Comparison of the effects of on-pump and off-pump coronary artery bypass surgery on cerebral oxygen saturation using near-infrared spectroscopy

Guray Demir,Zafer Çukurova,Gülay Eren,Oya Hergünsel 대한마취통증의학회 2014 Korean Journal of Anesthesiology Vol.67 No.6

Background: Central nervous system complications are the most clinically important of those affecting mortality in patientsundergoing coronary artery surgery. Newly developed sophisticated techniques and surgical interventions obviatingthe need for cardiopulmonary pumps have facilitated avoidance of these complications. In this study, we comparedthe impact of on-pump and off-pump coronary artery bypass surgery on cerebral oxygenation using near-infrared spectroscopy. Methods: This study included 40 patients with no comorbidities who were scheduled for on-pump (n = 20) and offpump(n = 20) cardiac surgery. Preoperative and postoperative Standardized Mini-Mental State Examination (SMMSE)scores, perioperative mean arterial blood pressure (MAP), hematocrit (Hct), peripheral oxygen saturation (SpO2), regionalcerebral oximetry values (rSO2), body temperature, and partial pressure of carbon dioxide (PCO2) were recorded,for all patients. Intergroup and intragroup comparisons were then performed. Results: The mean operative time was longer in the on-pump group. SMMSE scores were similar and relevant postoperativevalues were lower in both groups. Perioperative MAP, PCO2, and SpO2 were similar in both groups. SpO2 and PCO2did not differ from baseline levels in either group, while the postextubation MAP at 2 h postoperatively remained low. Hct levels decreased during the perioperative and postoperative periods, while the body temperature declined perioperativelyand to a greater degree in the on-pump group. The intraoperative and postoperative rSO2 decreased in both groups. In the on-pump group, the decrease in rSO2 was more prominent during the interval between the start and closure of thesternotomy. Conclusions: Physiological alterations that occur during coronary artery surgery affect cerebral oxygenation duringand after the operation irrespective of the application of a cardiopulmonary pump. Cerebral oxygenation decreases to agreater extent during on-pump surgery; however, probably because of the neuroprotective effects of hypothermia, thepostoperative changes resemble those of off-pump surgery.

Shear Strength of Steel Fiber Reinforced Concrete (SFRC) Slender Beams

Guray Arslan 대한토목학회 2014 KSCE JOURNAL OF CIVIL ENGINEERING Vol.18 No.2

In the last four decades, many equations have been proposed to estimate the shear strength of Steel Fiber Reinforced Concrete (SFRC) beams. However, in terms of accuracy and uniformity of the prediction, there is considerable diversity between existing test results and researchers’ predictions. In this study, by using the basic principle of mechanics and considering the slenderness effect of SFRC beams without stirrups, a new design expression is proposed for the shear strength of SFRC beams. The proposed equation and researchers’ predictions are compared to the test results of 170 SFRC beams without stirrups. It is found that the proposed equation shows good agreement with regard to the existing test results.

Growth Performance, Meat Quality and Caecal Coliform Bacteria Count of Broiler Chicks Fed Diet with Green Tea Extract

Erener, Guray,Ocak, Nuh,Altop, Aydin,Cankaya, Soner,Aksoy, Hasan Murat,Ozturk, Ergin Asian Australasian Association of Animal Productio 2011 Animal Bioscience Vol.24 No.8

This study was conducted to investigate the effect of dietary green tea extract (GTE) on the performance, carcass and gastrointestinal tract (gut) traits, caecal coliform bacteria count, and pH and color (CIE $L^*$, $a^*$, and $b^*$) values of the breast muscle in broilers. A total number of 600 day-old broilers (Ross 308) was allocated to three treatments with four replicates containing 50 (25 males and 25 females) birds. The dietary treatments consisted of the basal diet as the control (0GTE) and diets with GTE at 0.1 (0.1GTE) or 0.2 (0.2GTE) g/kg. Body weights and the feed intake of broilers were measured at 1, 21 and 42 days, the feed intake was measured for different periods and the feed conversion ratio was calculated accordingly. At 42 day four birds per replicate were slaughtered for the determination of carcass and organ weights, caecal coliform bacteria count, and also quality of the breast muscle. The dietary GTE increased the body weight, feed efficiency, carcass weight and dressing percentage and decreased caecal coliform bacteria count of broilers (p<0.05). The 0GTE broilers consumed (p<0.01) less feed than the 0.1GTE birds in the entire experimental period. The relative abdominal fat weight and gut length of broilers in the 0.2GTE were tended to be lower (p<0.07) than those in the 0GTE group. The breast meat from 0.1GTE birds had a lower pH value when compared to that from 0GTE birds. The 0.1GTE broilers had lighter breast meat than 0GTE and 0.2GTE birds. The dietary GTE increased $a^*$ and $b^*$ values of the breast meat. Thus this product appeared to have a measurable impact on CIE color values of the breast meat in broilers. The results of the present study may indicate that the improved production results in the group with added GTE are directly connected with physiological mechanisms such as the regulation of the caecal micro-flora.

Management of Sacral Tumors Requiring Spino-Pelvic Reconstruction with Different Histopathologic Diagnosis: Evaluation with Four Cases

Murat Arıkan,Guray Togral,Askin Esen Hasturk,Fevzi Kekec,Murat Parpucu,Safak Gungor 대한척추외과학회 2015 Asian Spine Journal Vol.9 No.6

In this retrospective study, surgical results of four patients with sacral tumors having disparate pathologic diagnoses, who were treated with partial or total sacrectomy and lumbopelvic stabilization were abstracted. Two patients were treated with partial sacral resection and two patients were treated with total sacrectomy and spinopelvic fixation. Fixation methods included spinopelvic fixation with rods and screws in two cases, reconstruction plate in one case, and fresh frozen allografts in two cases. Fibular allografts used for reconstruction accelerated bony union and enhanced the stability in two cases. Addition of polymethyl methacrylate in the cavity in the case of a giant cell tumor had a positive stabilizing effect on fixation. As a result, we can conclude that mechanical instability after sacral resection can be stabilized securely with lumbopelvic fixation and polymethyl methacrylate application or addition of fresh frozen allografts between the rods can augment the stability of the reconstruction.

Endometrial polyps: Is the prediction of spontaneous regression possible?

( Semra Yuksel ),( Guray Tuna ),( Hale Goksever Celik ),( Suleyman Salman ) 대한산부인과학회 2021 Obstetrics & Gynecology Science Vol.64 No.1

Objective Endometrial polyps have been considered as a hyperplastic growth of endometrial stromal and glandular tissues. Even asymptomatic polyps in premenopausal women are usually removed as soon as they are diagnosed, although it is still unknown how often endometrial polyps disappear spontaneously. The aim of this study was to investigate the regression rate of endometrial polyps and the possible factors related to their spontaneous regression. Methods A total of 197 women with endometrial polyps were treated with operative hysteroscopy between January 2017 and April 2019 at our tertiary center. Of these, 123 patients who preferred conservative follow-up were enrolled in the study. Clinical and pathological data were obtained from electronic medical records. Results Patients with endometrial polyps were followed up for a median period of 62 days (range 30-360 days). Most women with endometrial polyps (84%) were reported to have gynecologic symptoms. Spontaneous polyp regression was observed in 28 (23%) patients who underwent surgery reevaluation. Patient age (<45 years), premenopausal period, and polyp size (<2 cm) were found to be associated with spontaneous endometrial polyp regression (P<0.05). We also observed more polyp regression in women with abnormal uterine bleeding (P=0.05). Second-look hysteroscopy showed that all postmenopausal women had persistent endometrial polyps. Conclusion Patient age (<45 years), premenopausal period, polyp size (<2 cm), and abnormal uterine bleeding may be associated with spontaneous endometrial polyp regression.

Sclerosing Extramedullary Hematopoietic Tumor Mimicking Intra-abdominal Sarcoma

Serap Karaarslan,Nalan Nese,Guray Oncel,Nazan Ozsan,Taner Akalin,Hasan Kaplan,Filiz Buyukkececi,Mine Hekimgil 대한병리학회 2015 Journal of Pathology and Translational Medicine Vol.49 No.4

Voluntary Intake of Insoluble Granite-grit Offered in Free Choice by Broilers: Its Effect on Their Digestive Tract Traits and Performances

Garipoglu, Ali Vaiz,Erener, Guray,Ocak, Nuh Asian Australasian Association of Animal Productio 2006 Animal Bioscience Vol.19 No.4

In this study, the effects of granite-grit offered free-choice on voluntary intakes of grit and subsequently on some morphologic traits of the digestive tract and performance of broilers were investigated. A total of 240 7d-old male broiler chicks (Ross 308) were allotted randomly to 10 floor pens supplied with wood shavings. The experiment lasted for 42 days. There were 2 dietary treatments, each consisting of 5 replicates. Each replicate consisted of 24 birds kept in an experimental unit with a floor size of $2{\times}2m$. Dietary treatments consisted of control (C) in which broilers were fed standard broiler rations, and acid insoluble granite-grit choice (AIGG) in which broilers were fed standard broiler rations and grit in separate troughs. Mean amounts consumed varied quite widely from week to week, but on average broilers ate 3.41 g per d per bird during the experimental period. Birds had a higher voluntary intake of granite-grit at an early age (7 to 21 d of age) than later (22 to 42 d of age). The voluntary intake of granite-grit of AIGG broilers increased (p<0.05) from 2.7 g/day at 7-14 d to 4.4 g at 15-21 d of age, and then it decreased to 3.4, 3.2 and 3.4 g/day between 22-28, 29-35 and 36-42 d of age, respectively. This level of grit intake increased (p<0.05) weights of empty gizzard (0.97 vs. 1.30 g), edible inner organs (3.51 vs. 3.69 g), and length of gut (8.86 vs. 9.01 cm) as a proportion of body weight and the content of insoluble ash (8.4 vs. 42.2 g/kg) in the faeces compared to the control group. Feeding free-choice grit had little or no effect on final live weights (2,542 vs. 2,543 g), daily gains (69 vs. 69 g), carcass weights (1,924 vs. 1,911), dressing percentages (75.6% vs. 75.1%) and feed efficiencies (1.69 vs. 1.66). Birds given grit did not gain more weight than those not given grit but they tended to have (p<0.07) lower feed intake (116.7 vs. 114.5 g), and consequently lower protein and energy intake. In conclusion, the granite-grit consumed voluntarily by broilers increased gut length and empty gizzard weight without affecting growth performance of broilers. Thus, it can be assumed that the voluntary consumption of granite-grit was too low to affect performance.

Predicting diagonal cracking strength of RC slender beams without stirrups using ANNs

Riza S.O. Keskin,Guray Arslana 사단법인 한국계산역학회 2013 Computers and Concrete, An International Journal Vol.12 No.5

Numerous studies have been conducted to understand the shear behavior of reinforced concrete (RC) beams since it is a complex phenomenon. The diagonal cracking strength of a RC beam is critical since it is essential for determining the minimum amount of stirrups and the contribution of concrete to the shear strength of the beam. Most of the existing equations predicting the diagonal cracking strength of RC beams are based on experimental data. A powerful computational tool for analyzing experimental data is an artificial neural network (ANN). Its advantage over conventional methods for empirical modeling is that it does not require any functional form and it can be easily updated whenever additional data is available. An ANN model was developed for predicting the diagonal cracking strength of RC slender beams without stirrups. It is shown that the performance of the ANN model over the experimental data considered in this study is better than the performances of six design code equations and twelve equations proposed by various researchers. In addition, a parametric study was conducted to study the effects of various parameters on the diagonal cracking strength of RC slender beams without stirrups upon verifying the model.

Effect of plastic rotation on the concrete contribution to shear strength of RC beams

Aydemir, Cem,Aydemir, Muberra Eser,Arslan, Guray Techno-Press 2021 Advances in concrete construction Vol.11 No.6

This paper provides an analytical model to predict the concrete contribution to shear strength of reinforced concrete (RC) beams that fail in flexure. In the RC members subjected to cyclic loading, the stiffness and hysteretic energy dissipation decreases with diagonal web cracking in the plastic hinge region. The proposed method takes into account plastic rotation in the plastic hinge region by means of critical shear crack theory. To verify the concrete contribution to shear strength predicted by the proposed method, six normal- and high-strength RC beams having various shear span-to-effective depth ratios are tested under cyclic loading. The predictions by the proposed equation and various researchers' equations are compared to the test results. It is found that the proposed method is in good agreement with the test results.

Comparison of displacement capacity of reinforced concrete columns with seismic codes

Cansiz, Sinan,Aydemir, Cem,Arslan, Guray Techno-Press 2019 Advances in concrete construction Vol.8 No.4

The lateral displacement or drift may be the cause of the damage in the reinforced concrete (RC) columns under the seismic load. In many regulations, lateral displacement was limited according to the properties of columns. The design displacement limits may be represented indirectly through the material strain limits and the mechanical properties of columns. EUROCODE-8 and FEMA356 calculate displacement limits by taking into account the mechanical properties of columns. However, Turkey Building Earthquake Code (TBEC) determine displacement limits by taking into account the material strain limits. The aim of this study is to assess the seismic design codes for RC columns through an experimental study. The estimates of seismic design codes have been compared with the experimental results. It is observed that the lateral displacement capacities of columns estimated according to some seismic codes are not in agreement with the experimental results. Also, it is observed that TBEC is conservative in the context of the performance indicator of RC columns, compared to EUROCODE-8 and FEMA356. Moreover, in this study, plastic hinge length and effective stiffness of test elements were investigated.