Showing papers by "Mustafa Demirci published in 2014"

Bacterial penetration of restored cavities using two self-etching bonding systems

Abstract: Objective: The aim of this study was to investigate the effects of two bonding systems, with and without antibacterial monomers, on marginal bacterial and dye leakage. Materials and Methods: Class V cavities were prepared in extracted teeth for a bacterial leakage test, and the teeth were sterilized using a steam autoclave. Four cavities were not restored for the controls, and the other teeth were divided into two groups ( n = 16 cavities each): Clearfil Protect Bond group (CPB) and Clearfil SE Bond group (CSE). After application of the bonding agent, the cavities were restored using a composite resin (Clearfil AP-X). The teeth were thermocycled, stored in a broth culture of 1.56 Χ 108 colony forming units (CFU)/ml of Streptococcus mutans at 37°C for 10 days, and subsequently processed for bacterial staining. Sections from the demineralized teeth were evaluated under a light microscope. In the dye leakage test, the cavities were restored as described in the bacterial penetration test. After thermocycling, the teeth were immersed in 5% basic fuchsin for 24 h, and then divided in half and observed under a stereomicroscope. The data were analyzed using the Kruskal-Wallis and Mann-Whitney U-tests ( P = 0.05). Results: The bacterial stain was detected at the cavity wall of five cavities in both bonding systems. Additionally, two cavities in the CSE group, one cavity in the CPB group, and all control cavities showed bacterial staining within the cut dentinal tubules. Dye staining at the axial cavity wall was detected in only three of the teeth for both bonding systems. Conclusion: The bonding systems used in this study provided an acceptable marginal seal to prevent bacterial and dye leakage.

Smart grid on energy efficiency application for wastewater treatment

Abstract: In this study, first, designing and operating conditions of a wastewater treatment plant located in the south of Iskenderun of Hatay, Turkey, is examined and analyzed. It is shown that influent pumps have large part of energy consumption in plant. Second, some simulation and experimental studies were performed on plant. Energy efficiency and plant optimization have provided 40% of energy consumption. Also, experimental study is simulated by Matlab Fuzzy LogicController. The experimental results are in good agreement with the simulation results. © 2013 American Institute of Chemical Engineers Environ Prog, 33: 556–563, 2014

Experimental investigation of cross-shore sandbar volumes

Abstract: Sandbars are critical to the cross-shore movement of sediment. Prediction of cross-shore sandbar volumes requires knowledge about the functional relationship of sediment transport rate conditions with waves, currents, base slope, sediment property and water depth. In this study, experiments on cross- shore sediment transport were carried out in a laboratory wave channel for initial base slopes of 1/8, 1/10 and 1/15. Using regular waves with different deep-water wave steepness generated by a pedal-type wave generator, bar volumes caused by cross-shore sediment transport are investigated for beach materials with the medium diameter of d50 = 0.25, 0.32, 0.45, 0.62 and 0.80 mm. A non-dimensional equation for sandbar volume was obtained by using linear and non-linear regression methods through the experimental data and was compared with previously developed equations in the literature. The results have shown that the experimental data fitted well to the proposed equation with respect to the previously developed equations.

Pricing policies as a marketing strategy in the construction industry: case study of turkish companies

Abstract: The firms in the construction industry have to determine pricing and promotion policies, then these policies must be carefully and systematically integrated with the marketing strategies. Not only the demand and cost are important in pricing decisions but competition is also a significant variable to be considered. To determine the difficulties and the affecting factors in applying pricing decisions within the marketing concepts in construction sector, a survey was carried out among the Turkish companies as a sample group. In total 49 companies, mostly medium-size firms have been surveyed. The responses of firms are considered based on their actively engaged subsectors, namely, residential, commercial/public buildings, and infrastructure construction. The answers of firms are also evaluated based on their stated organizational structure, namely, simple, hierarchical, project, and network. The views about the various aspects of pricing policy development in phases, for example before and during bid...

Changes in resistance percentage to antibiotics in Pseudomonas aeruginosa and Acinetobacter baumannii strains isolated from blood cultures of intensive care unit patients

Abstract: Objective: Infections of Pseudomonas aeruginosa and Acinetobacter baumannii are one of the greatest concerns for hospitalized patients, particularly those in intensive care units (ICUs). The aim of this study was to determine the antimicrobial resistance percentages and to assess empirical treatment options for bloodstream infections due to P. aeruginosa and A. baumannii strains in ICU patients. Methods: Resistance percentages of strains isolated in JanuaryDecember 2010 and JanuaryDecember 2011 were separately analyzed and compared. The differences in resistance percentages between two intervals was statistically analyzed. Results: A statistically significant decrease was found in the resistance percentage of piperacillin-tazobactam, cefoperazone-sulbactam, ceftazidime, ciprofloxacin, gentamicin, amikacin and netilmicin in the second period compared with the first (p values were 0.0059, 0.0000, 0.0048, 0.00350, 0.0000, 0.0000, 0.0003, respectively) for P. aeruginosa strains. Whereas resistance percentage of aztreonam was increased (p value was 0.0155). Resistance percentage of imipenem was found similar. ÖZET Amaç: Pseudomonas aeruginosa ve Acinetobacter baumannii enfeksiyonları özellikle yoğun bakım ünitesinde (YBÜ) yatan hastalar için en önemli sorunlardan birisidir. Bu çalışmanın amacı, YBÜ hastalarında kan dolaşımı enfeksiyonlarına sebep olan P. aeruginosa ve A. baumanni etkenlerinin antimikrobiyal direnç paternlerini belirlemek ve ampirik tedavi protokollerinin uygunluğunu değerlendirmektir. Yöntemler: Ocak-Aralık 2010 ve Ocak-Aralık 2011 tarihlerinde YBÜ’de yatan hastalara ait hemokültür örneklerinde üreyen suşların direnç oranları ayrı ayrı incelenerek karşılaştırıldı. Bu iki zaman aralığı arasında direnç oranlarındaki farklılıklar karşılaştırılarak istatistiksel olarak analiz edildi. Bulgular: P. aeruginosa suşlarının piperasilintazobaktam, sefaperazon sulbaktam, seftazidim, siprofloksasin, gentamisin, amikasin ve netilmisine direnç oranlarında 2011 yılında 2010 yılına oranla azalma olduğu saptandı (p değerleri sırasıyla, 0,0059, 0,0000, 0,0048, 0,0350, 0,0000, 0,0000, 0,0003). Buna karşılık, aztreonam direnç oranında artış saptandı (p değeri, 0,0155). İmipenem direncinin benzer oranlarda Geliş Tarihi / Received : Kabul Tarihi / Accepted : İletişim / Corresponding Author : Berrin UZUN İzmir Katip Çelebi Üni., Atatürk Eğitim ve Araştırma Hast., Tıbbi Mikrobiyoloji Lab., İZMİR Tel : +90 232 244 44 44-1982 E-posta / E-mail : berrinuzun@gmail.com 31.07.2013 02.01.2014 Türk Hijyen ve Deneysel Biyoloji Dergisi DOI ID : 10.5505/TurkHijyen.2014.68916 Uzun B, Güngör S, Sezak N, Afşar İ, Şerifhan-İlgün M, Demirci M. Yoğun bakım hastalarının kan kültürlerinden izole edilen Pseudomonas aeruginosa ve Acinetobacter baumannii izolatlarının antibiyotik direnç yüzdelerindeki değişim. Turk Hij Den Biyol Derg, 2014; 71(1): 1-8. Changes in resistance percentage to antibiotics in Pseudomonas aeruginosa and Acinetobacter baumannii strains isolated from blood cultures of intensive care unit patients Cilt 71  Sayı 1  2014 2 Nosocomial infections pose a threat in difficult to treat patients, especially in the high-risk departments such as Intensive Care Units (ICUs) (1). Bloodstream infections are being reported as a leading cause of morbidity and mortality worldwide. Moreover, bloodstream infections represent about 15% of all nosocomial infections and causes of health care costs (2, 3). Pseudomonas aeruginosa and Acinetobacter baumannii are nonfermentative gram-negative bacteria that have minimal nutritional requirements and can survive on a wide variety of surfaces and in aqueous environments. Infections with P. aeruginosa or A. baumannii are of greatest concern for hospitalized patients, particularly those in ICUs, where these opportunistic pathogens are capable of developing severe invasive infections in critically ill and immunocompromised patients (4). In recent years, multiple antimicrobial resistance patterns of these bacteria have become as a major problem and a factor that complicates the treatment (5). Uncontrolled and intensive use of antimicrobials is one of the most important reasons for the increase of resistant strains. Each hospital should have data about their antimicrobial susceptibility patterns of nonfermentative bacteria to choose appropriate empirical treatment regimens for reducing morbidity and mortality. To have data about resistance percentage is required not only for assessment of treatment options but also to monitor the spread of resistant organisms or resistance genes throughout the hospital and community. Therefore each hospital must regularly follow their isolates, determine resistance percentage of antibiotics and regulate their own empirical treatment protocols according to these results (6). The present study was designed for this aim. INTRODUCTION RESISTANCE OF PSEUDOMONAS AERUGINOSA AND ACINETOBACTER BAUMANNII Turk Hij Den Biyol Derg olduğu görüldü. A. baumannii suşlarının sefepim ve amikasin direnç oranlarında ikinci periyotta ilkine oranla istatistiksel olarak anlamlı azalma saptandı (p değerleri, 0,0003 ve 0,0000). Ampisilin-sulbaktam, piperasilintazobaktam ve imipeneme karşı direnç oranlarında artış saptandı (p değerleri sırasıyla, 0,0003, 0,0210, 0,0033). Her iki bakteri türünde de kolistine direnç saptanmadı. A. baumannii izolatlarında tigesiklin direnci saptanmadı. Sonuç: Her hastanenin özellikle yoğun bakım birimlerinden izole edilen suşların antibiyotik direnç paternlerinin aktif sürveyansla takibi, ampirik tedavi yaklaşımlarını belirlemeye hizmet eder. Bu çalışmada antibiyotik kullanım politikasının hastane enfeksiyonları ile mücadelede önemli bir adım olduğu vurgulanmıştır. Sonuç olarak, direnç oranlarını azaltmak için, enfeksiyon kontrol önlemleri alınmalı, ampirik tedavi rejimleri sürekli gözden geçirilmeli ve aktif surveyans verilerine göre belirlenmelidir. Anahtar Sözcükler: Acinetobacter baumannii, Pseudomonas aeruginosa, antibiyotik direnci, kan kültürü, yoğun bakım ünitesi In A.baumannii strains, a statistically significant decrease was found in resistance percentage of cefepime and amikacin in the second period compared with the first (p values were 0.0003, 0.0000). Resistance percentage of ampicillin-sulbactam, piperacillin-tazobactam and imipenem was increased (p values were 0.0003, 0.0210, 0.0033). There was no colistin resistance determined in both species. Tigecycline resistance was not found in A. baumannii isolates. Conclusion: Active surveillance of antibiotic resistance percentages of isolated strains especially in ICUs serves to determine empirical treatment regimens in every institution. The present study emphasized that antibiotic usage policy is an important step to combat hospital infections. Consequently, infection control measures should be taken, empirical treatment regimens should be constantly reviewed, and should be determined according to active surveillance data in order to decrease resistance percentages.

Effect of saliva contamination on shear bond strength and microleakage of one-bottle etch-and-rinse and self-etch adhesives: scanning electron and confocal laser microscopic analyses

Abstract: Purpose: To evaluate the effect of saliva contamination on shear bond strength, microleakage, and microstructure of the adhesive interface in two different adhesive systems by using scanning electron microscopy (SEM) and confocal laser microscopy (CLSM). Materials and methods: Randomly, 228 third molars were allocated to six groups for an etch-and-rinse adhesive One-Step Plus (Bisco Inc.) and a self-etch adhesive G Bond (GC Corp.): Group 1 – manufacturer’s instructions were followed; Group 2 – involved contamination and drying before adhesive application; Group 3 – involved contamination, washing, and blot drying before adhesive application; Group 4 – involved contamination, etching, washing, and blot drying before adhesive application; Group 5 – involved contamination and drying after adhesive application, followed by adhesive reapplication; Group 6 – involved contamination and washing after adhesive application, followed by adhesive reapplication. Shear bond strength was tested after specimens were stor...

Effect of different dentin adhesives and application modes on sealing ability of amalgam restorations

Abstract: Purpose: The aim of the study was to evaluate the sealing ability of bonded amalgam restorations using different adhesive materials with different adhesive application methods including amalgam bonding application. Materials and methods: The prepared Class-V cavities were randomly assigned to four application groups of four tested dual-curing dentin adhesives (Scotchbond Multi-Purpose Plus, XP Bond, Xeno IV and Clearfil Liner Bond 2V), dual-curing resin-based cement (Panavia F2.0) and a control group (unlined amalgam). Group 1 adhesives were applied according to the instructions for direct light-curing, Group 2 chemical-curing mode was applied according to the manufacturer’s amalgam bonding instructions. Group 3 adhesives were first applied in light-curing mode, and then amalgam bonding adhesive was applied. Group 4 adhesives were first applied in chemical-curing mode, followed immediately by light-curing mode. After that, amalgam adhesive parts were applied; then, the amalgam was condensed and carved. Af...

The influence of retention hole and adhesive systems on the shear bond strengths of resin composite to amalgam

Abstract: The aim of the study is to evaluate the influence of surface-treatment methods with and without the use of a retention hole on the shear bond strength of a resin composite adhered to amalgam using an adhesive system. Amalgam specimens were divided into six groups. Group 1 (Bur) specimens were roughened with a diamond bur, Group 2 (Al2O3) specimens were sandblasted with a 50 μm aluminum oxide powder, Group 3 (CoJet®) specimens were sandblasted with 30 μm CoJet® Sand, Group 4 (Bur + Rh) specimen surfaces were prepared with a retention hole 1 mm in diameter and 1 mm deep and roughened with a diamond bur, Group 5 (Al2O3 + Rh) specimens were also prepared with a retention hole and sandblasted with 50 μm aluminum oxide powder, and Group 6 (CoJet® + Rh) surfaces were prepared with a retention hole and sandblasted with 30 μm CoJet® Sand. Resin composite cylinders were bonded onto the amalgam surfaces using Xeno® IV, Optibond™ All-In-One, Clearfil™ SE Bond, Adper™ Single Bond Plus, and Scotchbond™ Multi-Purpose ad...

Simulation of Density Flow and Velocity Variation in Dam Reservoirs

Abstract: Investigations and observations indicate that variation in density and underflow is related to the formation of flows in the dam reservoirs. The hydrodynamics of density currents and plunging are difficult to study in the natural environment and laboratory condition due to small-scale, entrainment and turbulent flows. Correct estimation of dam reservoir flow, density flow dynamics, plunging and velocity variations are very important for the dam reservoir sedimentation and water quality problem. Therefore, the two-dimensional model is adapted to simulate density plunging flow simulation through a reservoir with sloping bottom. The model is developed using nonlinear and unsteady continuity, momentum, energy and k-e turbulence model equations in the Cartesian coordinates. The equations of the model are solved based on the initial and boundary conditions of the dam reservoir flow. Velocity, temperature and turbulence viscosity variation through the dam reservoir, effects of density flow parameters such as plunging depths, plunging points, mixing rate can be determined from the simulation results. In this study, the velocity variations through a reservoir with sloping bottom are defined and compared with the previous experimental work and the mathematical models.

The investigation and typing of human papillomavirus by molecular microbo- logical method and evaluation of cytological results in cervical smears

Abstract: Introduction: Aims: HPV-DNA testing is widely used throughout the world and today is an important part of cervical cancer screening programs. In this study, it was aimed the investigation of the presence and typing of HPV-DNA by using real time polyme- rase chain reaction (PCR) in the cervical samples of women with risk factors in terms of HPV and the evaluation of compliance of identified HPV types with results of cervical smear. Methods: HPV-DNA results were analyzed between January 2009 and December 2012 retrospectively. Results: HPV-DNA detection rate was 48% at the cervical samples. The positive samples were described HPV-16 in 26.5%, HPV-18 in 5.5%, non-HPV-16-18 (HPV-31, HPV-35, HPV-59) in 40%, potential HR-HPV (HPV-66) in 1.5% and LR-HPV (HPV-6, HPV-11) in 27.5%. In the cytological examination, %15 (n: 54) samples were evaluated as positive for intraepithelial lesion. These was determined as ASCUS (Atypical Squamous Cells of Undetermined Significance) in 18% (n: 10), LSIL (Low-grade Intraepithelial Lesion) in 50% (n: 27), HSIL (High-grade intraepithelial lesion) in 30% (n: 16), squamous cell carcinoma in 2% samples. In the samples that intraepitelyal lesion was positive but undetermined HPV-DNA, 5 samples were identified as ASCUS and 13 samples were LSIL. Cytological abnormality was found in the 23.4% of 128 detected samples to HR-HPV and potential HR-HPV; in 12.2% of 49 detected samples to LR-HPV and in 9.3% of 194 undetected samples to HPV-DNA. In the samples with cytological abnormality, HPV types were listed HPV-16, non-HPV 16-18, LR-HPV, HPV-18 and potential HR-HPV, respectively, in the samples that cytologi- cal abnormality was not found, HPV types were non-HPV-16-18, LR-HPV, HPV-16, HPV-18 and potential HR-HPV. Coclusion: Non-HPV-16-18 were monitored as the most common type and HPV-16 was third of frequency in cytological abnormality negative group; non-HPV-16-18 and HPV-16 were monitored close proportions of each other in cytological abnormality positive group. These isolates were accompany to preinvasive lesions.