Central Sagittal Angle of the Sacrum as a New Risk Factor for Patients with Persistent Low Back Pain after Caesarean Section

Hizir Kazdal,Ayhan Kanat,Osman Ersagun Batcik,Bulent Ozdemir,Senol Senturk,Murat Yildirim,Leyla Kazancioglu,Ahmet Sen,Sule Batcik,Mehmet Sabri Balik 대한척추외과학회 2017 Asian Spine Journal Vol.11 No.5

Study Design: Retrospective. Purpose: This study investigated the possible association of persistent low back pain (LBP) with caesarean section (CS) under spinal anesthesia. Overview of Literature: Many women suffer from LBP after CS, which is commonly performed under spinal anesthesia. However, this type of LBP is poorly understood, and there is poor consensus regarding increased risk after spinal anesthesia. Methods: We examined two groups of patients who underwent cesarean delivery under spinal anesthesia. Group I included patients who presented to a neurosurgical clinic complaining of LBP for at least 6 months. Group II was a control group with patients without LBP. We analyzed clinical and sagittal angle parameters, including age, body mass index, parity, central sagittal angle of the sacrum (CSAS), and sacral slope (SS). Results: Fifty-three patients participated in this study: 23 (43.1%) in Group I and 30 (56.9%) in Group II. Non-parametric Mann–Whitney U-tests showed that age, parity, and CSAS significantly differed between the two groups at 6 months. Conclusions: Age, parity, and CSAS appear to be associated with increased risk for LBP after CS under spinal anesthesia. Future prospective studies on this subject may help validate our results.

Numerical studies on non-linearity of added resistance and ship motions of KVLCC2 in short and long waves

Hizir, Olgun,Kim, Mingyu,Turan, Osman,Day, Alexander,Incecik, Atilla,Lee, Yongwon The Society of Naval Architects of Korea 2019 International Journal of Naval Architecture and Oc Vol.11 No.1

In this study, numerical simulations for the prediction of added resistance for KVLCC2 with varying wave steepness are performed using a Computational Fluid Dynamics (CFD) method and a 3-D linear potential method, and then the non-linearities of added resistance and ship motions are investigated in regular short and long waves. Firstly, grid convergence tests in short and long waves are carried out to establish an optimal mesh system for CFD simulations. Secondly, numerical simulations are performed to predict ship added resistance and vertical motion responses in short and long waves and the results are verified using the available experimental data. Finally, the non-linearities of added resistance and ship motions with unsteady wave patterns in the time domain are investigated with the increase in wave steepness in both short and long waves. The present systematic study demonstrates that the numerical results have a reasonable agreement with the experimental data and emphasizes the non-linearity in the prediction of the added resistance and the ship motions with the increasing wave steepness in short and long waves.

Numerical studies on non-linearity of added resistance and ship motions of KVLCC2 in short and long waves

Olgun Hizir,Mingyu Kim,Osman Turan,Alexander Day,Atilla Incecik,Yongwon Lee 대한조선학회 2019 International Journal of Naval Architecture and Oc Vol.11 No.1

In this study, numerical simulations for the prediction of added resistance for KVLCC2 with varying wave steepness are performed using a Computational Fluid Dynamics (CFD) method and a 3-D linear potential method, and then the non-linearities of added resistance and ship motions are investigated in regular short and long waves. Firstly, grid convergence tests in short and long waves are carried out to establish an optimal mesh system for CFD simulations. Secondly, numerical simulations are performed to predict ship added resistance and vertical motion responses in short and long waves and the results are verified using the available experimental data. Finally, the non-linearities of added resistance and ship motions with unsteady wave patterns in the time domain are investigated with the increase in wave steepness in both short and long waves. The present systematic study demonstrates that the numerical results have a reasonable agreement with the experimental data and emphasizes the non-linearity in the prediction of the added resistance and the ship motions with the increasing wave steepness in short and long waves.

Environmental Radioactivity and High Incidence Rates of Stomach and Esophagus Cancer in the Van Lake Region: A Causal Relationship?

Akan, Zafer,Baskurt, Busranur,Asliyuksek, Hizir,Kam, Erol,Yilmaz, Ahmet,Yuksel, Mehmet Bilgehan,Biyik, Recep,Esen, Ramazan,Koca, Dogan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.1

This study examined the incidence rates of cancer cases (averages for 2006-2010) and relationships with environmental radioactivity levels. Soil and water samples were collected from provincial and district centers of Van city and the outdoor gamma doses were determined using a portable gamma scintillation detector. Gross alpha and beta, (226)Ra, (232)Th, and (40)K activities were measured in both tap water and soil samples. Although high rates of stomach and esophagus cancers have been reported previously in Van the underlying reasons have not hitherto been defined. Incidences of cancers were highest in the Gurpmar (326.0) and Ozalp (377.1) counties (p<0.001). As to the results of the gross alpha and gross beta radioactivity measurements in the drinking water, these two counties also had high beta radionuclide levels: Gurpmar ($140mBq/dm^3$) and Ozalp ($206mBq/dm^3$). Even if within the normal range, a relation between the higher rate of the incidence of stomach and esophagus cancers with that of the higher rate of beta radionuclide activity was clear. On Spearman correlation analysis, the relation between higher beta radionuclide levels and cancer incidence was found to be statistically significant (p<0.01). According to the results of the analysis, Van residents receive an average 1.86 mSv/y annual dose from outdoor gamma radiation, ingestion of radionuclides in the drinking water, and indoor $^{222}Rn$ activity. Moreover, gross alpha and beta activities were found to be extremely high in all of the lakes around the city of Van, Turkey. Further investigations with long-term detailed environmental radiation measurements are needed regarding the relationship between cancer cases and environmental radioactivity in the city of Van.

Introducing a New Risk Factor for Lumbar Disc Herniation in Females : Vertical Angle of the Sacral Curvature

Kanat, Ayhan,Yazar, Ugur,Kazdal, Hizir,Sonmez, Osman Fikret The Korean Neurosurgical Society 2012 Journal of Korean neurosurgical society Vol.52 No.5

Objective : To characterize the importance of the vertical angle of the sacral curvature (VASC) in lumbar disc herniations. Methods : Morphological data derived from lumbar sagittal MRI imaging. The statistical significance of the findings are discussed. The angles of 60 female patients with lumbar disc herniations (LDH) were compared with the 34 female patients without LDH. Results : 128 of the 185 patients met our inclusion criteria. The vertical angle of sacral curvature is statistically significantly bigger in females with lumbar disc herniations when compared to subjects in control group, 28.32 and 25.4, respectively. (p=0.034<0.05). Same difference was not seen in males. Conclusion : The vertical angle of sagittal sacral curvature may be another risk factor in females with lumbar disc herniations.

Analysis of Postural Stability and Daily Energy Expenditure to Manage Tumor Patients’ Functional Expectation

Emrah Caliskan,Evrim Karadag Saygi,Zeynep Kardelen Gencer,Hizir Kurtel,Bulent Erol 대한정형외과학회 2018 Clinics in Orthopedic Surgery Vol.10 No.4

Background: Advances in surgical techniques, implant technology, radiotherapy, and chemotherapy have increased the recovery chances of patients with bone sarcomas. Accordingly, patients’ expectations on life quality have also increased, highlighting the importance of objective evaluation of the functional results of reconstruction. Methods: Thirteen patients with distal femoral endoprosthesis, who had been followed for an average of 2.9 years were evaluated. Postural stability, daily energy expenditure, muscle power, and range of motion were the four parameters analyzed in this study. The Musculoskeletal Tumor Society (MSTS) score and Toronto Extremity Salvage Score (TESS) were used to assess postoperative function and examine correlations with other parameters. Results: Patients had sedentary activities in 84% of their daily lives. They exhibited a slower speed in the walk across test and a higher sway velocity in the sit-to-stand test (p = 0.005). MSTS scores were significantly correlated with the daily energy expenditure and walking speed. Conclusions: Objective functional results acquired from various clinics will provide significant data to compare reconstruction techniques, rehabilitation protocols, and surgical techniques. In this way, it will be possible to satisfy the expectations of patients that increase in relation to enhanced recovery.