31 research outputs found
Bilateral leukocoria in infant with afibrinogenemia
M Necati Demir1, Mehmet Akif Acar1, Yusuf Ziya Aral2, Nurten Ünlü11Ankara Education and Research Hospital, Department of Ophthalmology, Ankara, Turkey; 2Aydin Menderes University, Faculty of Medicine, Department of Pediatric Hematology, Aydin, TurkeyPurpose: To report a bilateral leukocoria case in a patient suffering from afibrinogenemia.Methods: An observational case where congenital afibrinogenemia was presented with bilateral retinal and vitreous hemorrhages that proceeded to vitreoretinal surgery was presented. In addition, complete ophthalmic and radiological examinations and vitreoretinal surgery were performed.Results: Right eye had a complete recovery while the left eye showed serious proliferative vitreoretinopathy and shortened retina. Three years after the surgery clinical examination showed that the right eye was aphacic with an attached retina and clear ocular media while the left eye was phtysic.Conclusion: We recommend broad clotting profile for infants suffering from vitreous or retinal hemorrhages with no obvious physical abuse. Our present case furthermore implies that afibrinogenemia can lie beneath the pathogenesis of bilateral leukocoria and should alert physician for the presence of an afibrinogenemia among several types of bleeding predispositions.Keywords: afibrinogenemia, retinal hemorrhage, vitreous hemorrhage, vitrectom
BİLİŞİM SİSTEMLERİ HİZMETLERİNDE KALİTE YÖNETİMİ VE BİR UYGULAMA
Bir organizasyondaki Bilişim Sistemleri (BS) bölümünün sağladığı hizmetlerin kalitesinin ölçümü; BS Hizmet kalitesi yönetim sürecinin önemli bir aşamasıdır. Bunun sebebi BS bölümünün sağladığı hizmetlerin kalitesinin; sistemi iş süreçlerinde kullanan kişilerin performansları üzerindeki etkisidir. Buna karşılık BS araştırmaları alanında hizmet kalitesi ölçümü konusunda bir ilgi eksikliği mevcuttur. Ölçümle ilgili yapılan çalışmalarda da çoğunlukla A. Parasuman, V. Zeithaml ve L. Berry tarafından geliştirilen ve çoğunlukla pazarlama sektöründe kullanılan SERVQUAL modeli; BS' ye uyumlu hale getirilerek kullanılmaktadır. Fakat SERVQUAL hizmet kalitesi boyutları tüm hizmetlerde ölçüm yapabilecek kadar genel değildir. Özellikle Bilişim Sistemleri Hizmet Kalitesi Ölçümü alanında çalışan bazı araştırmacılar SERVQUAL modelinin yetersiz olduğunu ortaya koymuştur.
SERVQUAL modelinin Bilişim Sistemleri Hizmetleri Kalite ölçümündeki yetersizlikleri ve Bilişim Sistemleri Hizmet Kalitesi araştırmaları alanındaki ilgi eksikliği göz önünde bulundurularak; bu araştırmada bir organizasyonun bilişim sistemleri bölümünün verdiği hizmetin kalitesini ölçmek amacıyla Robert E. Miller'in 2006 yılında yaptığı çalışmasında ortaya koyduğu ISS-QUAL modeli kullanılmıştır. Araştırmamızda, BS hizmetleri son kullanıcıları açısından Hizmet Karşılaşması faktörleri (Hizmet Ortamı, Hizmet Sunumu ve hizmet Ürünü) incelenmiştir. ISS-QUAL ölçüm aracı kullanılarak elde edilen veriler çeşitli demografik ve işle alakalı değişkenler göz önünde bulundurularak değerlendirilmiştir. Araştırma sonucunda; organizasyon çalışanlarının genelde BS bölümünün verdiği hizmetleri kaliteli olarak değerlendirdiği ortaya konulmuştur
An application of data mining and knowledge discovery process in the field of natural gas exploration
Chevron;EMC2;et al.;itkz;MIKRO Information Handling and Distribution FZE;Thomson Reuters8th IEEE International Conference on Application of Information and Communication Technologies, AICT 2014 -- 15 October 2014 through 17 October 2014 -- -- 112596Natural gas exploration has been shifting significantly in the last decades with the progression of new ingenious technologies. However, such technologies generates large amount of data sets and handling of them create problems such as interpretation of data. To solve such problems Data Mining techniques could be used. This work includes the application procedure of Data Mining and Knowledge Discovery to Natural Gas Well Log data using a set of algorithms and a decent Data Mining tool. And the success of each algorithm in terms of the amount of useful rules is compared
Treatment and clinical results in cases with postoperative endophthalmitis
AMAÇ: Postoperatif endoftalmi göz cerrahisinde en çok korkulan
komplikasyonların başında gelmektedir. Bu çalışmada postoperatif
endoftalmi görülme sıklığı, klinik özellikler, risk faktörleri, tedavi
yaklaşımları ve prognoz araştırılmıştır.
GEREÇ VE YÖNTEM: Çalışmaya Ankara Eğitim ve Araştırma
Hastanesi Göz Kliniği'nde postoperatif endoftalmi tanısı alan
olgular dahil edildi. Postoperatif endoftalmi görülme sıklığı,
hastaların oküler ve sistemik hastalıkları, başvuru semptomları, göz
muayene bulguları, bakteriyel kültür sonuçları, uygulanan medikal
ve cerrahi tedaviler ve prognoz incelendi.
BULGULAR: Çalışmaya postoperatif endoftalmi tanısı alan 41 olgu
dahil edildi. Olguların yaş ortalaması 62.8 ± 22.4 yıl idi. Endoftalmi
38 gözde (%92.8) katarakt cerrahisi ve/veya göz içi mercek
implantasyonu sonrasında, 1 gözde (%2.4) trabekülektomi, 1 gözde
(%2.4) penetran keratoplasti ve 1 gözde (%2.4) pars plana vitrektomi
sonrası gelişmişti. Olgularda ameliyat sonrasında hastaneye başvuru
süresi ortalama 15.7 ± 17.5 (2-60) gündü. Vitreus / hümör aköz
kültürü olguların %46.3’ünde pozitifti. Tüm olgulara en az bir kez
intravitreal antibiyotik enjeksiyonu ve 15 (%36.6) olguya pars plana
vitrektomi yapıldı. Işık hissini kaybeden 7 olgudan 3’üne evisserasyon
uygulandı. Olgular ortalama 11.1 ± 4.9 (6-25) ay takip edildi. Takip
sonucunda 7 (%17.1) olguda ışık hissi kaybı görülürken, 12 (%29.3)
olgu ışık hissi-el hareketi, 11 (%26.8) olgu 1 metreden parmak sayma
- <0.1 arasında, 10 (%24.4) olgu 0.1 ve üzerinde görme keskinliği
ile sonuçlandı. Bir (%2.4) olguda yaşından ötürü görme keskinliği
ölçülemedi. Çalışmamızda PPV'nin sonuç görme keskinliği üzerine
etkisi saptanmadı (T test, p = 0.560).
SONUÇ: Postoperatif endoftalmili olgularda acilen intravitreal
antibiyotik yapılması, gerektiğinde tekrarlanması ve gereken
olgularda doğru zamanda uygun cerrahi tedavi ile kabul edilebilir
görsel ve anatomik sonuç elde etmek mümkündür.INTRODUCTION: Postoperative endophthalmitis is one of the
most frustrating complications of ophthalmic surgery. In this study
we aimed to evaluate the postoperative endophthamitis incidence,
clinical features, risk factors, treatment strategies and prognosis in
patients with postoperative endophthalmitis.
MATERIAL AND METHOD: We evaluated postoperative
endophthalmitis cases in Ankara Training and Research Hospital,
Department of Ophthalmology. Postoperative endophthamitis
incidence, ocular and systemic illness, initial symptoms, eye
examination findings, bacteriologic culture results, medical and
surgical treatments and prognosis were investigated.
RESULTS: Forty-one patients with postoperative endophthalmitis
were included in the study. The mean age was 62.8 ± 22.4 years (range
2 months - 90 years). Endophthalmitis developed in 38 eyes (92.8%)
after cataract surgery and/or intraocular lens implantation, in 1 eye
(2.4%) after glaucoma surgery, in 1 eye (2.4%) after penetrating
keratoplasty and in 1 eye (2.4%) after pars plana vitrectomy. The
mean duration of admission to the hospital postoperatively was
15.7 ± 17.5 (2-60) days. Cultures from vitreous / aqueous humor
specimens were positive in %46.3 of the patients. All the cases had at
least one intravitreal antibiotic injection. Pars plana vitrectomy was
performed in 15 cases (36.6%). Evisceration was performed to 3 of
7 patients who lost their sense of light. The mean follow-up was 11.1
± 4.9 (6-25) months. Light perception was lost in 7 cases (17.1%).
Visual acuity was between light perception-hand motion in 12 cases
(29.3%), counting finger from a meter – <0.1 in 11 cases (26.8%), 0.1
and above in 10 cases (%24.4). We couldn’t measure visual acuity in
one (2.4%) preverbal patient. Pars plana vitrectomy didn’t change
functional outcome in our series (T test, p = 0.560).
CONCLUSION: It is possible to obtain acceptable visual and
anatomical results in postoperative endophthalmitis by performing
intravitreal antibiotics immediately, repetition if necessary, and
performing surgical treatment when necessar
Outcomes of Phacoemulsification with Anterior Chamber Maintainer in Vitrectomized Eyes
Pur po se: To evaluate the outcomes of phacoemulsification with anterior chamber maintainer in vitrectomized eyes with complicated
cataract.
Ma te ri al and Met hod: Twenty eyes of 20 patients who developed complicated cataract after pars plana vitrectomy (PPV) were included in
the study. Phacoemulsification with clear corneal incision and foldable intraocular lens implantation was performed. In group 1, anterior
chamber maintainer (ACM) was used during phacoemusification and in group 2, ACM was not used. Pre- and postoperative visual acuities as
well as per- and postoperative complications were reviewed retrospectively.
Re sults: Anterior chamber maintainer was used during the surgery in 12 (60%) cases and was not used in 8 (40%) cases.
Phacoemulsification was performed 16.5±9.2 (4-40) months after PPV. Best-corrected visual acuities were between hand motions and 0.4
preoperatively and between counting fingers from 1 meter and 1.0 postoperatively in group 1. Best-corrected visual acuities were between
hand motions and 0.1 preoperatively and between counting fingers from 1 meter and 0.8 postoperatively in group 2. Posterior capsule was
ruptured in 1 eye peroperatively in group 1. In group 2, phacoemulsification was more difficult due to deep anterior chamber in 8 eyes and
intraoperative complications were iris sphincter rupture in 1 eye and posterior capsule rupture in 1 eye. Mild corneal edema in 7 (58.3%)
eyes, fibrin reaction in 2 (16.6%), intraocular lens decentralization in 1 (8.3%) and posterior capsule opacification in 4 (33.3%) eyes were
the postoperative complications in group 1. Mild corneal edema in 5 (62.5%) eyes, fibrin reaction in 1 (12.5%) and posterior capsule
opacification in 2 (25%) eyes were the postoperative complications in group 2.
Dis cus si on: Complicated cataracts which may develop after PPV can be treated safely with phacoemulsification. Continuous irrigation
during the surgery may provide a stable anterior chamber and prevents surgical complications. (Turk J Ophthalmol 2012; 42: 253-6
Epiretinal membrane related vascular changes in diabetic eyes evaluated with optical coherens tomography angiography
AIM: To evaluate the retinochoroidal microvascular circulation and anatomical structure of diabetic and non-diabetic patients with epiretinal membrane (ERM) with the help of optical coherence tomography angiography (OCT-A) and compare them with healthy control subjects. METHODS: In this prospective, cross-sectional study, a total of 165 eyes were evaluated, including 50 eyes of patients with diabetic ERM, 54 eyes of idiopathic ERM (iERM) patients, and 61 eyes of healthy controls. Macula and disc angiography was performed by OCT-A. Macular vessel density (VD) ratio was evaluated by dividing the VD of the foveal region by the VD of the parafoveal region. Statistical calculations were evaluated at the 95% confidence interval. RESULTS: Macula superficial VD values of ERM cases were lower than that in the control group, while foveal VD was higher in ERM cases. Macula deep VD values of ERM cases were lower in all quadrants, except the fovea. The width of the foveal avascular zone (FAZ) area was significantly lower in the ERM groups, and the FAZ width was lowest in iERM group. Macula superficial VD ratio was significantly higher in the ERM groups, but there was no significant difference between ERM groups. Macula deep VD ratio was significantly higher in the iERM group than in the control group. CONCLUSION: Diabetic and idiopathic ERMs differ in their mechanism of formation and clinical presentation, as well as their effect on retinal vascular structures. If the relationship of increase of retinal thickness with vascular integrity can be demonstrated with OCT-A, then, OCT-A can be used as a guide for ERM prognosis
Passive thermal management of the lithium-ion battery unit for a solar racing car
In this study, a three-dimensional numerical model is developed to investigate the thermal and electrical characteristics of 18 650 lithium-ion battery cells that are used in the solar racing car of Dokuz Eylul University, i.e., SOLARIS. The Newman, Tiedemann, Gu, and Kim (NTGK) battery model of ANSYS Fluent software is implemented to resolve the coupled multiphysics problem. In the analysis, only the discharging period of the battery is considered. Before going through parametric studies under variable weather conditions, time-wise variations of the cell temperature and the battery voltage are evaluated both experimentally and numerically under two different ambient conditions of 0 degrees C and 25 degrees C. Comparative results revealed that reasonable predictions are achieved with the current battery model, and the difference between the predicted battery surface temperature and experimental data is less than 1 degrees C. Following the model validation, the battery performance is numerically examined by applying the battery model to a real race procedure of SOLARIS. Phase change materials (PCMs) with different amounts and melting temperatures are implemented around the batteries, and transient analyses are conducted under real weather conditions. The current study aims to keep the battery temperature of a solar racing car above a certain limit to prevent the overcooling and maintain higher charging capacity. Implementation of PCM with a melting temperature of 26 degrees C yields 3.15% of capacity increment, and such a performance improvement corresponds to 15.51 Wh of extra energy that can be extracted from an individual battery