FINITE TYPE CURVE IN 3-DIMENSIONAL SASAKIAN MANIFOLD

Camci, Cetin,Hacisalihoglu, H. Hilmi Korean Mathematical Society 2010 대한수학회보 Vol.47 No.6

We study finite type curve in $R^3$(-3) which lies in a cylinder $N^2$(c). Baikousis and Blair proved that a Legendre curve in $R^3$(-3) of constant curvature lies in cylinder $N^2$(c) and is a 1-type curve, conversely, a 1-type Legendre curve is of constant curvature. In this paper, we will prove that a 1-type curve lying in a cylinder $N^2$(c) has a constant curvature. Furthermore we will prove that a curve in $R^3$(-3) which lies in a cylinder $N^2$(c) is finite type if and only if the curve is 1-type.

FINITE TYPE CURVE IN 3-DIMENSIONAL SASAKIAN MANIFOLD

Cetin Camci,H. Hilmi Hacisalihoglu 대한수학회 2010 대한수학회보 Vol.47 No.6

We study finite type curve in R3(-3) which lies in a cylin-der N2(c). Baikousis and Blair proved that a Legendre curve in R3(-3)of constant curvature lies in cylinder N2(c) and is a 1-type curve, con-versely, a 1-type Legendre curve is of constant curvature. In this paper,we will prove that a 1-type curve lying in a cylinder N2(c) has a constant curvature. Furthermore we will prove that a curve in R3(-3) which lies in a cylinder N2(c) is finite type if and only if the curve is 1-type.

Cyclooxygenase-2 Expression is not a Marker of Poor Survival in Lung Cancer

Turk, H. Mehmet,Camci, Celalettin,Sevinc, Alper,Bukyukberber, Suleyman,Sari, Ibrahim,Adli, Mustafa Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.1

Objective: Cyclooxygenase-2 (COX-2) has been claimed to play role in carcinogenesis and be related to a bad prognosis in tumours. The aim of this study was to investigate the relationship between COX-2 expression and clinical and pathological parameters in early and advanced stage lung cancer patients. Materials and Methods: A total of 73 patients with lung cancer (27 adenocarcinomas, 33 squamous cell carcinomas, 4 large cell carcinomas and 9 small cell cancer) were analysed retrospectively. COX-2 expression was evaluated by immunohistochemistry in resection materials or lung biopsies. Tumor cells demonstrating more intense staining than smooth muscle and endothelial cells were recorded as COX-2 positive. We investigated the correlation between increased COX-2 expression and histological type of the tumor, the stage of the disease and survival. Results: COX-2 expression was observed in 55% of the adenocarcinomas, 45% of the squamous cell carcinomas and 22% of the small cell carcinomas. No correlation was apparent between COX-2 expression and disease stage, histological type and the survival. Conclusion: The results of this study do not support COX-2 expression as an independent prognostic factor in lung cancer. However, since results of the literature are different, further studies made in larger series are needed.

THE SOURCE OF SEMIPRIMENESS OF RINGS

Aydin, Neset,Demir, Cagri,Camci, Didem Karalarlioglu Korean Mathematical Society 2018 대한수학회논문집 Vol.33 No.4

Let R be an associative ring. We define a subset $S_R$ of R as $S_R=\{a{\in}R{\mid}aRa=(0)\}$ and call it the source of semiprimeness of R. We first examine some basic properties of the subset $S_R$ in any ring R, and then define the notions such as R being a ${\mid}S_R{\mid}$-reduced ring, a ${\mid}S_R{\mid}$-domain and a ${\mid}S_R{\mid}$-division ring which are slight generalizations of their classical versions. Beside others, we for instance prove that a finite ${\mid}S_R{\mid}$-domain is necessarily unitary, and is in fact a ${\mid}S_R{\mid}$-division ring. However, we provide an example showing that a finite ${\mid}S_R{\mid}$-division ring does not need to be commutative. All possible values for characteristics of unitary ${\mid}S_R{\mid}$-reduced rings and ${\mid}S_R{\mid}$-domains are also determined.

Structural Reinforcement of Cell-Laden Hydrogels with Microfabricated Three Dimensional Scaffolds.

Cha, Chaenyung,Soman, Pranav,Zhu, Wei,Nikkhah, Mehdi,Camci-Unal, Gulden,Chen, Shaochen,Khademhosseini, Ali Royal Society of Chemistry 2014 Biomaterials Science Vol.2 No.5

<P>Hydrogels commonly used in tissue engineering are mechanically soft, thus often display structural weakness. Herein, we introduce a strategy for enhancing the structural integrity and fracture toughness of cell-laden hydrogels by incorporating a three-dimensional (3D) microfabricated scaffold as a structural element. A digital micromirror device projection printing (DMD-PP) system, a rapid prototyping technology which employs a layer-by-layer stereolithographic approach, was utilized to efficiently fabricate 3D scaffolds made from photocrosslinkable poly(ethylene glycol) diacrylate (PEGDA). The scaffold was incorporated into a photocrosslinkable gelatin hydrogel by placing it in a pre-gel solution, and inducing in situ hydrogel formation. The resulting scaffold-reinforced hydrogels demonstrated significant increase in ultimate stress and provided structural support for weak hydrogels. In addition, the scaffold did not affect the rigidity of hydrogels, as it was not involved in the crosslinking reaction to form the hydrogel. Therefore, the presented approach could avoid inadvertent and undesired changes in the hydrogel rigidity which is a known regulator of cellular activities. Furthermore, the biocompatibility of scaffold-reinforced hydrogels was confirmed by evaluating the viability and proliferation of encapsulated fibroblasts. Overall, the strategy of incorporating 3D scaffolds into hydrogels as structural reinforcements presented in this study will be highly useful for enhancing the mechanical toughness of hydrogels for various tissue engineering applications.</P>

Microfluidics-Assisted Fabrication of Gelatin-Silica Core–Shell Microgels for Injectable Tissue Constructs

Cha, Chaenyung,Oh, Jonghyun,Kim, Keekyoung,Qiu, Yiling,Joh, Maria,Shin, Su Ryon,Wang, Xin,Camci-Unal, Gulden,Wan, Kai-tak,Liao, Ronglih,Khademhosseini, Ali American Chemical Society 2014 Biomacromolecules Vol.15 No.1

<P/><P>Microfabrication technology provides a highly versatile platform for engineering hydrogels used in biomedical applications with high-resolution control and injectability. Herein, we present a strategy of microfluidics-assisted fabrication photo-cross-linkable gelatin microgels, coupled with providing protective silica hydrogel layer on the microgel surface to ultimately generate gelatin-silica core–shell microgels for applications as in vitro cell culture platform and injectable tissue constructs. A microfluidic device having flow-focusing channel geometry was utilized to generate droplets containing methacrylated gelatin (GelMA), followed by a photo-cross-linking step to synthesize GelMA microgels. The size of the microgels could easily be controlled by varying the ratio of flow rates of aqueous and oil phases. Then, the GelMA microgels were used as in vitro cell culture platform to grow cardiac side population cells on the microgel surface. The cells readily adhered on the microgel surface and proliferated over time while maintaining high viability (∼90%). The cells on the microgels were also able to migrate to their surrounding area. In addition, the microgels eventually degraded over time. These results demonstrate that cell-seeded GelMA microgels have a great potential as injectable tissue constructs. Furthermore, we demonstrated that coating the cells on GelMA microgels with biocompatible and biodegradable silica hydrogels via sol–gel method provided significant protection against oxidative stress which is often encountered during and after injection into host tissues, and detrimental to the cells. Overall, the microfluidic approach to generate cell-adhesive microgel core, coupled with silica hydrogels as a protective shell, will be highly useful as a cell culture platform to generate a wide range of injectable tissue constructs.</P>

Weekly Topotecan for Recurrent Small Cell Lung Cancer - a Retrospective Anatolian Medical Oncology Group Study

Altinbas, Mustafa,Kalender, Mehmet Emin,Oven, Basak,Sevinc, Alper,Karaca, Halit,Kaplan, M. Ali,Alici, Suleyman,Arpaci, Erkan,Yildiz, Ramazan,Uncu, Dogan,Camci, Celalettin,Gumus, Mahmut Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.6

Aim: To evaluate efficacy and tolerability of topotecan treatment for recurrent small cell lung carcinoma. Patients and Methods: A total of 62 patients were evaluated retrospectively. Statistical analysis was performed using GraphPad Instat (version 3.05). Results: DFifty five of patients (89%) were male and 7 (11%) were female. Median age was $56.7{\pm}9.3$ (34-75). Forty eight of patients (80%) were extensive stage (ES) at the time of diagnosis. Fifty of the patients (80.6 Medical Oncology Clinic) were given median 5.36 cycles of cisplatin-etoposide (2-8 cycles). Time to recurrence was $15.6{\pm}6.13$ weeks in patients with limited stage (LS) and $6.3{\pm}3.82$ weeks in extensive stage (ES) (p<0.0001). Overall survival was $14.0{\pm}6.08$ months in ES and $17.9{\pm}6.88$ months in LS. The difference between two groups was statistically meaningful (p=0.0447). The overall survival of the patients was $14.8{\pm}6.43$ months (4.5-40 months). In terms of survival, there was no difference between males and females (p=0.1171). In 17 (27%) patients who were refractory to topotecan or in whom progression occurred other chemotherapies were used. Conclusion: Small cell lung cancer is chemosensitive, but recurrences occur in short time. Other chemotherapy regimens are used in progression. Topotecan is one of them. Patients who were young and in whom recurrences occur late had given better response to topotecan. Because of the retrospective nature of the study, we couldn't reach the records exactly and consequently, rate and duration of response couldn't be calculated. In recurrent SCLC topotecan is one of the treatment choices. But both hematological and non hematological side effects should be taken into consideration.

Efficacy and Toxicity of Gemcitabine Plus Docetaxel Combination as a Second Line Therapy for Patients with Advanced Stage Soft Tissue Sarcoma

Ali Osman, Kaya,Suleyman, Buyukberber,Metin, Ozkan,Necati, Alkis,Alper, Sevinc,Nuriye Yildirim, Ozdemir,Suleyman, Alici,Onur, Esbah,Veli, Berk,Celalettin, Camci,Arife, Ulas,Ugur, Coskun,Mustafa, Benek Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.2

Purpose: To assess the safety and efficacy of a gemcitabine plus docetaxel regimen as a second line therapy for patients with advanced soft tissue sarcoma (STS) resistant to doxorubicin and ifosfamide-based therapy. Patients and Methods: Medical records of 64 patients with advanced STS who received gemcitabine plus docetaxel regimen as a second line treatment between May 2006 and June 2011 were examined. All patients had been previously treated with doxorubicin plus ifosfamide-based regimen at first line setting. Patients received gemcitabine 900 $mg/m^2$ on days one and eight intravenously over 90 minutes, followed by docetaxel 75 $mg/m^2$ on day eight intravenously over one hour. Cycles were repeated every 3 weeks. Results: The male-to-female ratio was 37/27 and the median age was 44 years (range; 19-67 years). Objective responses were observed in 13 (20.3 %) patients (2 CR, 11 PR) and stable disease in 21 (32.8 %). Total clinical benefit (CR+PR+SD) was observed in 34 (53.1 %). Median overall survival (OS) was 18 months (95% confidence interval (CI):12.1-23.9) and Median time to progression (TTP) was 4.8 months (95% CI: 3.6-6). A total of 243 cycles of chemotherapy were administered. The median number of cycle was 3 (range;1-11). The most common grade 3-4 hematologic toxicity was neutropenia (35.9 %). The most common nonhematologic toxicities consisted of nausea/vomiting (37.5 %), mucositis (32.8 %), peripheral neuropathy (29.7%), and fatigue (26 %). There was no toxicity-related death. Conclusion: The combination of gemcitabine plus docetaxel is an active and tolerable regimen as a second line therapy for patients with advanced soft tissue sarcoma who have failed doxorubicin and ifosfamide-based therapy.