Browsing by Author "Kurt, K"
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Item A new species of Zachaeus CL Koch from Turkey (Opiliones, Phalangiidae)Kurt, K; Koç, H; Yagmur, EAA new species of harvestmen, Zachaeus seyyari sp. n. (Opiliones, Phalangiidae), is described and illustrated on the basis of both sexes from Sirnak Province in Turkey. Differences between the new species and related species are indicated. Photographs of its characteristic structures are also provided.Item Mesenteric fibromatosis: A case reportAyhan, S; Temiz, P; Kurt, KItem DESCRIPTION OF THE UNKNOWN FEMALE OF THE HARVESTMAN RAFALSKIA AZIZSANCARI KURT, YAGMUR & TEZCAN, 2019 (ARACHNIDA: OPILIONES: PHALANGIIDAE) FROM TURKEYKurt, K; Yagmur, EA; Kurt, PThe female of Rafalskia azizsancari Kurt, Yagmur & Tezcan, 2019, previously known only from the male in Turkey, is now described based on new material from Odemis District, Izmir Province, Turkey. Detailed morphological descriptions, photographs and illustration of the female ovipositor are provided.Item REDESCRIPTION AND NEW RECORD OF THE HARVESTMAN LACINIUS INSULARIS ROEWER, 1923 (OPILIONES: PHALANGIIDAE) FROM TURKEYKurt, K; Yagmur, EALacinius insularis Roewer, 1923, is recorded for the first time as part of the Turkish harvestmen fauna. Prior to this, the species was only known from the island of Crete in Greece. The new collections were made on Nif mountain in Izmir Province (far western Turkey). In this study, L. insularis is redescribed based on adults from Turkey. Its detailed description, morphological characteristics, distribution and measurements are given. Also, genitalia, body dorsal view, chelicerae, and pedipalp are illustrated. In addition, this species is compared with similar species.Item Redescription of Buresilia macrina (Roewer, 1956) (Opiliones, Phalangiidae) from Turkey with the first description of the femaleKurt, K; Yagmur, EA; Kurt, PBuresilia macrina (Roewer, 1956) is redescribed and illustrated based on specimens collected from Adana Province, Turkey. The female is described herein for the first time.Item Rafaiskia azizsancari sp. n., a new harvestman (Opiliones: Phalangiidae) from TurkeyKurt, K; Yagmur, EA; Tezcan, EA new harvestman species, Rafaiskia azizsancari sp. n., is described and illustrated based on male specimens collected from Bozdaglar Mountains, Izmir Province, Turkey. Most important differences between the new species and the three other species of the genus are included.Item TWO NEW RECORDS FOR TURKISH HARVESTMEN FAUNA (ARACHNIDA: OPILIONES)Kurt, K; Koç, H; Yagmur, EATwo harvestmen species, Mediostoma haasi (Roewer, 1953) and Phalangium armatum Snegovaya, 2005, are recorded in Turkey for the first time. Their description, characteristic features, distributions, measurements and photographs of genitalia and general habitus of both sexes are presented.Item Mediostoma izmirica sp nov.: a new harvestman species (Arachnida, Opiliones, Nemastomatidae) from TurkeySnegovaya, NY; Kurt, K; Yagmur, EAA new harvestman species of the genus Mediostoma Kratochvil, 1958, Mediostoma izmirica sp. nov., is described and illustrated based on males and females from Izmir Province, Turkey. Differences between the new species and other species of the genus Mediostoma are indicated. Scanning electron microscope photographs of its characteristic structures are also given.Item A comparison of cancer stem cell markers and nonclassical major histocompatibility complex antigens in colorectal tumor and noncancerous tissuesÖzdemir, RBÖ; Özdemir, AT; Oltulu, F; Kurt, K; Yigittürk, G; Kirmaz, CColorectal carcinoma (CRC) is one of the most fatal types of cancer in both women and men, and, unfortunately, patients are often diagnosed at an advanced stage. Cancer stem cells (CSCs) are associated with poor prognosis, metastasis, and recurrence, as well as chemotherapy and radiotherapy resistance. Therefore, different treatment alternatives are needed to facilitate the elimination of CSCs. One such approach is immunotherapy; however, tumor cells can evade immune cells by alteration of the expression patterns of human leukocyte antigens (HLA). In this study, we immunohistochemically investigated the expression patterns of CSC-specific markers CD44, CD133, Nanog, and Oct3/4, and immunosuppressive molecules HLA-G and -E in advanced CRC tumor tissues and noncancerous colon biopsies. We found significantly increased CD44, Nanog, Oct3/4, HLA-G, and HLA-E expression in the CRC tumor tissues compared with the noncancerous colon biopsies. These findings suggest that some tumor cells may be CSC-like and that the increased expression of HLA-G and HLA-E may be considered as an immune-evasive adaptation. Therefore, the nonclassical major histocompatibility complex class Ib antigens HLA-G and HLA-E may be potential targets in the elimination of CRC-CSCs. However, more detailed studies are required to support our findings. (C) 2016 Elsevier Inc. All rights reserved.Item Characterization and some fundamental features of Optically Stimulated Luminescence measurements of silver activated lithium tetraborateOzdemir, A; Altunal, V; Guckan, V; Can, N; Kurt, K; Yegingil, I; Yegingil, ZA new lithium tetraborate (Li2B4O7 or abbreviated as LTB) material was produced by adding various concentrations of Ag impurities to allow better luminescent properties using the solution combustion synthesis (SCS) method. The formation of single phase LTB was confirmed using X-ray Diffraction (XRD) data and Scanning Electron Microscopy (SEM) analysis indicated the existence of a tetragonal crystalline domain. Two broad band emissions located at similar to 272 nm (near UV region) and 526 nm (green region) were observed from room temperature photoluminescence (PL) under 205 nm excitation The synthesized material consisted of polycrystalline LTB with 1 wt% Ag (abbreviated herein as LTB: Ag) exhibits considerable thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) which is several times more sensitive to beta radiation than the other concentrations attempted. It was determined that the OSL signal has been a collection of three component signals. A step-preheating procedure to investigate the depth of the trapping centers associated with the OSL signal was carried out. We suggest that the TL peak at 200 degrees C mainly contributes to the OSL signal. It was observed that the total OSL area shows a linear dose response for beta doses ranging from 1 to 100 Gy. The minimum detectable dose (MDD) value was found to be around 3 mGy using the total OSL area. Under optimum conditions (irradiation with beta-rays), the reproducibility of total OSL area was determined with a - 3% deviation at the end of the 9th irradiation-blue light stimulation-readout cycle. The dark storage stability of the total OSL signals was investigated and fading of the total OSL area was found to be approximately 25% after one week. The trap depth corresponding to the OSL signal was found to be 0.99 eV and 0.94 eV using various heating rate and isothermal annealing methods, respectively. Finally, silver doped lithium tetraborate is shown to have promise as an optically stimulated luminescent dosimeter, particularly in medical and personal applications.Item An immunoevasive mechanism for cancer stem cells: increased expressions of HLA-G and HLA-EÖzdemir, RBO; Özdemir, AT; Kirmaz, C; Oltulu, F; Yigittürk, G; Kurt, KItem The Expressions of Cancer Stem Cell Markers and Non-classical HLA antigens in Breast TumorsÖzdemir, RBÖ; Özdemir, AT; Oltulu, F; Kurt, K; Yigittürk, G; Kirmaz, CObjective: There is a strong relationship between the cancer stem cells (CSCs) and poor prognosis, metastasis and recurrence. In addition to this CSCs are resistant to chemotherapy and radiotherapy. Therefore, current treatment approaches may be ineffective to elimination of CSCs. The tumor cells have various adaptations for escaping from immune cells. The human leukocyte antigen (HLA)-G, which expressions restricted with fetal tissues and HLA-E are kind of tumor immune evasive adaptations. In this study, we aimed to investigate the relationship between the CSCs and immune evasive adaptations of breast tumors. Methods: We immunohistochemically evaluated that the expressions of cluster of differentiation (CD) 44, CD133, Homeobox protein Nanog, octamer-binding transcription factor (Oct) 3/4, HLA-G and HLA-E in the advanced stage breast cancer tissues (n= 10) and the non-malignant breast biopsies (n= 10). Results: We detected that the significantly increased expressions of especially Nanog (p< 0.001) and also CD44 (p< 0.001), CD133 (p< 0.001) and Oct3/4 (p< 0.001) in the advanced stage breast tumor group compared with non-malignant breast biopsies group, but the HLA-G (p< 0.001) and HLA-E (p< 0.001) decreased. Conclusion: These findings suggested that, malignant breast tumors may have CSC-like cells, and these cells may play role for occurring malignant behavior. To proliferation and tumor formation, the immune evasion is essential for both of malignant and benign tumors. Higher expressions of HLA-G and HLA-E may be an indication that the non-malign tumors more immune evasive than the malign tumors. However, further prospective studies are needed to confirm our findings.Item Optically Stimulated Luminescence (OSL) dosimetric properties of Li2B4O7:Ag,Gd and its relationship with thermoluminescence (TL) glow-curvesOzdemir, A; Can, N; Kurt, K; Yegingil, ZThe aim of this work was to develop a new lithium tetraborate luminophore with impurities that are strong co-activators for Optically Stimulated Luminescence (OSL) and to investigate its dosimetric properties using OSL method. Li2B4O7:Ag,Gd phosphor consisting of polycrystalline powder was synthesized using Solution Combustion Synthesis method. The structural characterization of the synthesized phosphor was performed using X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) methods. OSL dosimetry properties as a function of step-annealing procedure, radiation dose response, reproducibility of response and loss of stored signal in dark were investigated. Thermoluminescence (TL) glow curve of Li2B4O7:Ag,Gd phosphor consists of two separated glow peaks located at similar to 80 and similar to 210 degrees C with a heating rate of 2 degrees C/s. The traps responsible for these two TL peaks in Li2B4O7:Ag,Gd phosphor were found to be optically sensitive. Li2B4O7:Ag,Gd exhibits high OSL sensitivity and a good OSL signal reproducibility to ionizing radiation. The beta dose-response was performed in the range from 0.1 Gy to 500 Gy. The time-integrated total OSL signal intensity increases linearly with increasing dose from -6 Gy to 500 Gy. The minimum detectable dose was found to be -17.1 +/- 0.9 mu Gy. The stored energy increased -6 % within 4 weeks following a strong fading value of 27 % of the initial OSL intensity after 24 h. Indeed, the X-ray Luminescence (XL) emission spectra are the characteristic of the expected f-f transitions. Luminescence spectrum of Gd doped Li2B4O7 exhibits major red emissions (590 nm, 607 nm, 621 nm) and a weak blue emission (450 nm) along with the emission bands from undoped Li2B4O7. These results strongly suggest that the luminescence properties of Li2B4O7:Ag,Gd deserves more attention as possible dosimeter material. Explanations of many TL/OSL phenomena observed in the study of Li2B4O7:Ag,Gd phosphor and improvements based on the better knowledge in the mechanism of TL/OSL in Li2B4O7:Ag,Gd, a boron-based compound were achieved by this study. (C) 2018 Published by Elsevier B.V.Item Luminescence characterisation of defects in pld alumina and copper implanted silicaWu, Z; Türkler, A; Brooks, R; Hole, DE; Townsend, PD; Köster, SF; Kurt, K; Gonzalo, J; Suarez-Garcia, ALuminescence is reported for alumina and Al2O3:Cu films grown by pulsed laser deposition and is contrasted with luminescence from Cu ion implanted silica. The implanted samples display numerous emission bands with at least two associated to charge states or the Cu ions. The relative band intensities are altered by thermal treatments. In the case of the thin films the signals are sensitive to the growth conditions and show evidence for trapped Ar nanoparticles, from argon used as a background gas during film growth. Thus in both thin film and ion implanted material the luminescence offers a route to monitor the state of the defects and the copper impurity ions. (C) 2002 Published by Elsevier Science B.V.