Rektörlüğe Bağlı Bölümler
https://hdl.handle.net/20.500.12587/8143
Other Units2024-03-28T15:15:39ZThe examination of performance characteristics of a beta‐type Stirling engine with a rhombic mechanism: The influence of various working fluids and displacer piston materials
https://hdl.handle.net/20.500.12587/18245
The examination of performance characteristics of a beta‐type Stirling engine with a rhombic mechanism: The influence of various working fluids and displacer piston materials
Derviş EROL
Fosil kökenli yakıtların rezervlerinin hızlı bir şekilde tüketilmesi, petrol fiyatlarındaki dalgalanmalar, küresel ısınma, çevre kirliliği, jeopolitik gerilimler ve enerji talebindeki artış gibi sebeplerden dolayı, yenilenebilir enerji kullanımının artırılması ve fosil yakıtların daha verimli kullanılması tüm dünyada son derece önemli bir konu haline gelmiştir. Ayrıca çevre kirliliğinin ciddi boyutlara ulaşması bilim insanlarını içten yanmalı motorlar için alternatif ve temiz enerji kaynakları araştırmaya yönlendirmiştir. Özellikle dizel motorlarda bazı katkı maddeleri ile emisyonların azaltılması büyük önem taşımaktadır. Dizel motorlarda alternatif yakıt çalışmalarında farklı alkol ve biodiesel yakıt harmanlarının kullanılması çevresel ve ekonomik açıdan çok önemlidir. Bu çalışmada diesel, biodisel ve farklı alkoller kullanılarak oluşturulan yakıt karışımlarının tek silindirli, sıkıştırma ile ateşlemeli bir motorda, fossil kökenli yakıtların yerine alternatif bir yakıt olarak kullanılabilirliğinin incelenmesi amaçlanmıştır.; Increasing the use of renewable energy and using fossil fuels more efficiently have become an extremely important issue all over the world due to reasons such as the rapid consumption of fossil fuel reserves, fluctuations in oil prices, global warming, environmental pollution, geopolitical tensions and an increase in energy demand. In addition, the serious environmental pollution has led scientists to search for alternative and clean energy sources for internal combustion engines. Especially in diesel engines, it is of great importance to reduce emissions with some additives. The use of different alcohol and biodiesel fuel blends in alternative fuel studies in diesel engines is very important in terms of environmental and economic aspects. In this study, it was aimed to investigate the usability of fuel mixtures formed by using diesel, biodiesel and different alcohols as an alternative fuel instead of fossil fuels in a single cylinder, compression ignition engine.
2021-01-01T00:00:00ZHiperprolaktineminin Total Oksidan, Total Antioksidan, Total Thiol ve Native Thiol Düzeyleri Üzerindeki Etkisinin İncelenmesi
https://hdl.handle.net/20.500.12587/18244
Hiperprolaktineminin Total Oksidan, Total Antioksidan, Total Thiol ve Native Thiol Düzeyleri Üzerindeki Etkisinin İncelenmesi
Nevin SAĞSÖZ
Aim: The aim of this study was to investigate the effects of hyperprolactinemia on total antioxidant levels (TAS), total oxidant levels (TOS), total thiol and native thiol levels. Background: Prolactin; it is a peptide hormone synthesized from the anterior pituitary by pituitary lactotrophs in both physiological and pathological conditions. Elevated prolactin (>30 ng/mL) is a common syndrome called "hyperprolactinemia". It affects both sexes. It is characterized by classical amenorrhea (in women) -- galactorrhea and hypogonadotropic hypogonadism (in both sexes) that cause infertility in both sexes. It is stated that prolactin is associated with functions of reducing cytosolic reactive oxygen species (ROS) and maintaining antioxidant capacity, apart from its known functions such as initiating milk secretion. ROS are produced by cells in normal metabolic and physiological processes. Oxygen is converted to water in mitochondria as a result of electron transport chain reactions. In this metabolic process, 2-3% of the oxygen in the mitochondria does not turn into water, but forms a source for the formation of radicals such as oxygen-derived superoxide, hydrogen peroxide and hydroxyl radical. ROS can cause harmful oxidative reactions in organisms that remove them by enzymatic and non-enzymatic antioxidative mechanisms. Under certain conditions, an increase in oxidants and a decrease in antioxidants cannot be prevented, and the oxidative/antioxidative balance shifts towards the oxidative state. As a result, oxidative stress develops, which plays a role in the formation of a large number of diseases. Although it is possible to measure the plasma concentrations of oxidant molecules separately, this is not feasible as these molecules can affect each other. Therefore, the total oxidant status (TOS) measurement, which reflects the overall oxidant status, has been developed. TAS measurement is similarly more informative than individual measurements of antioxidants. One of the important antioxidant molecules in the cell is thiol (thiol) groups. Intracellular thiols, including glutathione and thioredoxin, present in millimolar concentrations within cells, are essential for maintaining the highly reduced intracellular environment. Thiols also form an important component in the antioxidant defense of the cell. Thiol/disulfide homeostasis (TDH) is a marker of oxidative stress. Materials and Methods: This study will consist of approximately 30 hyperprolactinemia patients and 30 healthy volunteers who applied to the Kırıkkale University Medical Faculty Hospital Obstetrics and Gynecology clinic. Necessary diagnoses will be made by Dr. Nevin Sağsöz. In order to carry out the study, blood samples will be taken from all volunteers and their age, weight, height, etc. demographic characteristics such as galactorrhea and amenorrhea, menstrual patterns will be recorded. The correlation between the data obtained from the study and prolactin levels will also be examined. TAS and TOS analyzes will be made using the serum obtained from blood samples from volunteer individuals. TAS, TOS, native thiol and total thiol analyzes will be determined using the calorimetric measurement kits.
2021-01-01T00:00:00Zİn Vitro Ortamda Koç Testis Hücreleri ve Epididimal Spermatozoa Üzerine Bir Herbisit Olan Florasulamın Toksik Etkisi
https://hdl.handle.net/20.500.12587/18243
İn Vitro Ortamda Koç Testis Hücreleri ve Epididimal Spermatozoa Üzerine Bir Herbisit Olan Florasulamın Toksik Etkisi
Ömer VARIŞLI
Florasulam herbisit etkisine sahip bir zirai ilacıdır ve yeni nesil bir ilaç bileşeni olarak kullanımı yaygınlaşmaktadır. Bu çalışmanın amacı, florasulamın koç testis hücreleri ve spermatozoa üzerindeki in vitro etkisini araştırmaktır. Spermalar yerel bir mezbahadan elde edilen koç testislerinden sağlanacak. Farklı florasulan dozlarına (0-1000 µg), farklı inkübasyon sürelerinde (0, 2, 4, ve 6 saat) 37 °C su banyosunda maruz bırakılan spermatozoa, motilitesi, canlılık, akrozom bütünlüğü, mitokondrial memran potansiyeli ve apaptozis yönünden değerlendirilecek. Koç testis hücreleri yine yerel bir mezbahadan elde edilen sığır testislerinden izole edilecek. 1.0x104 hücre/kuyucuk ve 1.5x106 hücre/kuyucuk, 96 ve 12 bölmeli hücre kültür plaklarında 24 saat inkübe edilecektir. Daha sonra farklı konsantrasyonlarda (0 - 1000 μg / ml) florasulam 48 saat süreyle hücrelere uygulanacak. Sitotoksisite, ticari WST-1 kiti kullanılarak kolorimetrik bir yöntemle ölçülürken, hormon seviyeleri elektrokemilüminesans immünoassay ile ölçüleçek.; Florasulam has a herbicide effect and used in agriculture to control. Its use is becoming widespread as a new generation pesticide ingredient. The point of this study is to investigate the in vitro effect of florasulam on ram testicular cells and spermatozoa. The sperm will be collected from the ram testes obtained from a local slaughterhouse. Motility, viability, acrosome integrity and mitochondrial membrane potential (MMP) exposed to florasulan doses between (0--1000 µg), were evaluated at different incubation time (0, 2, 4, and 6 h) in 37 ℃ in water bath. The cells will be isolated from the bovine testes obtained from a local slaughterhouse. 1.0x104cell/well and 1.5x106 cell/well will be seeded in 96-well and 12-well culture and will be incubated for 24 h for attachment. After that, florasulam treatment at different concentrations (0 -- 1000 μg/ml) was applied to cells for 48 h. Cytotoxicity was measured with a colorimetric method using commercial WST-1 kit and hormone levels were measured by electrochemiluminescence immunoassay.
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2021-01-01T00:00:00ZVitreoretinal Hastalıkların Cerrahi Tedavisinde 25 Gauge Transkonjonktival (Sütürsüz) Vitrektomi İle Klasik Sütürlü Vitrektomi Cerrahi Sistemlerinin Karşılaştırılması
https://hdl.handle.net/20.500.12587/18242
Vitreoretinal Hastalıkların Cerrahi Tedavisinde 25 Gauge Transkonjonktival (Sütürsüz) Vitrektomi İle Klasik Sütürlü Vitrektomi Cerrahi Sistemlerinin Karşılaştırılması
Tevfik OĞUREL
In the 20 Gauge vitrectomy system, which is one of the modern vitreous surgery techniques in use today, sclerotomies entered into the eye must be closed with sutures at the end of the operation. The use of sutureless incision technique in phacoemulsification surgery has shortened the surgical trauma and operation time. With the same thought, a 25 Gauge transconjunctival vitrectomy system has been developed for sutureless vitrectomy surgery. With our prospective study, we aim to create a more appropriate treatment methodology in the surgical treatment of vitreoretinal diseases by comparing 25 Gauge transconjunctival (sutureless) vitrectomy and classical sutured vitrectomy surgical systems in terms of patient comfort, complication rates, length of hospital stay, and efficacy-cost. Within the scope of the research, 20 or 25 Gauge pars plana vitrectomy system will be applied to patients who apply to Kırıkkale University Faculty of Medicine, Department of Ophthalmology with vitreoretinal pathologies such as vitreous hemorrhage, macular epiretinal membrane, macular hole, vitreomacular traction syndrome, endophthalmitis, dislocation of lens fragments to the vitreous. Those using 20 G systems will be called group 1, and those using 25 G systems will be called group 2. A total of 50 patients, 25 patients in each group, will be included in the study. The patients to be included in group 1 and group 2 will be randomly selected, and the randomization will be made on the randomr.org website. Groups will be formed from consecutive cases matched for age and sex. The research will last 12 months.
2021-01-01T00:00:00Z