The Effect of Urethral Catheterisation on Serum Prostate-Specific Antigen Levels in Male Patients with Acute Urinary Retention

Kubilay Erdogan,Mesut Gurdal,Ali Tekin, Sinan Kirecci,Feridun Sengor 연세대학교의과대학 2003 Yonsei medical journal Vol.44 No.4

Urethral catheterisation is often used in acute urinary retention (AUR). In this study, we aimed to evaluate the effect of urethral catheterisation on serum prostate-specific antigen (PSA) levels in men with AUR. Our study subjects comprised 35 men with a mean age of 63.7±7.35 years (range 55-80) who presented with AUR at our department between March 1999 and June 2000. Patients were randomly divided into two groups; 18 patientsunderwent urethral catheterisation in the first group (catheterisation group), while 17 underwent suprapubic percutaneous cystostomy in the second group (cystostomy group). Serum PSA levels before manipulation, and 2 and 12 hours and 7 days after treatment were determined. The change in median PSA values after manipulation was statistically significant in the catheterisation group (p<0.05), but not in the cystostomy group (p>0.05). The change in serum PSA was not clinically important in any of the patients. These results suggested that urethral catheterisation did not cause a significant alteration in serum PSA in men with AUR retention.

Investigation of Hydration Temperature of Alkali Activated Slag Based Concrete

Kubilay Akçaözoğlu,Semiha Akçaözoğlu,Abdullah Açıkgöz 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.8

This paper presents the results of an investigation on the effect of activator type, binder amount and sodium dosage on hydrationheats of Alkali-Activated Slag (AAS) concrete. For the slag activation, sodium hydroxide (NaOH) pellets and the mixture ofNaOH+liquid sodium silicate (Na2SiO3) were used at three sodium concentrations, 4%, 6% and 8% by mass of slag. Twenty onedifferent mixtures were prepared for the laboratory tests. In the reference three mixtures, OPC was used as binder and in the otherAAS mixtures Granulated Blast Furnace Slag (GBFS) was used. The binder dosages were 300, 350 and 400 kg/m3 and the waterbinder(w/b) ratio used in the mixtures was 0.50. The compressive strength and hydration temperature of produced concretes weremeasured. The temperature change of specimens measured in every 15 minutes until 120 hours. The test results showed that, thecompressive strengths and hydration temperatures of the mixtures increased depending on increasing binder amount and sodiumdosage. The use of NaOH+Na2SiO3 mixture as activator increased compressive strength but decreased hydration temperature of themixtures. The hydration temperatures of all AAS mixtures were lower than OPC mixtures. Produced AAS concrete with lowhydration temperature can be an alternative in recycled construction material at mass concrete applications.

Preform-Based Production of Al2O3-Reinforced Aluminium Matrix Composites by Using Various Modification Techniques

Kubilay Ozturk,Ridvan Gecu,Ahmet Karaaslan 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.5

Metal matrix composites have a wide range of applications due to their lightweight, high strength and high wear resistance.In this study, Al2O3-reinforced AA7075 matrix composites were produced by using liquid metal infiltration method in twostages. In the first stage of the production, preforms were manufactured by using Al2O3particles and different binders. Someof the preforms were sintered and some were not sintered. In the second step, liquid metal infiltration was performed on bothsintered and not sintered samples. Some preforms were preheated before the infiltration and some were directly subjected tothe liquid metal infiltration. The casting process was carried out in two different ways: (1) pouring the molten metal into thefired mould and (2) in situ melting of the metal during the mould firing. Fabricated composites were characterized by XRD,light metal microscopy, SEM, EDS, Brinell hardness and ball-on-disc type wear tests. When the microstructural, mechanicaland tribological properties were taken into account, preheating and sintering preforms before casting were determinedas performing best with the hardness of ~ 150 HB and the wear rate of 1.1 × 10−4 mm3/(N m), whereas the in situ meltingcaused decrease in the mechanical strength and wear resistance because of excessive oxidation.

Numerical Plane-Strain Modelling of Stone Columns: Installation Process, Single and Group Column Behaviour

M. Kubilay Kelesoglu,Caner Durmus 대한토목학회 2022 KSCE Journal of Civil Engineering Vol.26 No.8

The scope of this paper is to emphasize the critical issues related to the axisymmetric and plane-strain modelling of single and group of stone columns constructed to stabilise soft soils. A simple technique based on the expansion of the column shaft was used to simulate the column installation so that the excess pore pressures during this process were calculated for a single column under axisymmetric conditions. Classical cavity expansion theory was also used for the same purpose. The group behaviour of stone columns was discussed by two-dimensional plane–strain numerical models. Plane-strain modelling of stone columns should consider the conversion of stiffness and the drainage properties of the columns and the soft soils to the plane-strain conditions. The validity of two different conversion methods based on the equivalent plane-strain stiffness and equivalent plane-strain permeability coupled with the expansion of the column shaft technique were investigated. An existing well-documented centrifuge test data were used as a reference for numerical models of axisymmetric single column and plane-strain column groups. The measured and calculated results were in good agreement for the case where the finite element model was constituted based on the equivalent plane-strain permeability. The results of this study intend to bring insight to the plane-strain modelling of a group of stone columns.

The effect of thickness and translucency of polymer-infiltrated ceramic-network material on degree of conversion of resin cements

Barutcigil, Kubilay,Buyukkaplan, Ulviye Sebnem The Korean Academy of Prosthodonitics 2020 The Journal of Advanced Prosthodontics Vol.12 No.2

PURPOSE. The aim of the present study was to determine the degree of conversion of light- and dual-cured resin cements used in the cementation of all-ceramic restorations under different thicknesses of translucent (T) and high-translucent (HT) polymer-infiltrated ceramic-network (PICN) material. MATERIALS AND METHODS. T and HT PICN blocks were prepared at 0.5, 1.0, 1.5, and 2.0 mm thicknesses (n=80). Resin cement samples were prepared with a diameter of 6 mm and a thickness of 100 ㎛. Light-cured resin cement was polymerized for 30 seconds, and dual-cure resin cement was polymerized for 20 seconds (n=180). Fourier transform infrared spectroscopy (FTIR) was used for degree of conversion measurements. The obtained data were analyzed with ANOVA and Tukey HSD, and independent t-test. RESULTS. As a result of FTIR analysis, the degree of conversion of the light-cured resin cement prepared under 1.5- and 2.0-mm-thick T and HT ceramics was found to be lower than that of the control group. Regarding the degree of conversion of the dual-cured resin cement group, there was no significant difference from the control group. CONCLUSION. Within the limitation of present study, it can be concluded that using of dual cure resin cement can be suggested for cementation of PICN material, especially for thicknesses of 1.5 mm and above.

Ballistic impact response of Kevlar Composites with filled epoxy matrix

Yeliz Pekbey,Kubilay Aslantaş,Nihal Yumak 국제구조공학회 2017 Steel and Composite Structures, An International J Vol.24 No.2

Impact resistance and weight are important features for ballistic materials. Kevlar fibres are the most widely reinforcement for military and civil systems due to its excellent impact resistance and high strength-to-weight ratio. Kevlar fibres or spectra fiber composites are used for designing personal body armour to avoid perforation. In this study, the ballistic impact behaviour of Kevlar/filled epoxy matrix is investigated. Three different fillers, nanoclay, nanocalcite and nanocarbon, were used in order to increase the ballistic impact performance of Kevlar-epoxy composite at lower weight. The filler, nanoclay and nanocalcite, content employed was 1 wt.% and 2 of the epoxy resin–hardener mixture while the nanocarbon were dispersed into the epoxy system in a 0.5%, 1% and 2% ratio in weight relating to the epoxy matrix. Specimens were produced by a hand lay-up process. The results obtained from ballistic impact experiments were discussed in terms of damage and perforation. The experimental tests revealed a number of damage mechanisms for composite laminated plates. In the ballistic impact test, it was observed whether the target was perforated completely penetrated at the back or not. The presence of small amounts of nanoclay and nanocalcite dispersed into the epoxy system improved the impact properties of the Kevlar/epoxy composites. The laminates manufactured with epoxy resin filled by 1 wt.% of nanoclay and 2 wt% nanocalcite showed the best performance in terms of ballistic performance. The addition of nanocarbon reduced ballistic performance of Kevlar-epoxy composites when compared the results obtained for laminates with 0% nanoparticles concentration.

The role of C-reactive protein ratio in predicting mortality in patients with Fournier gangrene

Eray Ismail Cem,Dalci Kubilay,Gumus Serdar,Yalav Orcun,Saritas Ahmet Gokhan,Boz Asli,Rencuzogullari Ahmet 대한대장항문학회 2023 Annals of Coloproctolgy Vol.39 No.3

Purpose: This study aimed to determine the C-reactive protein (CRP) ratio for the survival of patients with Fournier gangrene (FG). Methods: Fifty-two patients with FG between January 2011 and September 2018 were retrospectively analyzed. Data on clinical presentation, Fournier Gangrene Severity Index (FGSI), CRP ratio, management, and outcome were analyzed. The CRP ratio was calculated as preoperative CRP/postoperative CRP value that measured 48 hours after surgical intervention. Possible alternative cutoff points for the FGSI and CRP were determined by receiver operating characteristic (ROC) analyses. The risk factors related to the prognosis were evaluated by univariate and multivariable logistic regression analyses. Results: The mean CRP ratios were 6.7±6.6 in the survivor group and 1.2±0.8 in the nonsurvivor group (P=0.001). FGSI was significantly higher in the non-survivor group compared to survivor group (8.5±2.5 vs. 3.5±2.2, P=0.001). There was a negative correlation between FGSI and CRP ratio (r=–0.51). ROC analysis determined the cutoff value as 1.78 for CRP (sensitivity, 86%; specificity, 82%; area under the ROC curve, 0.90) to predict death. The incidence of death for patients with CRP ratio of ≤1.78 increased 26.7 fold for those with CRP ratio of >1.78 (95% confidence interval [CI], 4.8–146.5; P=0.001). In the multivariable logistic regression model, CRP ratio (odds ratio [OR], 10.3; 95% CI, 1.5–72.2; P=0.019) and FGSI (OR, 17.8; 95% CI, 2.6–121.1; P=0.003) were independent risk factors for death. Conclusion: The CRP ratio is a simple method to use to predict mortality in FG.

Purification and Characterization of an Alkali-Thermostable Lipase from Thermophilic Anoxybacillus flavithermus HBB 134

( Zehra Burcu Bakir ),( Kubilay Metin ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.6

An intracellular lipase from Anoxybacillus flavithermus HBB 134 was purified to 7.4-fold. The molecular mass of the enzyme was found to be about 64 kDa. The maximum activity of the enzyme was at pH 9.0 and 50oC. The enzyme was stable between pH 6.0 and 11.0 at 25°C, 40°C, and 50°C for 24 h. The Km and Vmax of the enzyme for pNPL substrate were determined as 0.084 mM and 500 U/mg, respectively. Glycerol, sorbitol, and mannitol enhanced the enzyme thermostability. The enzyme was found to be highly stable against acetone, ethyl acetate, and diethyl ether. The presence of PMSF, NBS, DTT and β-mercaptoethanol inhibited the enzyme activity. Hg(2+), Fe(3+), Pb(2+), Al(3+), and Zn(2+) strongly inhibited the enzyme whereas Li(+), Na(+), K(+), and NH4(+) slightly activated it. At least 60% of the enzyme activity and stability were retained against sodium deoxycholate, sodium taurocholate, n-octyl-β-D-glucopyranoside, and CHAPS. The presence of 1% Triton X-100 caused about 34% increase in the enzyme activity. The enzyme is thought to be a true lipase since it has preferred the long-chain triacylglycerols. The lipase of HBB 134 cleaved triolein at the 1- or 3-position.

The Early Histological Effects of Intravesical Instillation of Platelet- Rich Plasma in Cystitis Models

M. İrfan Dönmez,Kubilay İnci,Naciye Dilara Zeybek,H. Serkan Doğan,Ali Ergen 대한배뇨장애요실금학회 2016 International Neurourology Journal Vol.20 No.3

Purpose: To evaluate the early histological effects of the intravesical instillation of platelet-rich plasma (PRP) in rabbit models of interstitial and hemorrhagic cystitis. Methods: Thirty-six rabbits were classified into 6 groups: saline (S), S+PRP, hydrochloric acid (HCl), HCl+PRP, cyclophosphamide (CyP), and CyP+PRP. At 48 hours after induction, PRP was prepared and intravesically administered to the S+PRP, HCl+PRP, and CyP+PRP groups. Bladder sections were stained with toluidine blue for mast cell counting and with hematoxylin and eosin for histopathology and mitotic index determination. The proliferation index was determined by proliferating cell nuclear antigen (PCNA) immunolabeling. The nonparametric Mann-Whitney U-test was used for statistical analysis. Results: No abnormalities were observed in the S group, whereas increased interstitial edema and increased average mitotic and proliferation indices were observed in the S+PRP group (P=0.023, P=0.004, and P=0.009, respectively). Intense epithelial loss, hemorrhage, and leukocyte infiltration were detected in the HCl and HCl+PRP groups, whereas a significantly increased average mitotic index was observed in the HCl+PRP group (P=0.002). When compared with its CyP counterpart, a significant reduction in hemorrhage and an increase in leukocyte infiltration and mitotic index were observed in the CyP+PRP group (P=0.006, P=0.038, and P=0.002, respectively). In addition, PCNA staining revealed a significantly increased proliferation index in the HCl+PRP and CyP+PRP groups (P=0.032 and P=0.015, respectively). Conclusions: The intravesical instillation of PRP increased the mitotic index in the saline and cyclophosphamide groups while decreasing macroscopic bleeding.

The usefulness of drainage-internal capitonnage with/ without selective bile duct repair technique for liver hydatid cyst

Atılgan Tolga Akcam,Ahmet Gokhan Saritas,Kubilay Dalcı,Abdullah Ulku 대한외과학회 2021 Annals of Surgical Treatment and Research(ASRT) Vol.100 No.5

Purpose: The aim of the present study is to describe the cavity-reducing internal capitonnage technique that we used for the surgical therapy of liver hydatid cyst, and contribute to the literature by presenting the short- and long-term outcomes of the patients who were operated on with this technique. Methods: A drainage and internal capitonnage technique was performed on 12 cases due to liver hydatid cyst in our clinic between January 2016 and December 2019. Results: The mean age of cases was 36.25 ± 12.5 years, with 7 females and 5 males. All cases had pain in the right upper quadrant, and a sense of fullness in 5 cases. None of the cases had ruptured cysts, jaundice, or other clinical manifestations. The preoperative laboratory findings were normal in 8 cases. Intraoperative biliary-cyst communication was demonstrated in 8 cases (66.7%). Cases were followed up for a mean duration of 38.1 months (range, 24–88 months). Conclusion: The drainage/internal capitonnage with/without selective bile duct repair is a technique that can be performed with very low morbidity and mortality rates in experienced hands, especially for centrally located hydatid cysts.