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Öğe Correlates of benefit from induction chemotherapy before radiotherapy in non-small cell lung cancer (NSCLC): A meta-analytical approach with meta-regression analysis(AMER SOC CLINICAL ONCOLOGY, 2008) Bozcuk, H. S.; Ozdogan, M.; Artac, M.; Yildiz, M.[Abstract not Available]Öğe Determination of excited-state ionization Potentials for lithium-like sequence using weakest bound electron potential model theory(POLISH ACAD SCIENCES INST PHYSICS, 2007) Celik, G.; Yildiz, M.; Kilic, H. S.In this work, the theoretical calculation of excited-state ionization potentials for Is(2)2p(2)P(1/2), 1s(2)3s(2)S(1/2), 1s(2)3d(2)D(1/2), 1s(2)4s(2)S(1/2), 1s(2)4p(2)P(1/2), and 1s(2)4d(2)D(1/2) iso-spectrum series of lithium-like elements were carried out using a weakest bound electron potential model theory for nuclear charges from Z = 3 to Z = 18. The Breit-Pauli approximation was used for relativistic contributions. The obtained values are compared with the experimental results from literature. The overall agreement between data obtained in this work and experimental data from literature can appear to be quite good being generally within 0.1% of experimental values.Öğe Effect of freezing and thawing on strength and permeability of lime-stabilized clays(SHARIF UNIV TECHNOLOGY, 2012) Yildiz, M.; Soganci, A. S.In this study, the effect of freezing and thawing on the strength and permeability of two clayey soils (high and low plasticity), which had been stabilized with lime, were investigated. Before and after stabilization, the permeability and strength of the specimens were determined with various freeze-thaw cycles. Results of this study indicated that for both clays, 6% lime addition increased the hydraulic conductivity of the specimens 1000 times. However, the hydraulic conductivity of clay with 6% lime increased 10-20 times after only 3 freeze-thaw cycles. The results of strength tests exhibited different trends. The strength of stabilized high plasticity clay increased approximately 15 times at the end of 28 day curing, whereas the strength of stabilized low plasticity clay increased about 3 times only. The strength of both stabilized clays decreased 10-15% at the end of the freeze-thaw cycles. (C) 2012 Sharif University of Technology. Production and hosting by Elsevier B.V. All rights reserved.Öğe Elderly trauma: the two years experience of a University-affiliated Emergency Department(VERDUCI PUBLISHER, 2012) Yildiz, M.; Bozdemir, M. N.; Kilicaslan, I.; Atescelik, M.; Gurbuz, S.; Mutlu, B.; Onur, M. R.Objective: The elderly population is steadily increasing in the modern world. The aging of the population has led to an increase in geriatric trauma. Elderly trauma patients present unique challenges and face more significant obstacles in recovery compared to younger patients. This study is designed to determine the epidemiologic data of trauma in elderly patients and to contribute to the national trauma database. Materials and Methods: We prospectively collected the data of trauma patients, aged 65 and older, presenting to our Emergency Department. Patients' data, including demographic data, diagnosis, prognosis, trauma scores [Glasgow Coma Scale (GCS), Injury Severity Score (ISS)], mortality, body regions of injury and outcomes were analyzed. Results: During the study period, 407 patients, of whom 63.9% were males and 36.1% females, were admitted to our Emergency Department. The mean age of the patients was 73.14 +/- 7.14 years. Falls (59%) accounted for the most common cause of injury. The mean GCS and mean ISS were 14.39 and 10.69, respectively. Trauma to extremities was the most frequent body region of injury (56.3%). A total of 149 patients were hospitalized. The mean hospital length of stay was 11.07 +/- 14 days. The mortality rate was found to be 6.4%. Head trauma was the most common cause in mortality. Conclusions: The risk of trauma in the elderly population is higher. As a result of the decrease in physiological reserve and lack of adaptation to trauma, elderly trauma patients require more aggressive management and a multidisciplinary approach. Further studies are needed for data of elderly trauma patients.Öğe Electric dipole radiative lifetimes for neutral boron atom(INDIAN ASSOC CULTIVATION SCIENCE, 2013) Yildiz, M.; Gokce, Y.; Celik, G.We have determined the radiative lifetimes of excited states in atomic boron using weakest bound electron potential model theory. For determining relevant parameters needed for calculation of lifetimes, we have employed numerical non-relativistic Hartree-Fock wave functions for expectation values of radius. The necessary energy values have been taken from experimental energy data from National Institute of Standards and Technology. The calculated lifetimes have been compared with available results.Öğe Improvement of the strength of soils which comprises granular pumice by injection of cement under low pressure(ELSEVIER SCIENCE BV, 2015) Yildiz, M.; Soganci, A. S.In this study, improvement of granular pumice soils strength by injection method in Nevsehir City (Turkey) was investigated. In the first phase of the study, the geotechnical properties of granular pumice soils were investigated. The specific density, dry unit weight and water absorption value increased with the decrease of grain size. Thus, it can be seen that the bearing capacity of pumice varies depending on the grain size. In the second level, changes in strength of unconfined compression of injected pumice samples were analysed. The samples taken from the field were prepared to 35, 65 and 85% density, relatively. Pressure of 100 kPa and water/cement ratio of 1.0 was applied to these test samples and the samples were allowed to be cured for a period of 7 and 28 days. The results of the study showed that injected pumice soil reached its maximum strength value with 35% relative density and reached its minimum value with 85% relative density. At the end of 28 days curing period, injected pumice soils prepared with 85% relative density have an equivalent strength to C8 concrete class, and grouted pumice soils prepared with 35% relative density have an equivalent strength to C12 concrete class. (C) 2015 Sharif University of Technology. All rights reserved.Öğe Influence of Acetic Acid on Structural Change and Shear Strength of Clays(Springer International Publishing Ag, 2012) Olgun, M.; Yildiz, M.This paper presents shear strength test results and structural changes in clay soils with acetic acid. Two different clay soils were used, kaolinite and another containing montmorillonite with a mixed mineralogy, while pure water and various contents of acetic acid (20%, 40%, 60% and 80%) were used as pore fluids. Clay-pore fluid slurries prepared with a water content of twice the liquid limit of each acetic acid content were consolidated under a 100 kPa pre-consolidation pressure. Direct shear tests were conducted on samples taken from pre-consolidated mixtures in order to determine changes in shear strength. Additionally, optical microscope images and scanning electron photomicrographs were obtained in order to observe structural changes under the influence of acetic acid. According to the experimental results, significant increases occurred in peak shear strength and shear strength parameter values in both clays in parallel with increasing acetic acid content. These increases were higher in the clay with montmorillonite; in particular, there were substantial changes in the internal friction angle. Increasing liquid limit values with increasing acetic acid contents in kaolinite resulted in a substantial decrease in the other clay. The optical microscope images and scanning electron photomicrographs indicated that lumpy formations occurred in both clays with the addition of acetic acid, and their structures began to resemble that of a silt and fine sand form.Öğe Model based and experimental investigation of respiratory effect on the HRV power spectrum(IOP PUBLISHING LTD, 2006) Yildiz, M.; Ider, Y. Z.The role of respiration in the genesis of heart rate variability ( HRV) has been the subject matter of many experimental and modeling studies. It is widely accepted that the high frequency ( HF) peak of a HRV power spectrum, which is centered at the average respiratory frequency, is caused by mechanisms activated by respiration. On the other hand, there is a debate on the possible role of respiration in the genesis of the low frequency ( LF) peak which is usually centered around 0.1 Hz. In this study, a comprehensive cardiorespiratory interaction model is used to test various hypotheses regarding the role of respiration in the LF peak of HRV. In this model, chest and abdomen circumference signals and lung volume signal are used as respiratory inputs. Simulations are made for periodic, spontaneous and slightly irregular respiratory patterns, and it is observed that the more low frequency ( LF) power there in the respiratory signals, the more LF power there in the model-predicted HRV. Experiments on nine volunteers are also performed for the same respiratory patterns and similar results are observed. Furthermore, the actual measured respiratory signals are input to the model and the model predicted and the actual HRVs are compared both in time domain and also with respect to their power spectra. It is concluded in general that respiration not only is the major contributor to the genesis of the HF peak in the HRV power spectrum, but also plays an important role in the genesis of its LF peak. Thus, the LF/HF ratio, which is used to assess sympathovagal balance, cannot be correctly utilized in the absence of simultaneous monitoring of respiration during an HRV test.Öğe Narrowing of airway caused by ingestion of methyl ethyl ketone peroxide(SAGE PUBLICATIONS LTD, 2011) Bozdemir, M. N.; Yildiz, M.; Seyhanli, E. S.; Gurbuz, S.; Kilicaslan, I.; Karlidag, T.Although ingestion of methyl ethyl ketone peroxide (MEKP) is rare, it carries a high risk of morbidity and mortality. This paper reports the first such case from Turkey in which a 70-year-old man unintentionally ingested MEKP in his kitchen. The patient was brought into the emergency department (ED) within I hour of ingestion, with the symptoms of sore throat, shortness of breath, nausea and vomiting. Visual examination of the oropharynx revealed minor burns and uvular edema. A laryngoscope examination performed in the ED showed superficial mucosal injury with edema of the oropharynx, uvula, posterior pharynx, epiglottis, arytenoids and vocal cords. Lateral cervical radiography revealed a narrowing of airway due to a thickened epiglottis. After the diagnostic evaluation was completed, the patient was admitted to the gastroenterology intensive care unit for monitoring of adverse reactions. During follow-up, the patient made an uneventful recovery. Ingestion of MEKP generally results from accidental ingestion from a container. Therefore, these containers should be kept in safe places. In addition, the priority following the ingestion of MEKP should be given to maintain open and adequate airway in the ED.Öğe Poisoning from wild mushrooms in Eastern Anatolia region: analyses of 5 years(SAGE PUBLICATIONS LTD, 2007) Durukan, P.; Yildiz, M.; Cevik, Y.; Ikizceli, I.; Kavalci, C.; Celebi, S.The objective of this study was to describe the demographic and clinical features of patients who were admitted to the emergency department (ED) due to wild mushroom poisoning and to point the importance of mushroom poisonings in our area. This study was performed by examining the files of wild mushroom poisoning patients who were admitted to the ED of Firat University, Faculty of Medicine, between January 2000 and June 2004, retrospectively. Patients :16 years of age were included in the study. The frequency of wild mushroom poisoning, age and sex of the patients, season, place of the residence, laboratory findings, treatment and outcome of the patients were investigated. During the study period, 64 patients with wild mushroom poisoning were admitted to the ED. From 64 overall patients, 25 (39.1%) were males. The most common complaints during the admission were nausea, vomiting and abdominal discomfort. The duration of hospitalization was two (range 1-4 days) days. No death was observed. Severity of mushroom poisoning depends on the type of mushroom eaten, the time lag between the poisoning and admission to the hospital, and the rapid and correct treatment given to the patient either in the ambulance or at health centre.Öğe QT dispersion in carbon monoxide poisoning(VERDUCI PUBLISHER, 2012) Atescelik, M.; Bozdemir, M. N.; Yildiz, M.; Gurbuz, S.; Ayranci, M.; Goktekin, M. C.; Kobat, M. A.Background: Carbon monoxide (CO) poisoning are serious health problems, and effect of reducing the blood's oxygen carrying capacity. Deaths due to CO poisoning are mostly related to myocardial injury and central nervous system pathologies. Aim: The objective of this study was to determine the relationship between carbon monoxide intoxication, QT dispersion, and cardiac markers. Materials and Methods: Patients with possible CO intoxication symptoms were evaluated to be eligible for the study. Patients' demographic data, carboxyhemoglobin levels, cardiac markers and QT interval measurements were recorded to the study form. Results: A total of 127 patients (79 CO intoxicated and 48 controls) were included into the study with a mean age of 38.6 +/- 14.1 years and 62.2% of them were female. Average levels of patient's carboxyhemoglobin were 21.3 +/- 9. OT dispersion (39.0 +/- 10.8 vs 24.4 +/- 6.2; p < 0,001) and corrected QT dispersion (46.2 +/- 14.7 vs 25.3 +/- 6.2; p < 0.001) were longer than the control group. Both QT dispersion (39.0 I 10.8 vs 23.6 +/- 7.0; p < 0.001) or corrected QT dispersion (46.2 +/- 14.7 vs 27.1 +/- 8.7; p < 0.001) were also decreased after one week later from the admission. Conclusion: Carbon monoxide intoxication is related to increased OT dispersion. Emergency physicians should measure QT dispersion in CO intoxicated patients in order to predict the electrical instability in myocardium and future adverse events.Öğe Radiative Lifetimes of Rydberg States in Neutral Gallium(POLISH ACAD SCIENCES INST PHYSICS, 2009) Yildiz, M.; Celik, G.; Kilic, H. S.Radiative lifetimes were calculated using weakest bound electron potential model theory for 4s(2) ns S-2(1/2) (n >= 7), 4s(2) np P-2(1/2)0 (n >= 5), 4s(2) np P-2(3/2)0 (n >= 6), 4s(2) nd D-2(3/2)0 (n >= 6), 4s(2) nd D-2(5/2)0 (n >= 6) series in neutral gallium. The use of the quantum defect theory and Martin's expressions allowed us to supply lifetime values along by means of the series above. The results obtained in this work presented good agreement with theoretical and experimental values. Moreover, some lifetime values not existing in the literature for highly excited Rydberg states in gallium atom were obtained using this method.
