Okan Üniversitesi / Okan University

Permanent URI for this communityhttps://hdl.handle.net/20.500.14517/1

Browse

Now showing 1 - 20 of 527

Citation Count: 5
4/3 problem, Poynting theorem, and electromagnetic energy-momentum tensor
(Canadian Science Publishing, 2015) Kholmetskii, Alexander L.; Missevitch, Oleg V.; Yarman, Tolga; Enerji Sistemleri Mühendisliği / Energy Systems Engineering
We show that the familiar 4/3 problem originates from the incorrect determination of the momentum of the electromagnetic field generated by an isolated charged particle, which results from an incorrect application of the Poynting theorem to the field. To demonstrate this, we consider a macroscopic problem: splitting a charged oil droplet into two identical smaller droplets in the rest frame K of the original droplet, and in another inertial frame K' moving with respect to K with some constant velocity, and arrive at a physically senseless solution in the framework of the standard approach. To solve this problem in a correct way, we suggest a modified Poynting theorem for an isolated charge and recalculate the momentum of the electromagnetic field of this charge, which yields the usual relativistic relationship between the field energy and momentum. Our approach is not at odds with the idea about "Poincare stresses"; however, in contrast to the standard method, it provides a usual relationship between the "Poincare stress-energy" and the associated momentum stress component. Finally, the continuity equation in four-dimensional form for the case of isolated moving charge is also proposed, which completely resolves the 4/3 problem.
Citation Count: 1
ABSTRACT CAPACITY OF REGIONS AND COMPACT EMBEDDING WITH APPLICATIONS
(Springer, 2011) Shakhmurov, Veli
The weighted Sobolev-Lions type spaces W-p,gamma(l) (Omega; E) boolean AND L-p,L-gamma (Omega; E-0) are studied, where E-0, E are two Banach spaces and E-0 is continuously and densely embedded on E. A new concept of capacity of region Omega is an element of R-n in Wp,gamma(l)(Omega; E-0, E) is introduced. Several conditions in terms of capacity of region Omega and interpolations of E-0 and E are found such that ensure the continuity and compactness of embedding operators. In, particular, the most regular class of interpolation spaces E-alpha between E-0 and E, depending of alpha and l, are found such that mixed differential operators D-alpha are bounded and compact from W-p,gamma(l)(Omega; E-0, E) to E-alpha-valued L-p,L-gamma spaces. In applications, the maximal regularity for differential-operator equations with parameters are studied.
Citation Count: 5
The acute effects of different intensity whole-body vibration exposure on muscle tone and strength of the lower legs, and hamstring flexibility: A pilot study
(Human Kinetics Publishers Inc., 2021) Saldiran,T.; Atici,E.; Rezaei,D.A.; Öztürk,Ö.; Uslu,B.; Özcan,B.A.; Okudan,B.; Fizyoterapi ve Rehabilitasyon / Physiotherapy and Rehabilitation
Context: The research on the change in properties of the lower leg muscles by different intensity sinusoidal vertical whole-body vibration (SV-WBV) exposures has not yet been investigated. Objective: The purpose of this study was to determine effect of a 20-minute different intensity SV-WBV application to the ankle plantar flexor and dorsiflexor muscles properties and hamstring flexibility. Design: Prospective preintervention-postintervention design. Setting: Physiotherapy department. Participants: A total of 50 recreationally active college-aged individuals with no history of a lower leg injury volunteered. Interventions: The SV-WBV was applied throughout the session with an amplitude of 2 to 4 mm and a frequency of 25 Hz in moderate-intensity vibration group and 40 Hz in a vigorous-intensity vibration group. Main Outcome Measures: The gastrocnemius and tibialis anterior muscle tone was assessed with MyotonPRO, and the strength evaluation was made on the same lower leg muscles using hand-held dynamometer. The sit and reach test was used for the lower leg flexibility evaluation. Results: The gastrocnemius muscle tone decreased on the right side (d=0.643, P=.01) and increased on the left (d = 0.593, P=.04) when vigorous-intensity vibration was applied. Bilateral gastrocnemius muscle strength did not change in both groups (P > .05). Without differences between groups, bilateral tibialis anterior muscle strength increased in both groups (P < .01). Bilateral gastrocnemius and tibialis anterior muscle tone did not change in the moderate-intensity vibration group (P > .05). Flexibility increased in both groups (P < .01); however, there was no statistically significant difference between the groups (d = 0.169, P = .55). Conclusions: According to study results, if SV-WBV is to be used in hamstring flexibility or ankle dorsiflexor muscle strengthening, both vibration exposures should be preferred. Different vibration programs could be proposed to increase ankle plantar flexor muscle strength in the acute results. Vigorous-intensity vibration exposure is effective in altering ankle plantar flexor muscle tone, but it is important to be aware of the differences between the lower legs. © 2021 Human Kinetics, Inc.
Citation Count: 0
Acute spinal epidural hematoma: A case report and review of the literature
(Turkish Assoc Trauma Emergency Surgery, 2020) Akar, Ezgi; Ogrenci, Ahmet; Koban, Orkun; Yilmaz, Mesut; Dalbayrak, Sedat
Spinal epidural hematoma (SEH) is a rare but a significant cause of spinal cord compression and neurologic deficits. Its etiology is usually unknown and requires emergency intervention. The present study aims to review the clinical significance, treatment strategies and clinical outcomes of traumatic SEH with a rare case presentation. Our patient was a 42-year-old female who presented with back pain and loss of sensation and strength in the legs. The patient did not have any disease and did not use anticoagulant drugs. The patient developed numbness in her legs half an hour after having a traditional back walking massage due to occasional back pain. She was paraplegic and anesthetic when seen in our clinic. Thoracic computed tomography (CT) and magnetic resonance imaging (MRI) revealed posterior epidural hemorrhage at Th3-Th4 levels. In the 12th hour, the hematoma was evacuated by an emergency decompressive hemilaminectomy. At the postoperative 24th hour, the patient had symptomatic improvement, and in the sixth month, the patient was mobilized with support. SEH is a rare condition that should be considered in patients with sudden onset of back pain and extremity weakness. Although the gold standard diagnostic tool is MRI, CT is often sufficient to avoid delayed surgery. Immediate surgical decompression (laminectomy/hemilaminectomy) should be performed in cases diagnosed with SEH with neurological deficits.
Citation Count: 101
Adaptation, validity, and reliability of the metacognition questionnaire-30 for the Turkish population, and its relationship to anxiety and obsessive-compulsive symptoms
(Turkiye Sinir ve Ruh Sagligi dernegi, 2008) Tosun, Ahmet; Irak, Metehan
Objective: The present study aimed to evaluate the psychometric properties of the short form of the Metacognition Questionnaire (MCQ-30) in a population of Turkish university students. The metacognitions questionnaire (MCQ) measures individual differences in a selection of metacognitive beliefs, judgments, and monitoring tendencies considered important in the metacognitive model of psychological disorders. Method: The study included 850 university students from 15 Turkish universities. Mean age age of the participants was 21.22 years, 282 (33.17%) were female, and 558 (66.82%) were male. Results: Construct validity was evaluated by exploratory and confirmatory factor analysis (CIA). Exploratory factor analysis revealed that the Turkish version of MCQ-30 has 5 components, which is some factor structure as the original form. In addition, the fit indices of CIA suggested an acceptable fit to a 5-factor model consistent with the original MCQ-30. The Turkish MCQ-30 showed acceptable to good test-retest reliability, internal consistency, and convergent validity. Significant positive relationships between the subscales of MCQ-30 and measures of anxiety and obsessive-compulsive symptoms provided further support for the convergent validity of the Turkish version. Moreover significant negative correlations were observed between age and the MCQ-30 subscales, and the effect of gender was significant on some of the subscales. Conclusion: The psychometric properties of the Turkish version of MCQ-30 showed that the instrument is a valuable additional tool for the assessment of metacognition in Turkey.
Citation Count: 0
Addendum to Spinal Schwannomatosis: Case Report of a Rare Condition
(Turkish Neurosurgical Soc, 2017) Hakan, Tayfun; Celikoglu, Erhan; Aker, Fugen; Barisik, Nagehan
[No Abstract Available]
Citation Count: 9
Adherence to guideline-directed medical and device Therapy in outpAtients with heart failure with reduced ejection fraction: The ATA study
(Turkish Soc Cardiology, 2020) Kocabas, Umut; Kivrak, Tarik; Oztekin, Gulsum Meral Yilmaz; Tanik, Veysel Ozan; Ozdemir, Ibrahim Halil; Kaya, Ersin; Pehlivanoglu, Seckin
Objective: Despite recommendations from heart failure guidelines on the use of pharmacologic and device therapy in patients with heart failure with reduced ejection fraction (HFrEF), important inconsistencies in guideline adherence persist in practice. The aim of this study was to assess adherence to guideline-directed medical and device therapy for the treatment of patients with chronic HFrEF (left ventricular ejection fraction <= 40%). Methods: The Adherence to guideline-directed medical and device Therapy in outpAtients with HFrEF (ATA) study is a prospective, multicenter, observational study conducted in 24 centers from January 2019 to June 2019. Results: The study included 1462 outpatients (male: 70.1%, mean age: 67 +/- 11 years, mean LVEF: 30%+/- 6%) with chronic HFrEF. Renin-angiotensin system (RAS) inhibitors, beta-blockers, mineralocorticoid receptor antagonists (MRAs), and ivabradin were used in 78.2%, 90.2%, 55.4%, and 12.1% of patients, respectively. The proportion of patients receiving target doses of medical treatments was 24.6% for RAS inhibitors, 9.9% for beta-blockers, and 10.5% for MRAs. Among patients who met the criteria for implantable cardioverter-defibrillator (ICD) and cardiac resynchronization therapy (CRT), only 16.9% of patients received an ICD (167 of 983) and 34% (95 of 279) of patients underwent CRT (95 of 279). Conclusion: The ATA study shows that most HFrEF outpatients receive RAS inhibitors and beta-blockers but not MRAs or ivabradin when the medical reasons for nonuse, such as drug intolerance or contraindications, are taken into account. In addition, most eligible patients with HFrEF do not receive target doses of pharmacological treatments or guideline-recommended device therapy.
Citation Count: 0
Advanced Data Mining Techniques
(informs, 2009) Ozgen, Arzum Eser
[No Abstract Available]
Citation Count: 8
Airborne pathogen projection during ophthalmic examination
(Springer, 2020) Bostanci Ceran, Basak; Karakoc, Alp; Taciroglu, Ertugrul
Purpose Microscale droplets act as coronaviruses (CoV) carriers in the air when released from an infected person and may infect others during close contact such as ophthalmic examination. The main objective of the present work is to demonstrate how CoV deposited droplets are projected during biomicroscopy and to discuss what kind of precautions should be taken in ophthalmic practice. Methods A coupled fluid-structure system comprising smoothed particle hydrodynamics and the finite element method has been built to assess the projection of droplets spreading from an infected person. Different conditions based on the maximum exit flow velocity from the infector's mouth during the ophthalmic examination were modeled. Results During exhalation, for which the exit flow is similar to 1000 mm/s, the average horizontal distance of the flow front was similar to 200 mm while individual particles can reach up to similar to 500 mm. In case of coughing or sneezing (corresponding to an exit flow of similar to 12,000 mm/s), the average horizontal distance of the flow front was similar to 1300 mm. Conclusion During the ophthalmic examination, the proximity to the patient's nose and mouth was observed to be less than the horizontal distance of flow front particles. Even though mounted breath shields are used, particles flew beyond the shield and contaminate the ophthalmologist. Compared with the current protective breath shields, the use of a larger shield with a minimum radius of 18 cm is needed to decrease viral transmission.
Citation Count: 1
Algısal çelişki ve tepki rekabeti: Stroop etkisine ilişkin olay-ilişkili potansiyeller
(2009) Bekçi, Belma; Karakaş, Sirel
Amaç: Mevcut çalışmanın amacı, algısal çelişki ve tepki rekabeti hipotezleri ile açıklanmaya çalışılan Stroop etkisinin yol açtığı elektrofizyolojik aktiviteleri analiz etmektir.Yöntem: Örneklem üniversite popülasyonundan 50 (23 kadın 27 erkek) sağlıklı gönüllü yetişkini içermiştir. Uyarım, kayıt ve analiz işlemlerinde NeuroScan 4.2 donanım-yazılım sistemi kullanılmıştır.Bulgular: Stroop bozucu etkisi, davranışsal olarak, uyuşmayan uyarıcılara ilişkin tepki zamanının uzaması ve tepki verilmekte gecikilen uyarıcı sayısının artması olarak elde edilmiştir. Temel bileşenler analizinde (TBA) Stroop performansının seçici dikkat, bozucu etki ve bozucu etkiye direnç faktörlerini içerdiği belirlenmiştir. Stroop bozucu etkisi, elektrofizyolojik olarak ise uyuşmayan uyarıcılara ilişkin P3 ve N4, yanlış tepkilere ilişkin olarak da N2, P3, N3 ve N4 bileşenlerinin genliklerinde artış olarak elde edilmiştir.Sonuç: P3 ve N4 zirvelerine ilişkin genlik artışının çelişki belirleme sürecini yansıttığı sonucuna varılmıştır. Yanlış tepkilere ilişkin genlik artışı değişiklikleri ise karmaşıktır. N2 ve P3 bileşenlerindeki genlik artışı yalnızca uyuşmayan uyarıcılarda, N3 ve N4 bileşenlerinin genliği ise hem uyuşmayan hem de uyuşan uyarıcılarda artmıştır. Söz konusu daha erken ve geç aktivitelerin sırasıyla tepki rekabeti ve hata belirleme süreçleri ile ilişkili olduğu sonucuna varılmıştır. Söz konusu bulgular, Stroop etkisini açıklamada öne sürülen algısal çelişki ve tepki rekabeti hipotezlerinin her ikisinin de geçerli olduğunu desteklemektedir.
Citation Count: 4
Alpha Head on Collision with a Fixed Gold Nucleus, Taking into Account the Relativistic Rest Mass Variation as Implied by Mass-Energy Equivalence
(Polish Acad Sciences inst Physics, 2014) Yarman, T.; Arik, M.; Kholmetskii, A.; Altintas, A. A.; Ozaydin, F.; Enerji Sistemleri Mühendisliği / Energy Systems Engineering
We reformulate the Rutherford scattering of alpha particle for a head on collision, taking into account the rest mass variation of the particle, as implied by the energy conservation law. Our relativistic reformulation (which includes the energy conservation) constitutes a new example for the breakdown of the Lorentz invariance. Briefly speaking, even at rest or during the whole scattering process, the distance between the alpha particle and the gold nucleus is not invariant but depends on the frame of the observer attached to either object. According to our relativistic reformulation, we also provide a new set of Lorentz transformations.
Citation Count: 1
Altaic tradition: Turkey
(John Benjamins Publishing Company, 2019) Demircioǧlu,C.; Mütercim Tercümanlık (İngilizce) / Translation and Interpreting (English)
This report offers a brief historical and cultural lexicon of the Turkish terms/ concepts for translation by means of available primary and archival materials and proposes a small-scale genealogy of Altaic tradition in two main parts. In the first part, a special focus is on Uighur Turkish in Central Asia (Old Turkic period, 9th century), followed by Anatolian Turkish developed in Asia Minor since the 11th century (West Turkic). Due to insufficient historical research and data on translation within the paradigm of Translation Studies, the report will not scan translational terms/concepts in Qarakhanid, Qharezm and Chagatai Turkish, which are members of East Turkic tradition. In the second part, the report reviews translation as concept and practice, focusing especially on the Turkish literary discourse of the late 19th century since this era is a period of the Turks' encounter with Europe, hence, a period of shifting civilization from the East to the West, which led to a change in translation conception (see Paker 2006; Demircioǧlu 2005). © 2019 John Benjamins Publishing Company.
Citation Count: 0
Analysis of complications following posterior vertebral column resection for the treatment of severe angular kyphosis greater than 100
(2017) Balioğlu, Mehmet Bülent; Albayrak, Akif; Atıcı, Yunus; Kargın, Deniz; Mert, Muhammed; Kaygusuz, Mehmet Akif
Objective: The aim of this study was to evaluate the complications, efŞcacy and safety of posteriorvertebral column resection (PVCR) in severe angular kyphosis (SAK) greater than 100.Methods: The medical records of 17 patients (mean age 17.9 (range, 9e27) years) with SAK who underwent PVCR, were reviewed. Mean follow-up period was 32.2 (range, 24e64) months. Diagnosis of thepatients included congenital kyphosis in 11 patients, post-tuberculosis kyphosis in 3 patients andneuroŞbromatosis in 3 patients. The sagittal plane parameters (local kyphosis angle, lumbar lordosis,sagittal vertical axis, pelvic tilt, sacral slope and pelvic incidence) were measured in the preoperative andthe early postoperative periods and during the last follow-up on the lateral radiographs.Results: The mean preoperative localized kyphosis angle was 121.8(range, 101e149). The mean localkyphosis angle (LKA) was 71.5at postoperatively evaluation (p< 0.05). Complications were detected in12 patients (70.6%) with spinal shock in 4 patients, hemothorax in 3 patients, postoperative infection in 2patients, dural laceration in 2 patients, neurological deŞcit in 2 patients (1 paraplegia and 1 root injury),the shifted cage in 2 patients and rod fracture in 2 patients. Neurological events occurred in six patients(35%) with temporary neurological deŞcit in 5 patients and permanent neurological deŞcit in 1 patient.Conclusion: PVCR is an efŞcient and a successful technique for the correction of SAK. However, it can leadto a large number of major complications in SAK greater than 100.Level of evidence: Level IV, therapeutic study.
Citation Count: 14
Analysis of complications following posterior vertebral column resection for the treatment of severe angular kyphosis greater than 100°
(Turkish Assoc Orthopaedics Traumatology, 2017) Atici, Yunus; Balioglu, Mehmet Bulent; Kargin, Deniz; Mert, Muhammed; Albayrak, Akif; Kaygusuz, Mehmet Akif
Objective: The aim of this study was to evaluate the complications, efficacy and safety of posterior vertebral column resection (PVCR) in severe angular kyphosis (SAK) greater than 100 degrees. Methods: The medical records of 17 patients (mean age 17.9 (range, 9-27) years) with SAK who underwent PVCR, were reviewed. Mean follow-up period was 32.2 (range, 24-64) months. Diagnosis of the patients included congenital kyphosis in 11 patients, post-tuberculosis kyphosis in 3 patients and neurofibromatosis in 3 patients. The sagittal plane parameters (local kyphosis angle, lumbar lordosis, sagittal vertical axis, pelvic tilt, sacral slope and pelvic incidence) were measured in the preoperative and the early postoperative periods and during the last follow-up on the lateral radiographs. Results: The mean preoperative localized kyphosis angle was 121.8 degrees (range, 101 degrees-149 degrees). The mean local kyphosis angle (LKA) was 71.5 degrees at postoperatively evaluation (p < 0.05). Complications were detected in 12 patients (70.6%) with spinal shock in 4 patients, hemothorax in 3 patients, postoperative infection in 2 patients, dural laceration in 2 patients, neurological deficit in 2 patients (1 paraplegia and 1 root injury), the shifted cage in 2 patients and rod fracture in 2 patients. Neurological events occurred in six patients (35%) with temporary neurological deficit in 5 patients and permanent neurological deficit in 1 patient. Conclusion: PVCR is an efficient and a successful technique for the correction of SAK. However, it can lead to a large number of major complications in SAK greater than 100 degrees. Level of evidence: Level IV, therapeutic study. (C) 2017 Turkish Association of Orthopaedics and Traumatology. Publishing services by Elsevier B.V.
Citation Count: 7
An analysis of general surgery theses set up between years 1998-2018 in Turkey: Evidence levels and publication rates of 1996 theses;
(Bilimsel Tip Yayinevi, 2020) Ferhatoğlu,M.F.; Kıvılcım,T.; Kartal,A.; Filiz,A.İ.; Kebudi,A.
Objective: Setting up and advocating a thesis is mandatory at the end of the residency training program to become a specialist in general surgery according to the regulations on medical specialization in Turkey. Writing a thesis helps the resident to learn to ask structured questions, assembling the most accurate study design, managing the study process, collecting the results and building a conclusion with medical implications. In this descriptive study, we aimed to investigate the publication rates of the theses written in the field of general surgery and to assess the properties of the published theses. Material and Methods: We performed an online search on September 1, 2018, about the theses of general surgery residents on the website of National Thesis data center of Academic Educational Board in Turkey including theses of medical residents in university-affiliated hospitals and analyzed theses accomplished between 1998-2018. The publication status of the theses was assessed by the entry of author name, the title of the theses and keywords of the theses by using the search engines of PubMed, Google Scholar and Turkish Academic Network and Information Center Turkish Database (ULAKBIM). Data were presented in a descriptive form as absolute numbers and percentages. Results: Between 1998-2018, 1996 theses were completed. 393 (20.5%) of these were published in a journal, and 288 (14.4%) were published in a journal indexed in SCI/SCIE. According to research methodologies, 79.2% of the experimental studies were published in SCI/SCIE indexed journals. Conclusion: Publication rates of the theses in the field of general surgery are low as they are in other specialties of medicine. This descriptive study might give an idea about the low scientific publication rates of general surgery theses. Further studies are needed to understand the underlying factors, which are responsible for this scant scientific performance. © Copyright 2020 by Turkish Surgical Society.
Citation Count: 0
Analysis of settlement parameters of architecture faculties on university campus
(Enpress Publ Llc, 2024) Doraj, Parisa; Ozyilmaz, Havva; Akar, Umit
The selection of a suitable place for an activity is an important decision made for a project, which requires assessing it from different points of view. Educational use is one of the most complicated and substantial uses in urban space that requires precise and logical attention to its location and neighborhood with similar and consistent uses. Faculties of universities are educational spaces that should be protected against physical and moral damage to create a healthy educational environment. To do this, it is necessary to find and assess the factors affecting the location of educational spaces. The extant study aimed at finding and assessing the factors affecting the location of educational spaces to locate art and architecture schools or faculties in 4 important universities. The present study is applied developmental research in terms of nature and descriptive-analytical in terms of method. This study used the AHP (Analytical Hierarchy Process) weighing and controlled the prioritization through the TOPSIS (Technique for Order Preference by Similarity) technique in the methodology phase. Since there was no criterion and metric for these centers, six were chosen as the primary metrics after reviewing the relevant theoretical foundations, early investigations, and collecting effective data. Finally, the results indicated the most important factors of vehicular or roadway access, pedestrian access, slope, parking, adjacency, neighborhood, and area. Among the mentioned factors, pedestrian access (w: 0.4231) had the highest weight and was the priority in the location of architecture faculty in studied campuses and areas inside the universities.
Citation Count: 0
Anisotropic Differential Operators with Parameters and Applications
(Springer, 2014) Shakhmurov, V. B.
In the paper, we study the boundary-value problems for parameter-dependent anisotropic differential-operator equations with variable coefficients. Several conditions for the uniform separability and Fredholmness in Banach-valued L (p) -spaces are given. Sharp uniform estimates for the resolvent are established. It follows from these estimates that the indicated operator is uniformly positive. Moreover, it is also the generator of an analytic semigroup. As an application, the maximal regularity properties of the parameter-dependent abstract parabolic problem and infinite systems of parabolic equations are established in mixed L (p) -spaces.
Citation Count: 0
ANTHROPOMETRIC PROFILES OF YOUNG RHYTMIC GYMNASTIC ATHLESTES ACCORDING TO THEIR PARENTAL NUTRITIONAL BEHAVIOR
(Univ Ljubljana, 2022) Uslu, Burcu; Okudan, Begum; Bozdemir, Ezgi; Alphan, Mueveddet Emel
Rhythmic gymnastics is a sport that is supported by strength, speed and endurance with an emphasis on flexibility and coordination. It is assumed that low fat percentage, normal height, low body weight, and elegant and thin structure influence the performance of the athletes because it provides an aesthetically advantage in this sports branch. The aim of the study was to reveal the anthropometric properties in rhythmic gymnastics athletes, and to examine the changes and relationships of these parameters according to their parents' diet. A questionnaire with socio-demographic information, Parental Feeding Style Questionnaire, was used to gather data. The data on children's BMI, waist circumference and upper middle arm circumference were also included; these measurements were all taken by the same researcher. It was determined that the scores obtained from the parent feeding style scale differed according to the waist circumference of the child (p <0.05). It can be concluded that the scores obtained from the parent feeding style scale and its sub-dimensions of promoting to eat /encouraging feeding and instrumental feeding differ according to the child's upper middle arm circumference (p <0.05). As a result of the research, some sociodemographic and anthropometric features seem to affect the parents' feeding style of their children. The results obtained from this study can be used as a guide when creating forward-looking nutrition models for children engaged in rhythmic gymnastics, and planning the nutritional education for their parents.
Citation Count: 1
Antibacterial efficacy of 810-nm diode laser on the biofilm formation by Enterococcus faecalis in root canals: an in vitro study
(Springer International Publishing, 2020) Benezra,M.K.; Karaaslan,E.; Doymaz,M.Z.; Dincer,A.N.
Aim: This study aimed to evaluate the antibacterial efficacy of 810-nm diode laser on the root canals infected with Enterococcus faecalis biofilm-like structure by using comparable and safe parameters. Methodology: The root canals of 52 extracted human single-rooted teeth were prepared, 4 teeth allocated as negative control and 48 teeth inoculated with E. faecalis for 3 weeks. The teeth were then randomly divided into the following 4 experimental groups: Group NaOCl (n = 12), 17% EDTA + 5.25% NaOCl + saline; Group DL1 (n = 12), 17% EDTA + 1 W diode laser + saline; Group DL2 (n = 12), 17% EDTA + 1.5 W diode laser + saline; Group S (n = 12), Saline. Samples were obtained from dentin chips before and after the interventions. A reduction in colony count was assessed by counting the colony-forming units. Results: Compared to the control group, significant reductions were noted in E. faecalis colony counts in all groups (p <.05) except Group S (p >.05). The greatest reduction in colony count (98.9%) was noted in the Group NaOCl. The difference in this respect between the Group DL2 and Group S (p <.05) was significant; however, no significant difference was noted between Group DL1 and Group S (p >.05). Conclusion: Our results demonstrated two different parameters of 810-nm diode laser showing the significant antibacterial effect on E. faecalis biofilm but it was not as effective as NaOCl irrigation. © 2020, Springer Nature Switzerland AG.
Citation Count: 2
Apparent paradoxes in classical electrodynamics: a fluid medium in an electromagnetic field
(Iop Publishing Ltd, 2008) Kholmetskii, A. L.; Yarman, T.; Enerji Sistemleri Mühendisliği / Energy Systems Engineering
In this paper we analyse a number of teaching paradoxes of classical electrodynamics, dealing with the relativistic transformation of energy and momentum for a fluid medium in an external electromagnetic field. In particular, we consider a moving parallel plate charged capacitor, where the electric attraction of its plates is balanced by the pressure of gas convicted between the plates.

Browse

Browsing Okan Üniversitesi / Okan University by Scopus Q "Q3"