232 research outputs found
Near Source Effects and Engineering Implications of Recent Earthquakes in Turkey
The variation of both structural and geotechnical consequences of near-source effects are shown for densely populated environments, Kocaeli and Düzce (Turkey), situated on an alluvial fan at the western part of the 1500 km long North Anatolian fault (NAF) that resembles the San Andreas fault in California with its right-lateral and strike slip faulting mechanism as well as remarkably similar length and capability of generating damaging earthquakes. Recordings from two recent destructive earthquakes occurred in 1999 on the NAF suggest that nearsource impulse type ground motions may generate large input energy demands that have to be dissipated with few large displacement excursions. The discussion is therefore focused on the seismic wave propagation mechanism related to the unexpected damages at the nearfield sites. The observation results proved the high intensity velocity at the damage suffering areas due to the soil layer resonance and, furthermore, due to the bump effect by wave interferences traveling vertically and horizontally. While there are potentially other factors contributing to damage (such as topographic and basin effects, liquefaction, ground failure, or structural deficiencies), the amplification of ground motion due to local site conditions plays an important role in exacerbating the seismic damages in disaster belt area. The field observations regarding this phenomenon supplemented with the near-field strong motion interpretations are presented, and significance of local soil effects in the near-field region is assessed in the course of this study
Clonal relation of nasal MRSA carrier status among hospital personnel, hospitalized patients and community
Objectives: Nasal colonization of methicillin-resistant Staphylococcus aureus (MRSA) among the healthcare workers(HCWs), hospitalized patients, and healthy individuals was investigated by pulsed field gel electrophoresis (PFGE) for definingof clonally distribution of them.Methods: Totally 403 healthcare personnel, 744 patients, and 204 healthy individuals from the population were enrolled.Microbiological procedures were performed in the Bacteriological Laboratory at the Clinical Microbiology and InfectiousDiseases Department of Firat University, and PFGE procedures were performed in the Microbiology Department of InonuUniversity.Results: Staphylococcus aureus was isolated in 296 (21.9%) of 1351 nasal swabs, and 69 out of 296 (23.3%) were defined asMRSA. Nasal S. aureus carrier state was identical between the patients and HCWs carrier state (p=0.14). It was significantlylower in healthy subjects than the other groups (p=0.02). Seventeen (25.8%) of 66 MRSA strains were defined to be in thecluster. These strains were in 7 different clusters. Among the typed strains, 21 had close relationship, 2 had possible relationship,and 26 had no relation. PFGE pattern was defined in 33 (50%) out of 66 strains and it was inconclusive in 3 strains.Conclusions: MRSA strains can be transferred commonly in the same hospital, among the hospitals located in the sameregion and the population. The results might be the indicators of increasing frequencies in population based MRSA infections.Multi-center studies are required to define clonally distribution of MRSA and the explanation of epidemiology maybe helpful for preventing and controlling of MRSA related infections. J Microbiol Infect Dis 2013; 3(2): 49-55Key words: MRSA, nasal carrier, PFGE
The relationship of graft survival and herpes simplex virus latency in recipient corneal buttons
Orhan Aydemir1, Peykan Türkçüoglu1, Yasemin Bulut2, Ahmet Kalkan31Firat University School of Medicine, Department of Ophthalmology, Elazig, Turkey; 2Firat University School of Medicine, Department of Microbiology, Elazig, Turkey; 3Firat University School of Medicine, Department of Infectious Diseases, Elazig, TurkeyPurpose: To demonstrate relationship between herpes simplex virus (HSV) corneal latency and graft survival.Methods: Prospective case control study. 28 recipient corneal buttons and donor cornea-scleral remnants were examined for HSV DNA with polymerase chain reaction (PCR). None of the recipient had a history of HSV infection. Serum samples of graft recipients were analyzed for the presence of anti-HSV IgG and IgM with enzyme-linked immunosorbent assay technique. All corneas were free of stromal scarring or epithelial defect before sampling and had an endothelial cell density of >2000 cells/mm2.Results: In twenty three patients (82%) anti-HSV IgG was detected in serum. In none of the recipients anti-HSV IgM was positive. HSV DNA was positive in six out of twenty eight (21%) of the recipient corneal buttons and none of the donor cornea-scleral remnants. In eighteen months follow-up period three out of six (50%) HSV DNA positive and one out of twenty-two (4.5%) HSV DNA negative patients experienced late endothelial failure that was statistically significantly different (p = 0.022). Conclusion: Even without a history of HSV keratitis, presence of latent HSV virus in recipient cornea is an important risk factor for subsequent graft survival.Keywords: herpes simplex virus, polymerase chain reaction, corneal latency, corneal graft surviva
Türkiye’de Bulunan Geçici Koruma Statüsündeki Suriyelilerin Türkiye’deki Din Eğitimi Deneyimlerinin Değerlendirilmesi
Evrensel bir gerçeklik olan göç, insanlığın varoluşundan bu yana ülkelerin geleceklerini etkileyen sosyal bir vakıa olmuştur. Türkiye bu tarihi gerçeklik ile zaman zaman yüzleşse de 2011 yılı itibariyle 21.yy’nin en ciddi göç hareketliliğine kapılarını açmıştır. Dolayısıyla, bu kitlesel göç hareketinin Türkiye’ye birçok etkisinden söz etmek kaçınılmaz olmuş ve göçün etkilerini incelemek büyük önem arz etmiştir. Bu çalışmada ülkemize zorunlu göç yapmış olan geçici koruma statüsündeki Suriyelilerin aldıkları din eğitiminin onların gözünden irdelenmesi hedeflenmiş, Türkiye’ de verilen din eğitimini örgün ve yaygın boyutlarıyla ne şekilde deneyimlediklerinin ve din ile ilgili deneyimledikleri bu eğitimin onların anlam dünyasında nelere karşılık geldiğinin ortaya koyulması amaçlanmıştır. Makalemizde yöntem olarak, savaş ve göçü yaşamış bireylerin tecrübelerini derinlemesine anlamak adına ve bu tecrübelerin derinlerinde oluşturduğu ihtiyacı belirlemek için fenomenolojik yöntem kullanılmıştır. Araştırmamız, Ankara’nın Altındağ İlçesi – Ulubey ve Önder mahallelerinde Suriyeli mültecilerin yoğun bir şekilde yaşadığı “Küçük Halep” olarak da adlandırılan bölgede gerçekleşmiştir. Çalışmamızda amaçlı örneklem türlerinden maksimum çeşitlilik örneklem ile çalışma grubu oluşturulmuştur. Yetişkin, çocuk ve eğitimcilerden oluşan 24 Suriyeli ile derinlemesine mülakatlar yapılarak veriler toplanmıştır. Veriler üzerinde yapılan çözümlemelerden; 1. Savaş, Göç ve Din, 2. Türkiye’ de Suriyeli Olmak, 3. Örgün Eğitim Deneyimleri, 4. Türkiye’de Din Eğitimi Deneyimleri olmak üzere dört ana boyuta ulaşılmış, 19 alt tema- kodlama oluşturulmuştur. Sonuç olarak, hem mülteciler hem de ülke vatandaşları açısından pek çok zorluğu beraberinde getiren göç olgusu karşısında, Suriyeli mültecilerin aldıkları din eğitiminin Türkiye’ye uyumlarında önemli etkisinin olduğu tespit edilmiştir. Yaygın din eğitiminde karşılaştıkları bazı din görevlilerinin hayatlarında olumlu yönde dönüm noktası oluşturduğu, buna karşın öz veriye dayanmayan ve önyargı barındıran yaklaşımların ise Suriyeli bireylerin topluma uyumlarını zorlaştırdığı, karşılıklı olarak uyumu reddetme eğilimini arttırdığı görülmüştür. Suriyeli yetişkin, genç ve çocukları anlamanın ve verdikleri kayıplarının farkında olmanın örgün ve yaygın eğitim için son derece belirleyici olduğu sonucuna ulaşılmıştır
Behavior of Reinforced Wall System During the 1999 Kocaeli (Izmit), Turkey, Earthquake
A four-span bridge together with a 10 m-high and 100 m-long bridge approach fill was one of the highway facilities damaged due to surface faulting along the Trans-European Motorway during 1999 Kocaeli Earthquake (Mw 7.4). The fault rupture crossed beneath an overpass bridge within a few meters away from the bridge abutment while damaging the approach fill which was reinforced with a double-faced mechanically stabilized earth wall (MSEW) system. The faulting-induced excessive tectonic ground deformations including near-field seismic shakings were the main sources of damage in the walls. Such effects, along with the others, caused cracks and panel separations in wall faces as a result of a liquefaction-induced differential settlement in the cross section. The performance of the reinforced walls was satisfactory that there was no significant structural damage despite the total collapse of the bridge decks. The wall system provided a unique case history under extreme loading conditions, while proving that they are flexible and can withstand large ground deformations. This paper discusses how the walls performed based on post-earthquake reconnaissance studies. The faulting activity, geology of the site, strong ground motions and damage states in the reinforced wall are discussed in details
Influence of earthquake angle on seismic performance of concrete highway bridges
Cilj je ovog istraživanja procijeniti učinak kuta djelovanja potresa na seizmičko ponašanje betonskog mosta na autocesti. Analiziran je dvostruki prednapeti betonski sandučasti gredni most na autocesti (odvojena konstrukcija za svaki smjer vožnje) kao numerički primjer i to primjenom metode konačnih elemenata. Most je bio izložen djelovanju potresa ubrzanja tla u Erzincanu iz 1992. i to u 19 smjerova čije vrijednosti variraju od 0 ° do 90 ° s povećanjima od 5 stupnjeva. Kako bi se ispitali učinci različitih kutova djelovanja potresa na seizmičku izvedbu, proučene su promjene vrijednosti maksimalnih pomaka, unutarnjih sila te glavnih naprezanja na kolničku konstrukciju mosta, stupova, izolatora i temelja. Rezultati su se znatno promijenili u slučaju različitih kutova djelovanja potresa. Pojavile su se promjene vrijednosti pomaka, unutarnjih sila i glavnih naprezanja pri različitim upadnim kutovima. Drugim riječima, ne postoji jedinstveni upadni kut za svaku konstrukciju.This study aims to evaluate the effect of earthquake angle on the seismic performance of a concrete highway bridge. As a numerical example, a twin prestressed concrete box-girder highway bridge was analysed using finite element methods. The bridge was subjected to the 1992 Erzincan earthquake ground accelerations in 19 directions with values ranging from 0° to 90° in 5-degree increments. To evaluate the effects of different earthquake angles on seismic performance, variations in the maximum displacements, internal forces and principal stresses on the bridge deck, columns, isolator and foundation were studied . The results changed considerably for different earthquake angles. Variations in the displacement, internal forces and principal stresses occurred at different incidence angles. In other words, there is no unique angle of incidence for each structure
Neurotoxicity evaluation of three root canal sealers on cultured rat trigeminal ganglion neurons
The aim of this study was to investigate the possible neurotoxic effects of 3 root canal sealers (RCSs) (AH Plus, GuttaFlow, iRoot SP) on cultured rat trigeminal ganglion (TG) neurons.
Primary cultures of TG neurons were obtained from 1 to 2-day old rats. Freshly mixed RCSs were incubated in sterile phosphate buffered saline and cells were incubated with supernatants of the RCSs for different time intervals (1-, 3-, 6- and 24-h; 1 or 1/10 diluted) and viability/cytotoxicity was tested by counting the number of live cells. Pair of dishes with cells from the same culture incubated with only culture medium was considered as negative controls. Cell images were captured and acquired at x200 magnification using a microscope equipped with a camera using special image program. The viable cells were manually counted assigned from the images for each dose and incubation duration. Data was analysed by using 1-way analysis of variance with Tukey post hoc tests.
There was no significant change in cell viability after short duration of incubation (1- and 3-h) with the supernatant of any of RCSs, except for undiluted-AH Plus at 3-h. When AH Plus was compared with other RCSs, for diluted supernatants, there was only significant difference between iRoot SP and AH Plus at 24-h (P<0.05). Whereas undiluted-AH Plus was significantly more cytotoxic for 3-, 6- and 24-h periods as compared to respective incubation periods of undiluted other groups (P<0.05). GuttaFlow groups had similar neurotoxic effect on cells for all test periods.
All tested RCSs exhibited a variable degree of neurotoxicity on these primary sensory neurons of orofacial tissues, depending on their chemical compositions. GuttaFlow and iRoot SP evoked a less toxic response to TG cells than AH Plus
The diagnostic value of serum copeptin levels in an acute pulmonary embolism
Background: Acute pulmonary embolism (APE) is a common disease which is associated with high mortality and morbidity. Circulating level of copeptin, which was demonstrated to be elevated in heart failure, acute myocardial infarction and pulmonary arterial hypertension, were reported to be independent predictors of poor outcome in recent studies. The aim of the present study was to investigate the clinical utility of copeptin in the diagnosis of APE.
Methods: A total of 90 consecutive patients, admitted to emergency service due to acute chest pain and/or dyspnea and who underwent pulmonary computerized tomography angiography (CTA) due to suspicion of APE, were included in this prospective study. The patients diagnosed with APE were defined as APE (+) group and the remaining individuals with normal pulmonary CTA result were defined as APE (–) group.
Results: Copeptin levels (7.76 ± 4.4 vs. 3.81 ± 1.34 ng/dL; p < 0.001) were higher in the APE (+) group as compared to the APE (–) group. Copeptin was significantly positively correlated with B-type natriuretic peptide (r = 0.434, p < 0.001), D-dimer (r = 0.315, p = 0.003) and troponin I (r = 0.300, p = 0.004) and inversely correlated with arterial oxygen saturations (r = –0.533, p < 0001). When the correlation of copeptin with right ventricular dysfunction parameters was investigated, it was significantly inversely correlated with the tricuspid annular plane systolic excursion (r = –0.521, p < 0.001) and positively correlated with right to left ventricle ratio (r = 0.329, p = 0.024). Copeptin (OR 1.836, 95% CI 1.171–2.878, p = 0.008) was found as a significant independent predictor of APE in a multivariate analysis, after adjusting for other risk parameters.
Conclusions: Copeptin is a promising new biomarker, which may be used to support the need for further investigations and to improve the diagnosis of patients with APE.
Myo-Elektriksel Sinyaller İle İnsansız Kara Aracının Uzaktan Kontrolü
Bu çalışma kapsamında insansız bir kara aracının kişinin el ve parmak hareketleri ile uzaktan kontrolü gerçekleştirilmiştir. Beyinden kol kaslarına iletilen ve kişinin el hareketlerini gerçekleştirmesini sağlayan Elektromiyografi (EMG) sinyalleri, kişinin koluna giydiği sekiz EMG sensör içeren bileklik vasıtası ile gerçek zamanlı olarak alınmıştır. Raspberry pi 3 gömülü sistem kartı üzerinde geliştirilen sinyal işleme, öznitelik çıkarımı ve sınıflandırma algoritmaları kullanılarak anlamlandırılmıştır. Başka bir deyişle el hareketin örüntüsü (el kapama, parmak açma, serçe parmak temas, bilek dışa bükme, vs.) ile EMG sinyal grubu arasındaki ilişkiler tanımlanmıştır. Anlamlandırılan her bir el hareketi araç için bir hareketi kontrol komutu (el kapama: araç ileri, parmak açma: araç dur, serçe parmağa temas: sola dönüş, bilek dışa bükme: sağa dönüş, vs.) olarak kullanılmıştır. Böylece insan – mobil araç etkileşim ağı kurulmuştur. Kurulan insan- mobil araç etkileşim ağı sayesinde el hareketleri ile mobil aracın gerçek zamanlı hareket kontrolü ortalama % 92 başarı ile gerçekleştirilmiştir
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