilm producers, inhabiting biofilm genes, 2 were non-biofilm producers, however, inhabiting biofilm genes, and 1 was non-biofilm producer, inhabiting no biofilm genes. Zeta potential analysis have been performed in 3 different buffers (phosphate-buffered saline, 1 mM potassium chloride and 1 mM potassium phosphate buffer) and at different pH values (pH 4.1-8.2), in order to simulate in vivo environment of the biomaterials. Hydrophobicities of the strains were examined by bacterial adhesion to hydrocarbon (BATH) test and the surface topography of biofilms and slime layers were visualized by atomic force microscopy (AFM) and scanning electron microscopy (SEM) methods. It was found that all strains have negative zeta potential values (surface charge) in all buffers and pH values. In hydrophobicity analysis, the highest value (86%) was determined for non-biofilm forming S.epidermidis strain YT-169b (endotracheal tube isolate) and the lowest hydrophobicity (2.5%) was determined for biofilm forming S.epidermidis strain YT-212 (central venous catheter isolate). Biofilm and slime layers of the strains were imaginated by AFM and SEM analysis in ?m scale. SEM analysis showed that bacteria highly adhered to rough surfaces on biomaterial surfaces and the produced slime layers covered the surface of bacteria. In conclusion, elucidating the surface properties of opportunistic pathogens in different physiologic buffers will give important clues for the production of non-adhesive materials and antibacterial surfaces for those bacteria. It was also estimated that designing the surface of the biomaterial to have negative surface charge in the body and to be as smooth as possible will hamper biofilm formation.Article Citation - WoS: 19Citation - Scopus: 18Biyomalzeme Yüzeylerinden İzole Edilen Metisiline Dirençli Staphylococcus Aureus Suşlarında Virülans Genlerinin Araştırılması(Ankara Microbiology Society, 2008) Sudağıdan, Mert; Çavuşoğlu, Cengiz; Bacakoğlu, FezaStafilokoklar, biyomalzeme kaynaklı nozokomiyal enfeksiyonların en önemli etkenlerindendir. Bu çalışmada, Göğüs Hastalıkları Yoğun Bakım Ünitesi (YBÜ)'nde yatan 48 hastada kullanılan polimerik biyomalzeme yüzeylerinden izole edilen metisiline dirençli 11 Staphylococcus aureus suşunda virülans genlerinin varlığının saptanması ve bunların bazılarının fenotipik ifadelerinin araştırılması amaçlanmıştır. Çalışmamızda polimeraz zincir reaksiyonu (PCR) ile özgül primerler kullanılarak, bağlanma ve biyofilm oluşumundan sorumlu genler (icaA, icaC, bap), metisilin direnç geni (mecA), enterotoksin A-E üretiminden sorumlu genler (sea, seb, sec, sed, see), toksik şok sendromu toksini geni [tst), eksfoliatif toksin A ve B genleri (eta ve etb), alfa ve beta-hemolizin genleri (hla ve hlb), stafilokokal ekzotoksin benzeri protein-1 geni (sef1), proteaz genleri (sspA, sspB, aur, serine proteaz geni), lipaz geni (geh) ve regülatör genler (sarA ve agrCA) araştırılmıştır. Ayrıca suşların fenotipik olarak biyofilm oluşturma, antibiyotik duyarlılık, proteaz ve lipaz üretimi gibi özellikleri de değerlendirilmiştir. Biyofilm testlerinde, biyofilm yapan ve "slime" üreten suşlara rastlanmamış, ancak tüm suşların biyofilm yapımında rol oynayan icaA genine sahip olduğu bulunmuştur. Bununla birlikte biyofilm yapımında rol oynayan icaC ve bap genleri tespit edilememiştir. Tüm suşlarda mecA geninin varlığı saptanmış ve suşların hepsinin oksasilin, penisilin G ve gentamisine; 10'unun eritromisine ve dokuzunun da ofloksasine dirençli olduğu bulunmuştur. İzolatların tümü vankomisin, teikoplanin ve ko-trimoksazole duyarlı olarak saptanmıştır. Ekzotoksin ve regülatör genlerinin taranması sonucunda, suşların sea, seti, hla, hlb ve sarA genlerini taşıdığı belirlenmiştir. PCR ile tüm suşların, çalışılan bütün proteaz genlerine (sspA, sspB, aur ve serin proteaz geni) sahip olduğu görülmüş, ancak sütlü (skim milk ve milk agar) ve kazein ağarlarda yapılan proteaz üretimi testlerinde negatif sonuç alınmıştır. Lipaz üretiminin belirlenmesi için Tween 20, Tween 80 ve tributyrin içeren besiyerleri kullanılmış ve tüm suşlarda geç dönemde (inkübasyonun üçüncü günü) pozitif sonuç alınmasına karşın, izolatların hiçbirisinde lipaz üretiminden sorumlu geh geni bulunmamıştır. Sonuç olarak, biyomalzeme yüzeylerinden izole edilen S.aureus suşlarında, araştırılan virülans genlerinden bazılarının varlığı saptanmış, ancak bunların tam olarak fenotipe yansımadığı izlenmiştir. İzolat sayısının azlığına ve tüm genlerin ekspresyonlarının fenotipik olarak çalışılamamış olmasına rağmen, bu genlerin varlığının yoğun bakım hastalan için potansiyel bir risk teşkil edebileceği düşünülmüştür.Article Citation - WoS: 9Citation - Scopus: 13X-Ray Fluorescence Spectroscopic Determination of Heavy Metals and Trace Elements in Aerial Parts of Origanum Sipyleum L From Turkey(Pharmacotherapy Group, 2016) Durmuşkahya, Cenk; Alp, Hakan; Hortooğlu, Zehra Sinem; Toktaş, Ümit; Kayalar, HüsniyePurpose: To determine the heavy metal and trace element composition of the powdered aerial parts of Origanum sipyleum L. and its water extract. Methods: The heavy metal and trace elements content of the powdered plant material and 2% aqueous extract were evaluated by x-ray fluorescence spectroscopy with silicon drift detector SDD at a resolution of 145 eV and 10,000 pulses. The process conditions were 0.1 g sample weight, process time of 300 s at a voltage of 25 kV and 50 kV, and at a current of 0.5 and 1.0 mA under helium atmosphere. Results: The major elements, K, Ca and Na, known as macronutrients, constituted 11990, 10490 and 970 ppm of the powdered drug and 8910, 2991 and 810 ppm of the water extract, respectively. Among other constituents, arsenic, lead and uranium levels were < 1, 2.1 and < 3 ppm, respectively, in the powdered material while in the aqueous extract, the levels were < 1, < 2 and 200 ppm, respectively. Conclusion: O. sipyleum is a potential source of macro- and micronutrients from which useful food additives and health supplements can be derived.Article Citation - Scopus: 1Prognostic Significance of the Igvh Mutation Status and Immunohistochemical Analysis of Zap70 and Cd38 in Bone Marrow Biopsies in Chronic Lymphocytic Leukemia(Türkiye Klinikleri Journal of Medical Sciences, 2014) Kahraman Çetin, Nesibe; Kaçar Döger, Füruzan; Kurtgöz, Serkan Erkan; Rusçuklu, Dane; Yavaşoğlu, İrfanObjective: Chronic lymphocytic leukemia (CLL) is one of the most common leukemia type among adults in the industrialized countries. Due to the nature of CLL, it is important to recognize patients with a more rapid course of disease. The goal of our study was to study ZAP70 and CD38 antibodies along with immunglobulin heavy chain variable region (IgVH) mutation status, which have been associated with rapid progression and aggressive clinical course in CLL, and to correlate the expression of these molecules with patterns of bone marrow infiltration. Material and Methods: We included 84 bone marrow biopsy samples into the study to determine ZAP70 and CD38 status using immunohistochemistry. Expression patterns for both antibodies were then correlated with the bone marrow infiltration patterns. We also analyzed IgVH mutations in 20 patients using DNA obtained from paraffin-embedded formalin-fixed bone marrow biopsies. These findings were then correlated with immunohistochemical results. Results: We identified a positive correlation between the expression patterns of ZAP70 and CD38, factors that were previously identified as poor prognostic factors (p<0.001). However, there was no correlation between these two markers and IgVH mutation status (p=1.000 and p=0.931). In addition, we showed a statistically significant positive correlation with ZAP70 immunostaining, and the necessity for an early intervention (p=0.046). ZAP70 and CD38 expressions were statistically significantly correlated with the diffuse pattern infiltration of bone marrow (p<0.001 and p<0.001, respectively). Conclusion: Despite small number of our patients, the findings of our study suggested that ZAP70 and CD38 expression patterns as well as IgVH mutation status might be helpful to determine the course of the disease, and the risk of progression. Particularly ZAP70 immunopositive patients appear to have a faster disease progression, and may require earlier intervention and a closer follow up.Article Citation - Scopus: 19Application of Geothermal Energy and Its Environmental Problems in Turkey(Inderscience Enterprises Ltd., 2015) Baba, AlperHuman beings have been benefiting from geothermal energy for different uses since the dawn of the civilisation in many parts of the world. One of the earliest uses of geothermal energy was for heating and it was used extensively by Romans in Turkey. The Aegean region is favoured by a large number of thermal springs known since ancient times. However, it was first in the 20th century that geothermal energy was used on a large scale for direct use and electricity generation. The country's installed heat capacity is 2,705 MWt for direct use and 322.39 MWe for power production. In parallel to developing geothermal energy applications in Turkey, many sites are now experiencing problems such as water contamination associated with geothermal fluid. Especially, the high temperature solution of elements and compounds, causes operational limitations in geothermal power plants. These limitations are due to the severe scaling and corrosion of geothermal fluid. Copyright © 2015 Inderscience Enterprises Ltd.Article Mineral Compositions of Some Selected Centaurea Species From Turkey(Chemical Publishing Co., 2014) Kayalar, Hüsniye; Durmuşkahya, Cenk; Hortooğlu, Zehra SinemCentaurea calolepis Boiss., Centaurea lydia Boiss. and Centaurea polyclada DC. were investigated for major minerals and trace elements by X-ray fluorescence spectrometry. Calcium and potassium were found in maximum concentrations in Centaurea species. The results revealed that the concentrations of iron, manganese and zinc were found to be high in C. calolepis. On the other hand, copper, magnesium and phosphorous were found in higher concentrations in C. polyclada. Mineral composition of Centaurea species, will be descriptive in terms of the traditional use of this species. In addition, C. calolepis, C. lydia and C. polyclada may be utilized in nutraceuticals as potential natural sources of major minerals and trace elements.Article Citation - WoS: 3Citation - Scopus: 7Elemental Analysis of Galium Incanum Sm Subsp Centrale Ehrend by X-Ray Fluorescence Spectroscopy(Pharmacotherapy Group, 2013) Kayalar, Hüsniye; Durmuşkahya, Cenk; Hortooğlu, Zehra SinemPurpose: To evaluate the content of trace elements in Galium incanum SM. subsp. centrale Ehrend. Methods: The air-dried aerial parts of the plant material were used and its water extract (2 % w/v infusion) was analysed for trace elements using x-ray fluorescence (XRF) spectrometry. Results: The aqueous extract depicted significant concentrations of macro- and micro-nutrients with heavy metal and metal oxide content of 4.07 - 6.02 and 3.19 - 4.01 % for powdered plant material and water extract, respectively. The contents of Ca (22840 ppm) and K (8204 ppm) were the highest among all the elements while Zn (45.9 ppm) and Fe (328 ppm) were also detected in significant amounts. Zn, Mn and Cu showed the highest content while those of Mg, Al, K, Ca, Fe and P lowest in the water extract. Conclusion: The presence of significant levels of Ca, K, Na, Fe, Zn, Mg, Mn and Cu in G. incanum subsp. centrale showed that this plant has notable nutrient elements. The traditional use of Gallium species as a diuretic may be attributed to its rich content of potassium.Article Citation - WoS: 20Citation - Scopus: 20Screening Virulence Properties of Staphylococci Isolated From Meat and Meat Products(B W K Public Relations, 2009) Sudağıdan, Mert; Aydın, A.Virulence properties (biofilm formation, antibiotic susceptibility, production of extracellular enzymes and the presence of toxin genes) of staphylococci isolated from various meat and meat products were investigated. 22 Staphylococcus spp. (S. aureus n = 9, S. haemolytlcus n = 4, S. cohnii n = 3, S. saprophytics n = 3, S. hominis n = 1, S. simulans n = 1 and S. warneri n = 1) were isolated from 120 meat and meat product samples. 10 strains were biofilmformers. Although none of the strains was resistant to vancomycin, oxacillin, teicoplanin, ofloxacin and gentamicin, 8 strains were found to be resistant to penicillin and one strain was found to be resistant to erythromycin. In addition, all strains were negative for the mecA PCR. 8 strains showed lipolytic activity against Tween 80,10 strains against Tween 20, and 18 strains against tributyrin. Moreover, 9 strains showed proteolytic activity against casein, 11 strains against milk and 17 strains against skim milk containing media. Mostly S. aureus strains showed positive results for icaA-SA, nuc, geh, sspA, sspB, aur, serine protease gene, hla, hlb, set1, and etb. However, 7 of coagulase-negative staphylococci strains were found to carry see gene. As both prevalence and concentration of this bacterium were low, and no isolate contained all virulence factors, it is concluded that common hygiene and process control measures should be sufficient to control meatborne staphylococcal intoxication.