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Synthesis, characterization and radioluminescence properties of erbium-doped yttria phosphors

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International Journal of Minerals,Metallurgy and Materials 2021年第12期28卷 1983-1990页

作者： Fatma Unal Faruk Kaya kursat Kazmanli Metallurgical and Materials Engineering Department Hitit UniversityCorum 19030Turkey Metallurgical and Materials Engineering Department Istanbul Technical UniversityMaslakIstanbul 34469Turkey

radioluminescence(rL)behaviour of erbium-doped yttria nanoparticles(Y2O_(3):Er^(3+)NPs)which were produced by sol-gel method was reported for future scintillator *** with dopant rates of 1 at%,5 at%,10 at%and 20 at%Er were produced and calcined at 800℃,and effect of increased calcination temperature(1100℃)on the rL behaviour was also reported.X-ray diffraction(XrD)results showed that all phosphors had the cubic Y2O_(3) bixbyite-type *** lattice parameters,crystallite sizes(CS),and lattice strain values were calculated by Cohen-Wagner(C-W)and Williamson-Hall(W-H)methods,***,the optimum solubility value of the Er^(3+)dopant ion in the Y2O_(3) host lattice was calculated to be approximately 4 at%according to Vegard’s law,which was experimentally obtained from the 5 at%Er^(3+)ion containing *** peak shifts in XrD patterns and X-ray photoelectron spectroscopy(XPS)analyses confirmed that Er^(3+)dopant ions were successfully incorporated into the Y2O_(3) host ***-resolution transmission electron microscopy(HrTEM)results verified the average CS values and agglomerated NPs morphologies were *** electron microscopy(SEM)results showed the neck formation between the particles due to increased calcination *** a result of the rL measurements under a Cu KαX-ray radiation(wavelength,λ=0.154 nm)source with 50 kV and 10 mA beam current,it was determined that the highest rL emission belonged to 5 at%Er doped *** the rL emission spectrum,the emission peaks were observed in the wavelength ranges of 510-575 nm(2H11/2,4S3/2-4I15/2;green emission)and 645-690 nm(4F9/2-4I15/2;red emission).The emission peaks at 581,583,587,593,601,611 and 632 nm wavelengths were also *** was found that both dopant rate and calcination temperature affected the rL emission *** color shifted from red to green with increasing calcination temperature which was attributed to the increased crystallinit

关键词： structure. temperature. solution.

Musical Isomorphisms and Problems of Lifts

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Chinese Annals of Mathematics,Series B 2016年第3期37卷 323-330页

作者： rabia CAKAN kursat AKBULUT Arif SALIMOV Department of Mathematics Ataturk University Azerbaijan National Academy of Sciences Institute of Mathematics and Mechanics

Using the complete lift on tangent bundles, the authors construct the complete lift on cotangent bundles of tensor fields with the aid of a musical isomorphism. In this new framework, the authors have a new intrepreta... 详细信息

关键词： Tensor fields Cotangent bundles Complete lift Anti-Hermitian metric riemannian extension

Soft ground tunnel lithology classification using clustering-guided light gradient boosting machine

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Journal of rock Mechanics and Geotechnical Engineering 2023年第11期15卷 2857-2867页

作者： kursat Kilic Hajime Ikeda Tsuyoshi Adachi Youhei Kawamura Department of Geosciences Geotechnology and Materials Engineering for ResourcesGraduate School of International Resource SciencesAkita UniversityAkita010-8502Japan Division of Sustainable resources Engineering Faculty of EngineeringHokkaido UniversityKita 13Nishi 8Kita-kuSapporo060-8628Japan

During tunnel boring machine(TBM)excavation,lithology identification is an important issue to understand tunnelling performance and avoid time-consuming ***,site investigation generally lacks ground samples and the information is subjective,heterogeneous,and imbalanced due to mixed ground *** this study,an unsupervised(K-means)and synthetic minority oversampling technique(SMOTE)-guided light-gradient boosting machine(LightGBM)classifier is proposed to identify the soft ground tunnel classification and determine the imbalanced issue of tunnelling *** the tunnel excavation,an earth pressure balance(EPB)TBM recorded 18 different operational parameters along with the three main tunnel *** proposed model is applied using Python low-code PyCaret ***,four decision tree-based classifiers were obtained in a short time period with automatic hyperparameter tuning to determine the best model for clustering-guided SMOTE *** addition,the Shapley additive explanation(SHAP)was implemented to avoid the model black box *** proposed model was evaluated using different metrics such as accuracy,F1 score,precision,recall,and receiver operating characteristics(rOC)curve to obtain a reasonable outcome for the minority *** shows that the proposed model can provide significant tunnel lithology identification based on the operational parameters of *** proposed method can be applied to heterogeneous tunnel formations with several TBM operational parameters to describe the tunnel lithologies for efficient tunnelling.

关键词： Earth pressure balance(EPB) Tunnel boring machine(TBM) Soft ground tunnelling Tunnel lithology Operational parameters Synthetic minority oversampling technique (SMOTE) K-means clustering

Some remarks Concerning Hyperholomorphic B-Manifolds

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Chinese Annals of Mathematics,Series B 2008年第6期29卷 631-640页

作者： Arif SALIMOV Murat ISCAN kursat AKBULUT Department of Geometry Baku State University Department of Mathematics Faculty of Arts and Sciences Ataturk University Department of Mathematics Faculty of Arts and SciencesAtaturk University

The authors consider a differentiable manifold with H-structure which is an isomorphic representation of an associative, commutative and unitial algebra. For riemannian metric tensor fields, the φ-operators associated with r-regular H-structure are introduced. With the help of φ-operators, the hyperholomorphity condition of B-manifolds is established.

关键词： Pure tensor field Interior product Holomorphic tensor B-Manifold

Assessment of thiol/disulfide homeostasis for prognostic follow-up of cholangiocarcinoma patients

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Cancer Advances 2023年第9期6卷 1-8页

作者： Zozan Guleken Huri Bulut kursat rahmi serin Melek Buyuk Engin Ulukaya Department of Physiology Faculty of MedicineGaziantep Islam Science and Technology UniversityKucukkızılhisar 27220GaziantepTurkey Department of Medical Biochemistry Faculty of MedicineIstinye UniversityIstanbul 34010Turkey Department of General Surgery Hepato-pancreato-biliary Surgery Unit Faculty of MedicineIstanbul UniversityIstanbul 34390Turkey Department of Pathology Faculty of MedicineIstanbul UniversityIstanbul 34390Turkey Molecular Cancer research Center(ISUMKAM) Istinye UniversityIstanbul 34010Turkey

Background:Cholangiocarcinoma(CCA)is a cancer type that builds in the bile ducts that carry digestive fluid,*** ducts connect the liver to the gallbladder and the small *** disease is often diagnosed at an advanced stage,resulting in a low 5-year survival *** study aims to evaluate the concentrations of serum thiol/disulfide in CCA patients and healthy volunteers and investigate the association between oxidative activity and clinical and pathological characteristics in CCA *** examining the relationship between reduced thiol/disulfide measures and tumorigenesis of the disease,we can potentially identify an unfavourable prognosis in CCA ***:To assess the status of thiol/disulfide in the blood of Cholangiocarcinoma patients using a novel automated homeostasis assay,we recruited 55 individuals for this study(CCA patients,n=27;healthy volunteers,n=28).We measured the levels of serum total thiol(TT)(–SH+–S-S–),native thiol(NT)(–SH),and disulfide(DD)(–S-S–)in both the CCA group and the control ***,we calculated the ratio of thiol/disulfide(–SH/–S-S–).results:We explored the relationship between oxidative activity and clinical and pathological characteristics in CCA *** study found no significant differences in age and sex between CCA patients and *** and TT levels were higher in the control group compared to the CCA ***,the disulfide level did not significantly differ between the two ***'s correlation matrix analysis revealed positive correlations between TT and NT levels and negative correlations between NT/TT%,DD level,and DD/TT%.Conclusion:Our findings suggest a statistical difference in serum thiol/disulfide *** a marker of total oxidant status,thiol and disulfide levels have decreased in patients with ***,no correlation was found between the tumour markers CEA and CA19-9 and thiol levels.A decrease in blood thiol and disulfide concentrations or the ratio

关键词： cholangiocarcinoma native thiol total thiol dynamic disulphide oxidative stress

Pancreatic Involvement in Von Hippel-Lindau Syndrome: report of a Total Pancreatectomy Case and Literature review

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Surgical Science 2013年第2期4卷 151-153页

作者： kursat rahmi serin Fatih Yanar Orhan Agcaoglu Metin Keskin Ozgur Ceyhan Orhan Bilge Department of General Surgery Istanbul Medical Faculty Istanbul University Istanbul Turkey Department of radiology Istanbul Medical Faculty Istanbul University Istanbul Turkey

Von Hippel-Lindau (VHL) syndrome is a rare, autosomal dominantly inherited multicancer syndrome. Disease is predisposed by hemangioblastoma, renal cell carcinoma, pheochromocytoma, pancreatic islet cell and cystic tumors or epididymis tumors under the mutation or deletion at the tumor suppressor gene. Here we report a 42-year-old woman who had been operated for cerebellar hemangioblastoma and retinal angioma, and presented with recurrent, mild abdominal pain. In radiological imaging studies, multiple pancreatic cysts without nodulation were determined. Because of the mild abdominal pain and uncertain malignant potential of the cysts, total pancreatectomy was performed. She was discharged at the fifteenth day after the surgery without any problem. The patient has been followed for 62 months without any problem, and her diabetes mellitus is being controlled by medication.

关键词： Von Hippel-Lindau Syndrome Pancreatic Cyst Malignancy

Low eradication rate of Helicobacterpyloriwith triple 7-14 days and quadriple therapy in Turkey

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World Journal of Gastroenterology 2004年第5期10卷 668-671页

作者： Yuksel Gumurdulu Ender serin Birol zer Fazilet Kayaselcuk kursat Ozsahin Arif Mansur Cosar Murat Gursoy Gurden Gur Ugur Yilmaz Sedat Boyacioglu Faculty of Medicine Baskent UniversityDepartment of GastroenterologyAdana Teaching and Medical Research CenterAdanaTurkey Department of Pathology Adana Teaching and Medical Research CenterAdanaTurkey Department of Family Physician Adana Teaching and Medical Research CenterAdanaTurkey Faculty of Medicine Baskent UniversityDepartment of GastroenterologyAnkara HospitalAnkaraTurkey

AIM:The eradication rate of Helicobacter pylori (H pylori) shows variation among countries and regimens of treatment. We aimed to study the eradication rates of different regimens in our region and some factors affecting the rate of eradication. METHODS:One hundred and sixty-four H pylori positive patients (68 males,96 females;mean age:48±12 years) with duodenal or gastric ulcer without a smoking history were included in the *** patients were divided into three groups according to the treatment *** 20mg,clarithromycin 500mg,amoxicillin 1g were given twice daily for 1 week (Group Ⅰ) and 2 weeks (Group Ⅱ). Patients in Group Ⅲ received bismuth subsitrate 300mg, tetracyline 500mg and metronidazole 500mg four times daily in addition to Omeprazole 20mg twice *** biopsies each before and after treatment were obtained from antrum and corpus,and histopathologically evaluated. Eradication was assumed to be successful if no H pylorus was detected from four biopsy specimens taken after *** effects of factors like age,sex,H pylori density on antrum and corpus before treatment,the total H pylori density,and the inflammation scores on the rate of H pylori eradication were evaluated. rESULTS:The overall eradication rate was 42%.The rates in groups Ⅱ and Ⅲ were statistically higher than that in group Ⅰ (Prates of eradication were 24.5%, 40.7% and 61.5% in groups Ⅰ,Ⅱ and Ⅲ,*** eradication rate was negatively related to either corpus H pylori density or total H pylori density (Pr in the group in which the eradication failed in comparison to that with successful eradication (55 yr vs 39 yr,Prrelation between sex and H pylori eradication was found. CONCLUSION:Our rates of eradication were significantly lower when compared to those reported in *** believe that advanced age and high H pylori density are negative predictive factors for the rate of H pylori eradication.

关键词： Helicobacter pylori Adolescent Adult Aged Amoxicillin dosage Anti-Bacterial Agents Anti-Infective Agents Anti-Ulcer Agents Clarithromycin Comparative Study Drug Therapy, Combination Duodenal Ulcer Female Helicobacter Infections Humans Male Metronidazole Middle Aged Omeprazole Organometallic Compounds Stomach Ulcer Tetracycline Treatment Outcome Turkey

Chimera states in plasmonic nanoresonators

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Photonics research 2018年第5期6卷 427-433页

作者： EESA rAHIMI kursat SENDUr Faculty of Engineering and Natural Science Sabanci UniversityIstanbul 34956Turkey

The chimera state is the concurrent combination of synchronous and incoherent osdllations in a set of identical oscillators. In this study, we demonstrate the states for optical nanoresonators where the oscillators are designed based on a plasmonic dimer cavity. This resonator interchanges radiative energy with an active medium located at its ***, and therefore forms an amplitude-medlated oscillating system. Finite-difference time-domain studied for this system, and strong coupling is shown to force the array members to fully synchronize while weaker coupling causes chimera states in the array.

关键词： Chimera states plasmonic nanoresonators

On 2-Absorbing Quasi-Primary Ideals in Commutative rings

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Communications in Mathematics and Statistics 2016年第1期4卷 55-62页

作者： Unsal Tekir Suat Koç kursat Hakan Oral Kar Ping Shum Department of Mathematics Marmara UniversityIstanbulTurkey Department of Mathematics Yildiz Technical UniversityIstanbulTurkey Institute of Mathematics Yunnan UniversityKunming 650091People's Republic of China

Let r be a commutative ring with nonzero *** this article,weintroduce the notion of 2-absorbing quasi-primary ideal which is a generalization ofquasi-primary *** define a proper ideal I of r to be 2-absorbing quasi primaryif√1 is a 2-absorbing ideal of r.A number of results concerning 2-absorbing quasi-primary ideals and examples of 2-absorbing quasi-primary ideals are given.

关键词： Prime ideal 2-Absorbing ideal 2-Absorbing quasi-primary ideal