Optimum design of parabolic and circular arches with varying cross section

Uzman, Umit,Daloglu, Ayse,Saka, M. Polat Techno-Press 1999 Structural Engineering and Mechanics, An Int'l Jou Vol.8 No.5

A structural optimization process is presented for arches with varying cross-section. The optimality criteria method is used to develop a recursive relationship for the design variables considering displacement, stresses and minimum depth constraints. The depth at the crown and at the support are taken as design variables first. Then the approach is extended by taking the depth values of each joint as design variable. The curved beam element of constant cross section is used to model the parabolic and circular arches with varying cross section. A number of design examples are presented to demonstrate the application of the method.

Combined spinal-epidural anesthesia in laparoscopic appendectomy

Sinan Uzman,Turgut Donmez,Vuslat Muslu Erdem,Adnan Hut,Dogan Yildirim,Muzaffer Akinci 대한외과학회 2017 Annals of Surgical Treatment and Research(ASRT) Vol.92 No.4

Purpose: Laparoscopic appendectomy (LA) is routinely performed under general, not regional anesthesia. This study assessed the feasibility, efficacy, and side effects of combined spinal-epidural anesthesia (CSEA) in LA. Methods: Thirty-three American Society of Anesthesiologist (ASA) physical status classification grade I patients underwent LA under CSEA. CSEA was performed using the needle-through-needle technique at the L3–L4 interspace. Preoperative and postoperative adverse events related to CSEA, patient satisfaction, and postoperative pain levels were recorded. Results: LA under CSEA was performed successfully in 33 patients (84.6%). Peroperatively, right shoulder pain was observed in 8 patients (24.1%), abdominal discomfort in 6 (18.2%), anxiety in 5 (15.2%), hypotension in 2 (6.1%) and nausea-vomiting in 1 (3%). In the first 24 hours after LA, headache, urinary retention, right shoulder pain, and postoperative nausea/vomiting (PONV) occurred in 18.1%, 12.1%, 9.1%, and 0% of patients, respectively. In the first 6 hours postoperation, no patients had operation-site pain that required analgesic treatment. Thirty-one patients (94%) evaluated their satisfaction with the procedure as good or moderate. Conclusion: CSEA is an efficient and suitable anesthesia technique in LA for ASA physical status classification grade I healthy patients. CSEA is associated with good postoperative pain control and the absence of PONV and intubation-associated complications.

Optimal design of laminated composite plates to maximise fundamental frequency using MFD method

Topal, Umut,Uzman, Umit Techno-Press 2006 Structural Engineering and Mechanics, An Int'l Jou Vol.24 No.4

This paper deals with optimal fibre orientations of symmetrically laminated fibre reinforced composite structures for maximising the fundamental frequency of small-amplitude. A set of fiber orientation angles in the layers are considered as design variable. The Modified Feasible Direction method is used in order to obtain the optimal designs. The effects of number of layers, boundary conditions, laminate thicknesses, aspect ratios and in-plane loads on the optimal designs are studied.

Serum 8 Hydroxydeoxyguanosine and Cytotoxin Associated Gene A as Markers for Helicobacter pylori Infection

Yeniova, Abdullah Ozgur,Uzman, Metin,Kefeli, Ayse,Basyigit, Sebahat,Ata, Naim,Dal, Kursat,Guresci, Servet,Nazligul, Yasar Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.13

Background: Helicobacter pylori (H.pylori) is associated with chronic gastritis, peptic ulcers, gastric adenocarcinomas and mucosa associated tissue lymphomas. Cytotoxin associated gene A (CagA) is one of the virulence factors of H.pylori. It is hypothesized that reactive oxygen species (ROS) play roles in H.pylori associated disease especially in development of gastric adenocarcinoma. Individuals infected with H.pylori bearing CagA produce more ROS than others. 8-hydroxydeoxyguanosine (8OHdG) is an in vitro marker of DNA damage and oxidative stress. The aim of this study was to investigate the relationship between 8OHdG level, H.pylori infection and CagA and alterations of serum 8OHdG level after H.pylori eradication. Materials and Methods: Patients admitted with dyspeptic complaints and upper gastrointestinal endoscopy were assessed. H.pylori was determined from histopathology of specimens. Serum 8OHdG levels of three groups (H.pylori negative, H. pylori positive CagA negative and H.pylori positive CagA positive) were compared. Patients with H.pylori infection received eradication therapy. Serum 8OHdG levels pretreatment and posttreatment were also compared. Results: In total, 129 patients (M/F, 57/72) were enrolled in the study. Serum 8OHdG level of H.pylori negative, H. pylori positive CagA negative and H.pylori positive CagA positive groups were significantly different ($5.77{\pm}1.35ng/ml$, $5.43{\pm}1.14ng/ml$ and $7.57{\pm}1.25ng/ml$ respectively, p=0.05). Furthermore, eradication therapy reduced serum 8OHdG level ($6.10{\pm}1.54ng/ml$ vs $5.55{\pm}1.23ng/ml$, p=0.05). Conclusions: Individuals infected with H.pylori bearing CagA strains have the highest serum 8OHdG level and eradication therapy decreases the serum 8OHdG level. To the best of our knowledge this is the first study that evaluated the effect of CagA virulence factor on serum 8OHdG level and the effect of eradication therapy on serum 8OHdG levels together. Eradication of CagA bearing H.pylori may prevent gastric adenocarcinoma by decreasing ROS. 8OHdG level may thus be a good marker for prevention from gastric adenocarcinoma.

Laparoscopic cholecystectomy under spinal-epidural anesthesia vs. general anaesthesia

Turgut Donmez,Vuslat Muslu Erdem,Sinan Uzman,Dogan Yildirim,Huseyin Avaroglu,Sina Ferahman,Oguzhan Sunamak 대한외과학회 2017 Annals of Surgical Treatment and Research(ASRT) Vol.92 No.3

Purpose: Laparoscopic cholecystectomy (LC) is usually performed under the general anesthesia (GA). Aim of the study is to investigate the availability, safety and side effects of combined spinal/epidural anesthesia (CSEA) and comparison it with GA for LC. Methods: Forty-nine patients who have a LC plan were included into the study. The patients were randomly divided into GA (n = 25) and CSEA (n = 24) groups. Intraoperative and postoperative adverse events, postoperative pain levels were compared between groups. Results: Anesthesia procedures and surgeries for all patients were successfully completed. After the organization of pneumoperitoneum in CSEA group, 3 patients suffered from shoulder pain (12.5%) and 4 patients suffered from abdominal discomfort (16.6%). All these complaints were recovered with IV fentanyl administration. Only 1 patient developed hypotension which is recovered with fluid replacement and no need to use vasopressor treatment. Postoperative shoulder pain was significantly less observed in CSEA group (25% vs. 60%). Incidence of postoperative nausea and vomiting (PONV) was less observed in CSEA group but not statistically significant (4.2% vs. 20%). In the group of CSEA, 3 patients suffered from urinary retention (12.5%) and 2 patients suffered from spinal headache (8.3%). All postoperative pain parameters except 6th hour, were less observed in CSEA group, less VAS scores and less need to analgesic treatment in CSEA group comparing with GA group. Conclusion: CSEA can be used safely for laparoscopic cholecystectomies. Less postoperative surgical field pain, shoulder pain and PONV are the advantages of CSEA compared to GA.

Two-port laparoscopic appendectomy assisted with needle grasper comparison with conventional laparoscopic appendectomy

Turgut Donmez,Adnan Hut,Huseyin Avaroglu,Sinan Uzman,Dogan Yildirim,Sina Ferahman,Erdinc Cekic 대한외과학회 2016 Annals of Surgical Treatment and Research(ASRT) Vol.91 No.2

Purpose: The 2-port laparoscopic appendectomy technique (TLA) is between the conventional 3-port and single-port laparoscopic appendectomy surgeries. We compared postoperative pain and cosmetic results after TLA with conventional laparoscopic appendectomy (CLA) by a 3-port device. Methods: Patients undergoing TLA were matched with patients undergoing CLA between February 2015 and November 2015 at the same institution. Thirty-two patients underwent TLA with a needle grasper. The appendix was secured by a percutaneous organ-holding device (needle grasper), then removed through a puncture at McBurney’s point. Another 38 patients underwent CLA. Patient demographics, operative details, and postoperative outcomes were collected and evaluated. Results: One patient in the TLA group developed a wound infection and 1 patient in the CLA group developed a postoperative intra-abdominal abscess and 3 wound infections. There was no significant difference between the groups when comparing the length of hospital stay, time until oral intake, and other complications. The pain score in the first 12 hours after surgery was significanly higher in CLA group than the TLA group (P < 0.001). Operative time was significantly shorter in the CLA group compared to the TLA group (P < 0.001). Conclusion: TLA using a needle grasper was associated with a significantly lower pain score 12 hours after surgery, better cosmetic results, and lower cost, than the CLA 3-port procedure because of the fewer number of ports.