TR Dizin İndeksli Yayınlar Koleksiyonu / TR Dizin Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/20.500.14365/4

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Citation - WoS: 1
Citation - Scopus: 1
About The Article Titled “a Different Scintigraphic Perspective On The Systolic Function Of The Left Ventricle-1” [“sol Ventrikül Sistolik Fonksiyonuna Sintigrafik Olarak Farklı Bir Bakış Açısı-1” Başlıklı Makale Hakkında]
(Galenos Publishing House, 2024) Taşçı, Cengiz
[No abstract available]
Citation - WoS: 2
Citation - Scopus: 2
Adrenomedullin Has No Effect on Segmental Bone Defect Healing but Increases Bone Mineral Density in Rat Model
(AVES, 2023) Kaymakoğlu, Mehmet; Ciftci, E.; Korkusuz, P.; Ozdemir, E.; Erden, M.E.; Turhan, E.
Objective: This study aimed to investigate the effect of adrenomedullin on the healing of the segmental bone defect in a rat model. Methods: Thirty-six Wistar rats were randomly divided into 6 groups based on follow-up periods and administered a dose of adreno-medullin hormone. In each group, bilaterally, a 2-mm bone defect was created at the diaphysis of the radius. Sodium chloride solution was administered to sham groups 3 times a week for 4 and 8 weeks intraperitoneally. Adrenomedullin was administered to the study groups 3 times a week: 15 μg—4 weeks, 15 μg—8 weeks, 30 μg—4 weeks, and 30 μg—8 weeks, respectively. After euthanasia, the segmental defects were evaluated by histomorphometric [new bone area (NBA)] and microtomographic [bone volume (BV), bone surface (BS), and bone mineral density (BMD)] analyses. Results: Although the 4-and 8-week 15 μg administered study groups had higher NBA values than the other study and control groups, the histomorphometric analysis did not reveal any statistical difference between the control and study groups regarding NBA (P >.05). In microtomographic analysis, BV was higher in the 15 μg 4-week group than 30 μg 4-week group (296.9 vs. 208.5, P =.003), and BS was lower in the 30 μg 4-week group than in the 4-week control group (695.5 vs. 1334.7, P =.005), but overall, no significant difference was found between the control and study groups (P >.05). Despite these minor differences in histomorphometric and microtomographic criteria indicating new bone formation, the BMD values of the 15 μg 8-week study group showed a significant increase compared with the control group (P =.001, respectively). Conclusion: Adrenomedullin positively affected BMD at 15 μg, but this study could not show healing in the segmental defect site at different dose regimens. Further studies are needed to assess its effects on bone tissue trauma. © 2023, AVES. All rights reserved.
Citation - WoS: 1
Citation - Scopus: 1
Aesthetic and Cultural Approach To the Change in the Making Techniques of Karagoz Figures
(Istanbul Univ, Research Inst Turkology, Dept Art History, 2021) Öngen Corsini, Duygu Ebru
Karagoz developed as a unique culture in Anatolian lands. Despite many controversies about how Karagoz came into existence, there is a consensus that it emerged in the 16th century. Figures, as cultural objects, have production methods and techniques interwoven with the doctrines of the past. Today, figure-making for different purposes, inherited from the past, is present in Karagoz figure art. The aesthetic reflections, technique, and material harmony of the figures for show purposes must carry the cultural essence of Karagoz. This study examines museum collections and exhibitions, interviews with Karagoz masters, and a data analysis from an academic perspective. Considering these factors, it becomes clear that the training of masters for figure-making art is significant. Long-term training organized by institutions will contribute to this art and might be beneficial for good examples to reach the audience. Transferring the figures to future generations while preserving their cultural essence, making them in a suitable technique, and aesthetic understanding synthesized with modern techniques; will also contribute to the survival of this art.
Citation - WoS: 2
Citation - Scopus: 3
An Analysis of Physical and Psychological Expectations of Earthquake Victims From Temporary Shelters: a Design Proposal
(Middle East Technical Univ, 2012) Yuksel, Belma; Hasirci, Deniz
This study analyzes physical and psychological expectations of earthquake victims from temporary shelters and presents a design proposal. Interviews were conducted with earthquake victims in the city of Kocaeli in Turkey, and needs were identified. Also, user survey results from previous studies that have been conducted after the August 17th earthquake in 1999 were used to establish the design requirements for a temporary housing unit. While lack of space and issues of crowding, noise, and hygiene were mentioned as the most important problems in temporary earthquake shelters, suggestions to improve them included consideration of psychology and privacy needs of victims. The need for a home and not just a shelter has been identified and design guidelines have been examined.
Citation - WoS: 14
Citation - Scopus: 12
Analysis of Risk Factors Affecting Mortality in Elderly Patients Operated on for Hip Fractures: a Retrospective Comparative Study
(Turkish Assoc Orthopaedics Traumatology, 2021) Biçen, Ahmet Çağdaş; Akdemir, Mehmet; Turken, Mehmet Aykut; Cekok, Kubra; Ekin, Ahmet; Turan, Ahmet Cemil
Objective: The aims of this study were (1) to investigate the effects of different demographic and perioperative modalities on mortality rates and (2) to compare mortality rates between different implants in elderly patients operated on for hip fractures. Methods: In this retrospective study, a total of 314 patients who were operated on for hip fractures were included study. Patients were then divided into four groups based in their implant types: long-stem cementless bipolar hemiarthroplasty (n = 124; 102 female, 22 male; mean age = 84.2 +/- 6.4 years), standard-stem cementless bipolar hemiarthroplasty (n = 74; 48 female, 26 male; mean age = 83.5 +/- 6.9 years), antegrade intertrochanteric nail (n = 61; 35 female, 26 male; mean age = 78.5 +/- 6.8 years), and total hip arthroplasty (n = 55; 34 female, 21 male; mean age = 72.5 +/- 4.3 years). Data including gender, age, duration from injury to surgery, American Society of Anesthesiologists (ASA) score, comorbidities, use of antiplatelet agents, Barthel Index of Activities of Daily Living, type of anesthesia, operation time, preoperative hemoglobin values, blood transfusions given, duration of hospital stay, complications, and type of fracture were recorded. Results: Overall, the mean follow-up was 36.5 (range = 0 - 107) months. The overall mortality rate was 53.2%. The median survival duration was 44.2 +/- 5 months (range = 34.3 - 54). Survival rates were found significantly different among the groups (P = 0.001). In the first three years postoperatively, the mortality rate was higher in the standard-stem bipolar hemiarthroplasty group, but in the long-term follow-up, the long-stem bipolar hemiarthroplasty group exhibited the higher mortality rates. It was observed that some parameters had statistically significant effects on the mortality rates. Male gender, higher age, lower hemoglobin values, increased number of blood transfusions, ASA scores >= 3, the existence of >= 3 comorbidities were found as main predictors of increased mortality rates. Conclusion: The results of this study have shown that age, gender, preoperative hemoglobin levels, ASA scores, and comorbidities are significant factors affecting mortality in elderly patients operated on for hip fractures. Long-stem cementless bipolar hemiarthroplasty appears to show similar rates of mortality with standard-stem cementless bipolar hemiarthroplasty.
BATIN BÖLGESİ ORGANLARININ MR GÖRÜNTÜLERİNDEN ÇOK AŞAMALI HİYERARŞİK SINIFLAMA İLE BÖLÜTLENMESİ
(2015) Kavur, Ali Emre; Dicle, Oğuz; Güzeliş, Cüneyt; Selver, M. Alper; Selvi, Eşref
Tıbbi görüntüleme ile anatomi hakkında ayrıntılı bilgi elde edinilebildiğinden, tanı amaçlı görüntüleme günümüzde birçok açıdan önem kazanmıştır. Görüntüleme cihazları tarafından sunulan verilerin fazlalığı ve çeşitliliği nedeniyle, tüm veri yerine görüntülerde sadece ilgilenilen dokunun belirlenerek ayrılması (Bölütlenmesi) sağlanabilir. Elcil yöntemler ile bölütleme yorucu, zaman alıcı ve deneyim gerektiren bir işlem olduğundan, otomatik yordamlara gereksinim duyulmaktadır. Geliştirilen yordamların klinik koşullarında kullanılabilmesi içinse yüksek başarıma sahip sonuçlar üretmeleri gerekmektedir. Manyetik Rezonans (MR) görüntülerinden batın bölgesindeki organlarının bölütlenmesi pek çok zorluk içeren bir uygulama alanıdır ve bu konudaki çalışmalar sınırlı sayıdadır. Batın bölgesinde yer alan, karaciğer, böbrekler, dalak, pankreas, safra kesesi gibi organların MR görüntüleri kullanılarak ileri seviye tıbbi analizi ve üç boyutlu incelenmesi pek çok tıbbi prosedür için mecburi olduğundan, bu çalışmada, ilgili organların bölütlenmesinde yukarıda belirtilen zorluklara karşı gürbüz, bölütlenecek organın özellikleri ve organların birbirleriyle olan ilişkilerini (konum vb.) göz önüne alan bir sistem geliştirilmiştir. Geliştirilen sistem farklı MR sekansları ile elde edilen görüntülere uygulanarak elde edilen sonuçlar tartışılmıştır.
Bioinformatics Based Drug Repurposing Approach for Breast and Gynecological Cancers: RECQL4/FAM13C Genes Address Common Hub Genes and Drugs
(Galenos Publ House, 2025) Duran, Gizem Ayna
Objective: The prevalence of breast cancer and gynaecological cancers is high, and these cancer types can occur consecutively as secondary cancers. The aim of our study is to determine the genes commonly expressed in these cancers and to identify the common hub genes and drug components. Materials and Methods: Gene intensity values of breast cancer, gynaecological cancers such as cervical, ovarian and endometrial cancers were used from the Gene Expression Omnibus database Affymetrix Human Genome U133 Plus 2.0 Array project. Using the linear modelling method included in the R LIMMA package, genes that differ between healthy individuals and cancer patients were identified. Hub genes were determined using cytoHubba in Cytoscape program. “ShinyGo 0.80” tool was used to determine the disease-specific biological KEGG pathways. Drug.MATADOR from the ShinyGo 0.80 tool was used to predict drug-target relationships. Results: The RecQ Like Helicase 4 and Family with Sequence Similarity 13 Member C genes were found to be similarly expressed in breast cancer and gynaecological cancers. Upon KEGG pathway analyses with hub genes, Drug.MATADOR analysis with hub genes related to cancer related pathways was performed. We have determined these gene/drug interactions: NBN (targeted by Hydroxyurea), EP300 (targeted by Acetylcarnitine) and MAPK14 (targeted by Salicylate and Dibutyryl cyclic AMP). Conclusion: The drugs associated with hub genes determined in our study are not routinely used in cancer treatment. Our study offers the opportunity to identify the target genes of drugs used in breast and gynaecological cancers with the drug repurposing approach.
Can E-Cigarettes Be the Source of Lead Toxicity
(AVES, 2025) Yılmaz, Seda; Kılınc, Oguz; Atik, Merve Demirci
Citation - WoS: 15
Citation - Scopus: 14
Changes on Hepatitis C Virus Genotype Distribution in Western Turkey: Evaluation of Twelve-Year Data
(Aves, 2020) Duran, Alev Cetin; Cetinkaya, Ozgul Kaya; Sayiner, Ayca Arzu; Seydaoglu, Gulsah; Ozkaratas, Emre; Abacioglu, Hakan
Background/Aims: Hepatitis C virus (HCV) prevalence is 1% in Turkey with genotype 1 being the predominant type traditionally. However unique geographical location of Turkey and increasing human migration in the region influences the epidemiology of the infection. The aim of this study was to determine the changes in distribution of HCV genotypes and risk factors. Materials and Methods: In this retrospective single-center study, HCV genotyping results of 558 patients were evaluated in between 2005 and 2016.Three different HCV genotyping assays were used during the 12-year study period;restriction fragment length polymorphism (RFLP), Abbott Real Time HCV Genotype II and Bosphore HCV genotyping kit. Results: The most prevalent HCV genotype was genotype 1 detected in 88.4% of the patients followed by genotype 3 (5.2%),genotype 4 (2.9%),genotype 2 (2.1%), mixed genotypes (1.1%) and genotype 5 (0.3%). Genotype 1a showed an increasing prevalence. There were 19 patients (3.4%) either of foreign nationalities or Turkish citizens living abroad. Genotype 3 was the most common type among these patients which 10.3% had intravenous drug use history. Syrian migrant population differed in terms of HCV genotypes. Genotype 5 detected in two Syrian patients, which is the first report of HCV type 5 in Western Turkey. Among the HCV genotype 4 infected patients, 31.3% were Syrians. Conclusion: Our study showed that although genotype 1b dominance continues, the distribution and prevalence of HCV genotypes are changing in our region mainly due to migration and increase in the frequency of patients with non-traditional risk factors such as intravenous drug use. Monitoring the epidemiology of HCV genotypes may provide guidance in treatment decisions.
A Compact Three-Rotor Vtol Development for Medical Drug Transfer
(2024) Çiçin, Kürşat; Kankaya, Ali; Yalçınkaya, Fatma; Orhan, Hediye; Türker, Sena; Keskin, İlknur; Efe, Enes
This work presents the development of a low-cost and low-power consumption vertical take-off and landing unmanned aerial vehicle (VTOL-UAV) with a simple and innovative design approach. The VTOL-UAV is capable of runway-independent flight and has the ability to carry payloads such as medical drug boxes. The hull volume of the UAV has been maximized to enhance its carrying capacity, while a three-rotor configuration has been implemented to simplify the design, reduce costs, extend flight time, and minimize weight. The wing-mounted rotors are strategically positioned in vertical and horizontal orientations to ensure stable flight during take-off, landing, and cruise phases. The wings are detachable, enabling rapid repairs in the event of accidents. Powered by an advanced flight controller, the VTOL-UAV is capable of autonomous flight, making it suitable for delivering supplies and medical provisions to remote, hazardous, or emergency areas. Moreover, the UAV has the capability to operate at higher altitudes, avoiding obstacles in urban transportation. Overall, this work demonstrates the feasibility of developing a cost-effective and efficient VTOL-UAV with a straightforward design approach for diverse applications, including medical delivery and urban transportation.
Citation - WoS: 16
Citation - Scopus: 19
Comparative Analysis of Multicriteria Decision Making Methods for Postgraduate Student Selection
(Ani Yayincilik, 2010) Altunok, Taner; Özpeynirci, Özgür; Kazancoglu, Yigit; Yilmaz, Recai
Problem Statement: The educational recourses available for postgraduate education are limited compared with the resources for undergraduate education. An academic advisor is required for each graduate student. The academic staff allocates an important portion of his/her time for graduate studies of his/her students. Since the number of academic staff is limited, the number of graduate students should be limited, too. While a large number of students may attend an undergraduate course, this may not be possible for some graduate courses, which are designed especially for small student groups. Hence, the selection of postgraduate students is an important problem. The postgraduate student selection problem can be defined as selecting a subset of students from the applicants for a postgraduate program. Naturally, this problem is a multi-criteria decision-making problem since each applicant has several attributes and these attributes should be considered simultaneously during the selection process. Purpose of Study: The purpose of this study is to compare the performance of different multi criteria decision-making methods developed for ranking alternatives for the postgraduate student selection problem. The best method will also be used in the student selection process for the Defense Sciences Institute of Turkish Military Academy. Methods: This paper discusses three multi-criteria decision making methods developed for ranking alternatives, namely Analytic Hierarchy Process (AHP), Weighted Product (WP) and the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). A performance measure is defined and the performance values of the methods are compared using real data gathered from the graduates of Defense Sciences Institute of Turkish Military Academy for illustration purposes. Findings and Results: According to the findings, AHP is the best of the three competitors. The ranking obtained by AHP is quite similar to the ranking of students with respect to their cumulative grade point average (CGPA) after their graduation from the program. Conclusions and Recommendations: Considering graduate student selection problem as a multicriteria decision-making problem is very important and enables universities to enroll graduate students with important attributes and a variety of strengths. This paper compares the performance of different multicriteria decision-making methods on graduate student selection problem using a single performance measure. A further study can be making such a comparison with multiple performance measures.
Citation - WoS: 1
Citation - Scopus: 1
Crime and Media: the World of ‘reality Show’ as a Moral Frame of Reference
(Milli Folklor Dergisi, 2017) Erol Isik, Nuran; Yaman, Burcu
Crime and transgression has become an important factor which is portrayed by the media outlets. The genre called crime reality show situated within the genre of reality show in the media in recent years has a special place in popular cultural world of meaning. Those who are accepted as protagonists, confessors, interrogators, victims and vigilantes are among the major actors in crime reality shows which function as constructing various different cultural and sociological frames of reference. The purpose of this article is to answer to the following questions: What does the crime reality show narrative tell us about contemporary Turkish culture? What are the implications of such a genre in terms of producing a televisual morality? What are the dynamics between socially irresponsible imagination and the idea of moral panic constructed via sensibility guided reasoning? In this paper, we argue that the crime reality show genre in Turkish television employs communicative strategies which are based on mediatization of morality as well as a new trend called prudentialism.
Demansın Davranışsal ve Psikolojik Belirtileri Bilgi Ölçeği’nin Türkçe Versiyonunun (DDPB-T) Geçerliliği ve Güvenilirliği: Bakıcılar Arasında Psikometrik Bir Değerlendirme
(Turkiye Sinir ve Ruh Sagligi dernegi, 2024) Var, Levent; Güllüoğlu, Halil; Uysal, Hasan Armağan; Poyraz, Turan; Başaran, Simay; Eşkut, Neslihan
Amaç
Citation - WoS: 10
Citation - Scopus: 10
Design and Development of Hybrid Forecasting Model Using Artificial Neural Networks and Arima Methods for Sustainable Energy Management Systems: a Case Study in Tobacco Industry
(Gazi Univ, Fac Engineering Architecture, 2020) Resat, Hamdi Giray
This study presents a design and development of hybrid forecasting model by using ARIMA and artificial neural networks for short-term energy forecasting processes in energy management systems. Proposed model is applied into a company operating in the tobacco products manufacturing industry and reliability of the model is tested by using real-life data set in illustrative cases. In line with the results obtained from ARIMA method, some of the factors affecting electricity consumption are taken into consideration as input data for artificial neural network model. After considering the correlation between solar energy generation, working hours, production quantities and past electricity consumption data, various number of neurons and different training algorithms are tested to design the optimal system for the company. The proposed hybrid model provides around 39.9% improvement compared to forecast data obtained by using only ARIMA model.
Citation - WoS: 1
Detection of Alzheimer's Dementia by Using Deep Time-Frequency Feature Extraction
(AVES, 2023) Karabiber Cura, Özlem; Türe, H. Sabiha; Akan, Aydin
Alzheimer's disease (AD), a neurological condition connected with aging, causes cognitive deterioration and has a substantial influence on a patient's daily activities. One of the most widely used clinical methods for examining how AD affects the brain is the electroencephalogram (EEG). Handcraft calculating descriptive features for machine learning algorithms requires time and frequently increases computational complexity. Deep networks provide a practical solution to feature extraction compared to handcraft feature extraction. The proposed work employs a time-frequency (TF) representation and a deep feature extraction-based approach to detect EEG segments in control subjects (CS) and AD patients. To create EEG segments'TF representations, high-resolution synchrosqueezing transform (SST) and traditional short-time Fourier transform (STFT) approaches are utilized. For deep feature extraction, SST and STFT magnitudes are used. The collected features are classified using a variety of classifiers to determine the EEG segments of CS and AD patients. In comparison to the SST method, the STFT-based deep feature extraction strategy produced improved classification accuracy between 79.56% and 92.96%.
Citation - WoS: 5
Citation - Scopus: 7
Detection of Olfactory Stimulus in Electroencephalogram Signals Using Machine and Deep Learning Methods
(Istanbul University, 2024) Akbuğday, Burak; Akbugday, S.P.; Sadikzade, R.; Akan, A.; Unal, S.
The investigation of olfactory stimuli has become more prominent in the context of neuromarketing research over the last couple of years. Although a few studies suggest that olfactory stimuli are linked with consumer behavior and can be observed in various ways, such as via electroencephalogram (EEG), a universal method for the detection of olfactory stimuli has not been established yet. In this study, 14-channel EEG signals acquired from participants while they were presented with 2 identical boxes, scented and unscented, were processed to extract several linear and nonlinear features. Two approaches are presented for the classification of scented and unscented cases: i) using machine learning (ML) methods utilizing extracted features; ii) using deep learning (DL) methods utilizing relative sub-band power topographic heat map images. Experimental results suggest that the olfactory stimulus can be successfully detected with up to 92% accuracy by the proposed method. Furthermore, it is shown that topographic heat maps can accurately depict the response of the brain to olfactory stimuli. © 2024 Istanbul University. All rights reserved.
Citation - WoS: 1
Citation - Scopus: 1
Distinguishability of a Source Function in a Time Fractional Inhomogeneous Parabolic Equation With Robin Boundary Condition
(Hacettepe Univ, Fac Sci, 2018) Özbilge Kahveci, Ebru; Demir, Ali
This article deals with the mathematical analysis of the inverse problem of identifying the distinguishability of input-output mappings in the linear time fractional inhomogeneous parabolic equation D(t)(alpha)u(x, t) = (k(x)u(x))(x) + F(x, t) 0 < alpha <= 1, with Robin boundary conditions u(0, t) = psi(0)(t), u(x)(1,t ) = gamma(u(1, t) - psi(1)(t)). By defining the input-output mappings Phi[.] : K -> C-1[0, T] and Psi[.] : K -> C[0, T] the inverse problem is reduced to the problem of their invertibility. Hence, the main purpose of this study is to investigate the distinguishability of the input-output mappings Phi[.] and Psi[.]. Moreover, the measured output data f(t) and h(t) can be determined analytically by a series representation, which implies that the input-output mappings Phi[.] : K -> C-1[0, T] and Psi[.] : K -> C[0, T] can be described explicitly.
Citation - WoS: 7
Citation - Scopus: 7
Effectiveness of a Program To Raise Awareness About Pneumococcal Vaccination Among Physicians and Patients With Chronic Respiratory Diseases: a Multicenter Cohort Study
(AVES, 2024) Karakurt, Z.; Yalnız, E.; Altın, S.; Oruç, Ö.; Uslu, Ö.; Veske, N.Ş.; Kılınç, O.; Sayıner, Abdullah
OBJECTIVE: There is a need to increase patient and clinician awareness on the effectiveness of pneumococcal vaccination in at-risk groups. The aim of the study was to evaluate the effect of reminders for physicians and patients using the vaccination tracking system created in the hospital information management system (HIMS) on the vaccination rate, and the effect of pneumococcal vaccination on pneumonia-related hospitalization and mortality over a 12-month period. MATERIAL AND METHODS: This prospective observational cohort study was undertaken during a 2-year period in 3 tertiary care cen-ters. Patients were followed up for 12 months following vaccination, and hospital admissions and mortality were recorded via HIMS. During the campaign, HIMS transmitted pneumococcal immunization reminder messages in accordance with guideline recommendations to physicians’ computers and patients’ mobile phones. Educational posters on pneumococcal vaccination were posted in outpatient clinics. Regular seminars on the evidence for pneumococcal vaccination were organized. All patients who were hospitalized during the follow-up period for chronic obstructive pulmonary disease (COPD), asthma, lung cancer, or pneumonia were analyzed in relation to their vaccination history regarding clinical outcomes. RESULTS: A total of 29 530 patients were included in the study. During the study period, the annual vaccination rate increased by 74.4% and reached 4.8% in 3 hospitals (P = .001). The rates were 3.9% in patients older than 65 years without comorbidities and 5.2% in those with COPD and asthma (P = .002). In pneumococcal vaccine recipients, pneumonia-related hospital mortality was lower (relative risk (RR) = 0.19, CI 0.09-0.35, P < .001). CONCLUSION: It is possible to raise the rate of pneumococcal vaccination through awareness campaigns. Individuals with COPD and asthma are more willing to receive pneumococcal vaccination. Among patients hospitalized for pneumonia, prior pneumococcal vaccination is associated with lower mortality. © Author(s).
Citation - WoS: 1
Effects of Flow Unsteadiness on the Transport of Bimodal Bed Material
(Turkish Chamber Civil Engineers, 2023) Bombar, Gokcen; Aksoy, Aysegul Ozgenc; Guney, Mehmet Sukru
The grain size distribution of the bed load was experimentally investigated under unsteady flow conditions with bimodal mixture of sand and gravel in a laboratory flume. Five various triangular hydrographs were generated. A clockwise behavior for the total bed load versus shear velocity was observed meaning that the bed load during rising limb was higher than that of falling limb. It was found that the percent finer at the plateau of bimodal sediment size distribution curve had higher values during the initial and final phases compared to those obtained during the peak time. At all plateaus, the percent finer values related to the hydrograph peak discharge were in the same order of magnitude with that of the bed material. The sand content of the transported bed material initially decreased, then maintained a constant value during a certain time interval and finally returned to its original value. The sand percent of the bed load decreased in the falling limb showing a counterclockwise loop and within the limits of the experimental campaign, the duration of the hydrograph did not affect the results considerably. Greater peak flow rate of the hydrograph resulted in greater hysteresis. The bimodality index was calculated for all transported sediment samples and it was revealed that its initial and final values were less than that of the bed material but it was approximately the same elsewhere. The 5% finer sediment amount was nearly equal during rising and falling limbs. It was revealed that D50 value of the bed load decreased in the rising limb showing a clockwise loop. The hysteresis was not considerably changed according to the hydrograph characteristics. The clockwise type hysteresis was also observed for the size group of D95. The lag increased as the peak flow rate increased. A strong relation was found between the dimensionless total bed load Wt* and the total work index Wk as well as Wk and the ratio WR/WF. The correlations between the dimensionless total bed load and the unsteadiness parameters P, and Pmod were very weak, whereas a quite high value of determination coefficient was obtained with the unsteadiness parameter Pgt, implying an appreciable interdependence.
Citation - WoS: 2
Citation - Scopus: 3
Effects of Vertebral Fusion on Levels of Pro-Inflammatory and Catabolic Mediators in a Rabbit Model of Intervertebral Disc Degeneration
(Turkish Assoc Orthopaedics Traumatology, 2021) Dumanlidag, Davut; Keles, Didem; Oktay, Gulgun; Kosay, Can
Objective: The aim of this study was to explore the alterations in levels of pro-inflammatory and catabolic mediators following vertebral fusion in a rabbit model of intervertebral disc degeneration. Methods: In this study, 24 female New Zealand albino rabbits (aged 4 to 5 months and weighing 3 to 3.5 kg) were used. All the animals were randomly categorized into four groups, and dorsal spinal exposure of all lumbar vertebrae was routinely performed in each group. While disc degeneration was created in groups B, C, and D, spinal fusion was added to disc degeneration in groups C and D. Disc degeneration was typically created by puncturing the discs with an 18-gauge needle under the guidance of C-arm imaging. Fusion was achieved with posterior/posterolateral decortication and iliac bone grafts. The rabbits in groups A, B, and C were euthanized, and the discs were removed in the first week after the surgery. The rabbits in Group D were sacrificed, and the discs were harvested at 5 weeks after the surgery. The levels of Interleukin (IL)-1 beta, IL-6, Nitric Oxide (NO), Matrix Metalloproteinase (MMP)-3, MMP-13, and Tissue Inhibitor of Metalloproteinases-1 (TIMP-1) in the discs were analyzed using enzyme-linked immunosorbent assay kits. Results: Significant increase was observed in the protein levels of both pro-inflammatory and catabolic mediators in disc degeneration groups (Group B, C, and D) compared to Group A. In the fusion groups (Group C and D), these increased mediators decreased, compared to non-fusion group (Group B), (IL1-beta P = 0.017, TIMP-1 P = 0.03, NO P = 0.03). However, there was no statistically significant difference in mediator levels between the short- and long-term fusion (Group C versus D). Conclusion: The results of this study have shown that a significant decrease in pro-inflammatory and catabolic mediators may be expected after vertebral fusion whereas there may be no significant difference between the first and fourth week of fusion surgery. These findings may contribute to clarifying the mechanism of action of vertebral fusion in the treatment of low back pain.

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