ON GENERALIZATIONS OF SKEW QUASI-CYCLIC CODES

Bedir, Sumeyra,Gursoy, Fatmanur,Siap, Irfan Korean Mathematical Society 2020 대한수학회보 Vol.57 No.2

In the last two decades, codes over noncommutative rings have been one of the main trends in coding theory. Due to the fact that noncommutativity brings many challenging problems in its nature, still there are many open problems to be addressed. In 2015, generator polynomial matrices and parity-check polynomial matrices of generalized quasi-cyclic (GQC) codes were investigated by Matsui. We extended these results to the noncommutative case. Exploring the dual structures of skew constacyclic codes, we present a direct way of obtaining parity-check polynomials of skew multi-twisted codes in terms of their generators. Further, we lay out the algebraic structures of skew multipolycyclic codes and their duals and we give some examples to illustrate the theorems.

Fabrication of Two-Layered $Al-B_4C$ Composites by Conventional Hot Pressing Uuder Nitrogen Atmosphere and Their Characterization

Bedir Fevzi The Korean Society of Mechanical Engineers 2006 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.20 No.7

In this study, we describe the conventional hot pressing (CHP) of layered $Al-B_4C$ composites and their characterization. The matrix alloy Al-5 wt.%Cu was prepared from elemental powder mixtures. The metal and B4C powders were mixed to produce either $Al-Cu-10vol.%B_4C$ or $Al-Cu-30vol.%B_4C$ combinations. Then, these powder mixtures were stacked as layers in the hot pressing die to form a two-layered composite. Hot pressing was carried out under nitrogen atmosphere to produce $30\times40\times5mm$ specimens. Microstructural features and age hardening characteristics of composites were determined by specimens cut longitudinally. The flexural strength of both layered composites and their monolithic counterparts were investigated via three point bending tests. In the case of layered specimens of both $10vol.%B_4C$ and $30vol.%B_4C$ containing layers were loaded for three-point test. The results show that a homogeneous distribution of $B_4C$ particles in the matrix alloy which is free of pores, can be obtained by CHP method. The ageing behavior of the composites was found to be influenced by the reinforced materials, i.e. higher hardness values were reached in 8 hrs for the composites than that for the matrix alloy. Flexural strength test showed that two-layered composites exhibited improved damage tolerance depending on layer arrangement. Microstructural investigation of the fracture surfaces of the bending specimens was performed by means of scanning electron microscope (SEM). While layer with lower reinforcement content exhibited large plastic deformation under loading, the other with higher reinforcement content exhibited less plastic deformation.

On generalizations of skew quasi-cyclic codes

Sumeyra Bedir,Fatmanur Gursoy,Irfan Siap 대한수학회 2020 대한수학회보 Vol.57 No.2

In the last two decades, codes over noncommutative rings have been one of the main trends in coding theory. Due to the fact that noncommutativity brings many challenging problems in its nature, still there are many open problems to be addressed. In 2015, generator polynomial matrices and parity-check polynomial matrices of generalized quasi-cyclic (GQC) codes were investigated by Matsui. We extended these results to the noncommutative case. Exploring the dual structures of skew constacyclic codes, we present a direct way of obtaining parity-check polynomials of skew multi-twisted codes in terms of their generators. Further, we lay out the algebraic structures of skew multi-polycyclic codes and their duals and we give some examples to illustrate the theorems.

Fabrication of Two-Layered Al-B₄C Composites by Conventional Hot Pressing Uuder Nitrogen Atmosphere and Their Characterization

Fevzi Bedir 대한기계학회 2006 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.20 No.7

In this study, we describe the conventional hot pressing (CHP) of layered Al-B₄C composites and their characterization. The matrix alloy Al-5 wt.%Cu was prepared from elemental powder mixtures. The metal and B₄C powders were mixed to produce either Al-Cu-10vol.%B₄C or Al-Cu-30vol.%B₄C combinations. Then, these powder mixtures were stacked as layers in the hot pressing die to form a two-layered composite. Hot pressing was carried out under nitrogen atmosphere to produce 30 × 40 × 5 ㎜ specimens. Microstructural features and age hardening characteristics of composites were determined by specimens cut longitudinally. The flexural strength of both layered composites and their monolithic counterparts were investigated via three point bending tests. In the case of layered specimens of both 10vol.%B₄C and 30vol.%B₄C containing layers were loaded for three-point test. The results show that a homogeneous distribution of B₄C particles in the matrix alloy which is free of pores, can be obtained by CHP method. The ageing behavior of the composites was found to be influenced by the reinforced materials, i.e. higher hardness values were reached in 8 hrs for the composites than that for the matrix alloy. Flexural strength test showed that two-layered composites exhibited improved damage tolerance depending on layer arrangement. Microstructural investigation of the fracture surfaces of the bending specimens was performed by means of scanning electron microscope (SEM). While layer with lower reinforcement content exhibited large plastic deformation under loading, the other with higher reinforcement content exhibited less plastic deformation.

Fabrication of Two-Layered Al-B4C Composites by Conventional Hot Pressing Under Nitrogen Atmosphere and Their Characterization

Fevzi Bedir 대한기계학회 2006 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.20 No.7

Relationships Between C-Kit Expression and Mean Platelet Volume in Benign, Preneoplastic and Neoplastic Endometrium

Sehitoglu, Ibrahim,Bedir, Recep,Ural, Ulku Mete,Gucer, Hasan,Yurdakul, Cuneyt,Cure, Medine Cumhur,Cure, Erkan,Yuce, Suleyman,Sahin, Figen Kir Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.4

Background: c-Kit is a proto-oncogene that encodes a tyrosine kinase receptor (CD117). Mean platelet volume (MPV) is a useful marker for demonstrating thrombocyte function. We aimed to investigate whether c-kit is expressed in benign, preneoplastic and neoplastic endometrial tissues and whether MPV has a relation with c-kit expression and its intensity. Materials and Methods: c-Kit expression was investigated immunohistochemically in 10 samples of normal endometrium (n=10), simple endometrial hyperplasia (5 cases with atypia and 10 cases without atypia), complex endometrial hyperplasia (10 cases with atypia and 10 cases without atypia) and endometrial cancer (EC) (10 cases grade I and 10 cases grade II) and MPV of all cases was checked. Results: c-Kit expression was observed at very low rates in cases with normal endometrial tissues (NE) and in hyperplasia without atypia. c-Kit expression and immunostaining were strong in endometrial atypia and EC. MPV levels of complex atypical endometrial hyperplasia (CAEH) (p:0.002), EC grade I (ECG I) (p<0.001) and EC grade II (ECG II) (p<0.001) were significantly elevated when compared with the NE group. Both c-kit expression and intensity of immunostaining had a positive correlation with MPV level. Conclusions: While c-kit expression and intensity of immunostaining were mildly positive in NE and hyperplasia without atypia, they were clearly observed in EC and hyperplasia with atypia. As c-kit expression is related to the mutagenesis a long-term followup may be needed in these cases. A high MPV level may be a good test for demonstrating c-kit expression and intensity of immunostaining.

The effect of adenosine triphosphate on propofol-induced myopathy in rats: a biochemical and histopathological evaluation

Kezban Tuna Ozkaloglu Erdem,Zehra Bedir,Irem Ates,Ufuk Kuyrukluyildiz,Taha Abdulkadir Coban,Gulce Naz Yazici,Yusuf Kemal Arslan,Zeynep Suleyman,Halis Suleyman 대한약리학회 2021 The Korean Journal of Physiology & Pharmacology Vol.25 No.1

Propofol infusion syndrome characterized by rhabdomyolysis, metabolic acidosis, kidney, and heart failure has been reported in long-term propofol use for sedation. It has been reported that intracellular adenosine triphosphate (ATP) is reduced in rhabdomyolysis. The study aims to investigate the protective effect of ATP against possible skeletal muscle damage of propofol in albino Wistar male rats biochemically and histopathologically. PA-50 (n = 6) and PA-100 (n = 6) groups of animals was injected intraperitoneally to 4 mg/kg ATP. An equal volume (0.5 ml) of distilled water was administered intraperitoneally to the P-50, P-100, and HG groups. One hour after the administration of ATP and distilled water, 50 mg/kg propofol was injected intraperitoneally to the P-50 and PA-50 groups. This procedure was repeated once a day for 30 days. The dose of 100 mg/kg propofol was injected intraperitoneally to the P-100 and PA-100 groups. This procedure was performed three times with an interval of 1 days. Our experimental results showed that propofol increased serum CK, CK-MB, creatinine, BUN, TP I, ALT, AST levels, and muscle tissue MDA levels at 100 mg/kg compared to 50 mg/kg and decreased tGSH levels. At a dose of 100 mg/kg, propofol caused more severe histopathological damage compared to 50 mg/kg. It was found that ATP prevented propofol-induced muscle damage and organ dysfunction at a dose of 50 mg/kg at a higher level compared to 100 mg/kg. ATP may be useful in the treatment of propofol-induced rhabdomyolysis and multiple organ damage.

Somatostatin Receptor 2 and 5 Expressions in Gastroenteropancreatic Neuroendocrine Tumors in Turkey

Yerci, Omer,Sehitoglu, Ibrahim,Ugras, Nesrin,Cubukcu, Erdem,Yuce, Suleyman,Bedir, Recep,Cure, Erkan Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.10

Background: Gastroenteropancreatic neuroendocrine tumors (GNs) are slow growing and although their incidence has increased in recent years, they are relatively rarely seen. Somatostatin analogues are used in the treatment of GNs that express somatostatin receptor (SR). We aimed to investigate the expression of SR2 and SR5 in GNs. Materials and Methods: In this study the expression of SR2 and SR5 was investigated immunohistochemically in 49 cases (26 males, 23 females) diagnosed and graded with GN according to the World Health Organization classification 2010. Results: The percentage of SR2 staining was 91.0% in grade 1, 82.8% in grade 2 and 100% in grade 3. On the other hand, the percentage of SR5 staining was 81.8% % in grade 1, 60.0% in grade 2 and 0% in grade 3. According to the tumor localization, the percentages of SR2 expression were as follows: pancreas 85.7%, stomach 100%, small bowel 70%, appendix 85.7% and rectum 100%. The percentages of SR5 expression were: pancreas 61,9%, stomach 37.5%, small bowel 70%, appendix 71.5% and rectum 66.6%. There was a significant negative correlation between ki67 percentage and SR5 expression (r=-0.341, p=0.016). Conclusions: In this study, GNs were found to highly express SR2 and SR5. Although the expression of SR2 and SR5 changed according to tumor localization, the expression of SR2 was higher than the expression of SR5 in GN. There was a significant negative correlation between ki67 and SR5. Accordingly, SR5 may be a prognostic indicator of GN.

Synovial Sarcoma Mimicking Myositis Ossificans

( Mehmet Sabri Balik ),( Adem Erkut ),( Yılmaz Guvercin ),( Recep Bedir ) 대한슬관절학회 2016 대한슬관절학회지 Vol.28 No.3

A calcification mass was incidentally found in the soft tissue of a patient who had a history of trauma to the extremity during examination. The patient had no symptom. The pathological analysis of the mass revealed it was an early phase synovial sarcoma (SS). The diagnosis was made before the onset of symptoms and proper surgical intervention was performed. Therefore, in case of a <1 cm lesion clinically suspicious of myositis ossificans, SS should be taken into consideration as a possible diagnosis.