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Effects of polycyclic aromatic hydrocarbon-containing oil mixtures on generation of reactive oxygen species and cell viability in MCF-7 breast cancer cells

B. Yılmaz | J. Ssempebwa | C.R. Mackerer | K.F. Arcaro | D.O. Carpenter

Article | 2007 | Journal of Toxicology and Environmental Health - Part A: Current Issues70 ( 13 ) , pp.1108 - 1115

Clarified slurry oil (CSO), and two crude oil samples, Belridge heavy crude oil (BHCO) and Lost Hills light crude oil (LHLCO), were examined for their ability to generate reactive oxygen species (ROS) in MCF-7 cells. Intracellular ROS and cell viability were determined in a flow cytometer using dihydroxyrhodamine 123 and propidium iodide, respectively. In experiments with short-term exposure, single-cell suspensions were loaded with the fluorescent probes and then treated with the oil samples (1 or 10 ppm). Measurements were made at 5, 15, 30, 60, and 90 min after addition of oil samples. In experiments with longer term exposure, pr . . .econfluent cell cultures were treated with oil samples for 6, 12, or 24 h prior to preparing single-cell suspensions. Both short-term and longer term treatment with oil samples resulted in elevated generation of reactive oxygen species (ROS). Cell cultures also were treated with benzo[a]pyrene, a polycyclic aromatic hydrocarbon detected in all three oil samples. Treatment with benzo[a]pyrene produced a significant increase in levels of ROS. The present findings suggest that oil samples with higher concentrations of polycyclic aromatic hydrocarbons may exert adverse effects on human mammary epithelial tissue through induction of oxidative stress. Copyright © Taylor & Francis Group, LLC Daha fazlası Daha az

The effect of N G -nitro L-arginine methyl ester on colonic anastomosis after increased intra-abdominal pressure

C. Polat | Y. Arıkan | C. Gokce | F. Aktepe | G. Akbulut | S. Yilmaz | O. Gokce

Article | 2007 | Langenbeck's Archives of Surgery392 ( 2 ) , pp.197 - 202

Background: Intestinal ischemia-reperfusion (I/R) is associated with augmented nitric oxide (NO) production. Increased intra-abdominal pressure (IAP) during surgical pneumoperitoneum (P) facilitates I/R injury. We previously demonstrated decreased strength and healing of colocolic anastomoses after high IAPs. The effect of an NO synthase inhibitor, N G -nitro-arginine methyl ester (l-NAME), on anastomoses realized in colonic tissue exposed to high IAPs was investigated in this study, a randomized, controlled, and experimental study with blind outcome assessment. Method: Fifty Wistar-albino rats were randomized to five groups; all un . . .derwent colocolic anastomosis. P was maintained for 60 min at IAPs of 14, 20, 25, and 30 mmHg in study groups 1, 2, 3, and 4, respectively; P was preceded by intraperitoneal l-NAME (2.5 mg/kg) and followed by anastomosis. The control group was not subjected to IAP or l-NAME. Results: Anastomosis bursting pressure (ABP) values and histopathological findings were determined on the 7th-14th postoperative days. The ABPs of groups 3-4 were significantly lower than the others. Groups 1-2 had results similar to controls. Histopathological findings of the groups were consistent with their ABPs. Conclusion: Administration of a 2.5-mg/kg intraperitoneal l-NAME dose was found to provide a beneficial role, implying a role in impaired anastomotic healing after IAPs of 14 and 20 mmHg. © 2006 Springer-Verlag Daha fazlası Daha az

Residential electricity demand dynamics in Turkey

F. Halicioglu

Article | 2007 | Energy Economics29 ( 2 ) , pp.199 - 210

This article provides fresh empirical evidences for the income and price elasticies of the residential energy demand both in the short-run and long-run for Turkey over the period 1968-2005, using the bounds testing procedure to cointegration. The computed elasticities of income and price are consistent with the previous studies and, as expected, the long-run elasticities are greater than the short-run elasticities. An augmented form of Granger causality analysis is implemented among residential electricity, income, price and urbanization. In the long-run, causality runs interactively through the error-correction term from income, pr . . .ice and urbanization to residential energy but the short-run causality tests are inconclusive The parameter stability of the short-run as well as long-run coefficients in the residential energy demand function are tested. The results of these tests display a stable pattern. © 2006 Elsevier B.V. All rights reserved Daha fazlası Daha az

Linearization of one-dimensional nonautonomous jump-diffusion stochastic differential equations

G. Ünal | I. Iyigünler | C.M. Khalique

Article | 2007 | Journal of Nonlinear Mathematical Physics14 ( 3 ) , pp.430 - 442

Necessary and sufficient conditions for the linearization of one-dimensional nonautonomous jump-diffusion stochastic differential equations are given. Stochastic integrating factor is introduced to solve the linear jump-diffusion stochastic differential equations. Closed form solutions to certain linearizable jump-diffusion stochastic differential equations are obtained.

Erosive and buffering capacities of yogurt

Kargul, B. | Caglar, E. | Lussi, A.

Article | 2007 | Quintessence International38 ( 5 ) , pp.381 - 385

Objective: The capability of drinks and foods to resist pH changes brought about by salivary buffering may play an important role in the erosion of dental enamel. The aim of the present study was to measure the initial pH of several types of yogurt and to test the degrees of saturation (pK-pl) with respect to hydroxyapatite and fluorapatite to determine the buffering capacity and related erosive potential of yogurt. Method and Materials: Twenty-five milliliters of 7 types of freshly opened yogurt was titrated with 1 mol/L of sodium hydroxide, added in 0.5 mL increments, until the pH reached 10, to assess the total titratable acidity . . ., a measure of the drink's own buffering capacity. The degrees of saturation (pK-pl) with respect to hydroxyapatite and fluorapatite were also calculated, using a computer program developed for this purpose. For statistical analysis, samples were compared using Kruskal-Wallis test. Results: The buffering capacities can be ordered as follows: fruit yogurt > low-fat yogurt > bioyogurt > butter yogurt > natural yogurt > light fruit yogurt > light yogurt. The results suggest that, in vitro, fruit yogurt has the greatest buffering capacity. Conclusion: It can be stated that it is not possible to induce erosion on enamel with any type of yogurt Daha fazlası Daha az

An alternative treatment approach to gingival recession: gingiva-colored partial porcelain veneers: A clinical report

Capa, N.

Article | 2007 | Journal of Prosthetic Dentistry98 ( 2 ) , pp.82 - 84

This clinical report describes the treatment of excessive gingival recession involving maxillary right and left central incisors in a 30-year-old woman. The loss of the gingival soft tissue caused an increase in crown length. Gingiva-colored partial porcelain laminate veneers were applied to imitate the lost gingiva and to provide a natural anatomical tooth length. This method may be a minimally invasive alternative treatment method for gingival soft tissue loss, providing esthetic results and patient satisfaction. © 2007 The Editorial Council of the Journal of Prosthetic Dentistry.

Formation of calcium phosphate whiskers in hydrogen peroxide (H2O2) solutions at 90°C

Tas, A.C.

Article | 2007 | Journal of the American Ceramic Society90 ( 8 ) , pp.2358 - 2362

A novel, one-pot technique of synthesizing calcium phosphate whiskers was developed. Commercially available ß-tricalcium phosphate (ß-Ca3(PO4)2) powders were aged in unstirred 30% H2O2 solutions at 90°C for 48 h in ordinary glass media bottles. Resultant samples consisted of whiskers (200 nm wide and 5 µm-long) of a biphasic mixture of octacalcium phosphate (OCP: Ca8H2(PO4)6·5H2O) and carbonated apatitic (apatite-like) calcium phosphate (Ap-CaP). As-formed whiskers possessed a Ca/P molar ratio of 1.46 and a BET surface area of 8 m2/g. Upon soaking these whiskers in a Tris-HCl-buffered SBF solution of 27 mM HCO3- for 6 days, Ca/P mol . . .ar ratio and surface area values were increased to 1.60 and 52 m2/g, respectively. The technique, owing to its simplicity, may prove useful in providing large amounts of biocompatible short whiskers for numerous technology sectors. © 2007 The American Ceramic Society Daha fazlası Daha az

Chondroid syringoma of the hand: A rare localization

Bekler, H. | Gokce, A. | Beyzadeoglu, T.

Article | 2007 | Handchirurgie Mikrochirurgie Plastische Chirurgie39 ( 6 ) , pp.430 - 432

Chondroid syringoma is a rare benign neoplasm of the sweat glands that usually occurs in the head and neck region. We describe a 18-year-old male patient with a benign chondroid syringoma that occurred at an unusual site, leading to compression symptoms of the ulnar nerve causing symptoms at the hypothenar region of the right hand. Although it is a rare tumor at an unusual site, it should be included in the differential diagnosis of the hand tumors. © Georg Thieme Verlag KG Stuttgart.

An unusual cause of atrial fibrillation: Exposure to insecticides

Topacoglu, H. | Unverir, P. | Erbil, B. | Sarikaya, S.

Article | 2007 | American Journal of Industrial Medicine50 ( 1 ) , pp.48 - 49

Background: Although there are many well-known cardiac results of insecticide poisoning, atrial fibrillation (AF) has not been reported as the result of insecticide intoxication. Case: Twenty-six-year-old male, complaining of nausea and vomiting, presented to the emergency department with a history of methomyl dust exposure. All physical examination findings were normal except irregular heart rate on cardiac auscultation. The electrocardiogram of the patient showed AF with normal ventricular response. Patient's acetylcholinesterase (ACE) level was 3,319 IU/L in presentation and pralidoxim use was seen unnecessary for the treatment. . . .The patient's rhythm spontaneously returned to sinus rhythm 24 hr after the presentation and no cardiopulmonary pathology was found during the follow-up. The patient was discharged without symptoms. Conclusion: AF is a rare complication of insecticide intoxication. In this case, treatment of symptoms was adequate until a normal sinus rhythm returned. © 2006 Wiley-Liss, Inc Daha fazlası Daha az

Compressive strength, surface roughness, fluoride release and recharge of four new fluoride-releasing fissure sealants

Cildir, S.K. | Sandalli, N.

Article | 2007 | Dental Materials Journal26 ( 3 ) , pp.335 - 341

The aim of this study was to investigate the compressive strength and surface roughness of two glass ionomer cements and two resin-based fissure sealants before and after fluoride release and recharge. Twenty-one specimens were prepared and divided into three groups for each material. First group was loaded in compression until failure. Fluoride released was measured from the remaining specimens, and then the second group of seven specimens was loaded at 28th day. The remaining seven specimens were exposed to 0.05% NaF solution and 1.23% APF gel. Fluoride amount was measured, and the last group was loaded at 70th day. Surface roughn . . .ess measurement of five more disk-shaped specimens from each material was also carried out. After exposure to APF gel, all materials were recharged. At the end of experimental period, it was found that surface roughness increased, whereas compressive strength decreased, over time. In conclusion, fluoride-releasing fissure sealants could act as show, rechargeable fluoride release systems. However, if a fissure sealant exhibited high fluoride release, it had inferior mechanical properties Daha fazlası Daha az

Complicated flap creation with femtosecond laser after radial keratotomy

Perente, I. | Utine, C.A. | Cakir, H. | Yilmaz, O.F.

Article | 2007 | Cornea26 ( 9 ) , pp.1138 - 1140

PURPOSE: To report a case of laser in situ keratomileusis (LASIK) that used the Intralase femtosecond laser 14 years after radial keratotomy (RK) for residual myopic astigmatism. METHODS: A 39 year-old male patient had undergone a bilateral RK operation for myopic correction. The manifest refraction was -1.25 -3.00 × 175 D, with uncorrected visual acuity (UCVA) of 20/50 and best-corrected visual acuity (BCVA) of 20/20. The central and thinnest pachymetry measurements were 582 and 576 µm, respectively, by Orbscan II. RESULTS: Intralase was used for LASIK, and initially, a loss of suction was seen during flap formation. The flap could . . . be created again at the same intracorneal plane. During flap lifting, the RK incisions were separated, and one of the RK incisions progressed to the corneal center with the force applied by the blunt spatula. No piece was separated completely from the flap. Excimer laser treatment and flap repositioning could be done without any problems. At the fifth postoperative month, his UCVA was 20/20. All RK incisions seemed well aligned. There was no haze or epithelial ingrowth. CONCLUSIONS: This case showed that the Intralase femtosecond laser not only has no unique benefit as opposed to the mechanical keratome for post-RK eyes but also can lead to serious complications. We recommend that femtosecond laser flap formation not be used in post-RK eyes. © 2007 Lippincott Williams & Wilkins, Inc Daha fazlası Daha az

Decoupling refractive index and geometric thickness from interferometric measurements of a quartz sample using a fourth-order polynomial

Ince, R. | Hüseyinoglu, E.

Article | 2007 | Applied Optics46 ( 17 ) , pp.3498 - 3503

A Michelson interferometer setup was used to determine refractive index and thickness of a fused-quartz sample with no knowledge of either parameter. At small angles, <10°, the interferometer equation follows a fourth-order polynomial in the sample refractive index alone, effectively decoupling the sample thickness from the equation. The incident angle of the He-Ne laser beam versus fringe shift was fitted to the polynomial, and its coefficients obtained. These were used to determine refractive index to within 6 × 10 -4 of the known value with an accuracy of ± 1.3%. Sample thickness was determined to an accuracy of ± 2.5%. Reprod . . .ucibility of the rotating table was determined to be ±2 × 10-3 degrees. © 2007 Optical Society of America Daha fazlası Daha az

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