Microstructural evolution of calcium doped alpha-Al2O3

Effects of different calcium doping levels on the microstructure of high purity [alpha]-alumina was studied as a function of sintering time and temperature using scanning electron microscope (SEM). Samples were prepared from high purity AKP-500, Sumitomo á-alumina powder that contained maximum 13 ppm total cation impurity initially. Extra pure calcium nitrate tetrahydrate (GR for analysis) were used as the calcium source. Alumina powders with calcium concentrations varying from 0 to 1000 ppm (molar ratio of Ca/Al2O3) were dispersed in 2-propanol (analytical reagent) and ball milled for 12 hours with 99.7% pure alumina balls. After drying, powders were pressed first unidirectionally into discs under 28 MPa and then cold isostatically pressed at 250 MPa. Bulk chemical analysis of doped powders were done by ICP-OES. According to ICP results the doped powders contained less than 5 ppm silicon impurity. Sintering of samples were carried out at 1400, 1500 and 16000C for 1 and 12 hours. Microstructural evolution under these conditions were related to calcium excess at the grain boundaries (ÃCa). ÃCa was calculated using a simplified McLean-Langmuir adsorption model. As expected with increasing sintering time and temperature the average grain size increased. Under all sintering conditions, the grains were uniform in size and equiaxed for low calcium concentrations. The grain morphology became elongated when the calcium concentration at the grain boundaries reached calcium excess of ÃCa=3-3.5 calcium atoms/nm2 in all samples. For the samples that were sintered at 15000C and 16000C, slab like abnormally grown grains appeared between a critical calcium excess concentration of ÃCa=4.5-8 calcium atoms/nm2. With abnormally grown grains a dramatic increase in average grain size was observed. However, when the calcium concentration was increased further, above certain calcium excess concentration depending on sintering temperature a significant decrease in grain size was observed. In contrast to samples sintered at 15000C and 16000C, when the samples sintered at 14000C, although the calcium coverage exceeded ÃCa=11 calcium atoms/nm2, only few grains grew abnormally without affecting the average grain size. Observations clearly indicated that calcium atoms cause elongated (slab like) grain morphology when their excess concentrations reach a critical level at the grain boundaries. This is most likely due to the preferential segregation of calcium ions to basal plane in á-alumina as previously shown in literature on alumina with calcium and silicon impurities. In this study, it is indisputably shown that calcium is responsible for the elongated grain morphology observed in polycrystalline alumina. Results obtained in this investigation supported the argument that calcium has an influence on abnormal grain growth (AGG) in [alpha]-Al2O3. However, it appears that at least one other impurity may be necessary, most likely silicon, to trigger AGG

Marka ve Marka Kişiliği Algısı: Bir Üniversite Örneği Brand And Brand Perception: An Example of University

Diğer birçok alanda olduğu gibi eğitim alanındaki rekabette gittikçe yoğunlaşmaktadır. Bu nedenle, rekabet avantajı elde etmek isteyen kurumlar markalaşmaya önem vermektedir. Bu çalışmanın amacı, 2008 yılında kurulan Ardahan Üniversitesi'nin (ARÜ) marka kişiliğinin iç ve dış paydaşlar açısından nasıl algılandığını belirlemek ve paydaşlar arasındaki algı farkını belirlemektir. Araştırma kapsamında, Aaker (1997) tarafından geliştirilen marka kişiliği ölçeği kullanılmış ve toplam 612 katılımcıdan veri toplanmıştır. Analizler sonucunda marka kişiliği ölçeği dört ana faktör altında toplanmıştır. Bunlar “Samimiyet-Yetkinlik, Coşku-Gelişmişlik, Sertlik ve Genç-Sade-Dışa Dönük olarak gruplanmıştır. İlk iki faktörde katılımcılar yargılara ilişkin kararsız iken son iki faktörde bu iki kişilik özelliği ile ilgili yargılara katılmamaktadır. Paydaşlar açısından bu faktörlere katılımları arasında farklılık olup olmadığına göre yapılan analizlerde ise Coşku-Gelişmişlik ve Sertlik boyutunda öğrencilerin diğer gruplara kıyasla daha olumluya yakın algıladığı görülmüştür. Samimiyet ve Yetkinlik ile Genç-Sade-Dışa Dönük boyutunda paydaşlar arasında bir farklılık bulunmamıştır. Competition in the field of education is becoming more and more intense, as is be the case with many other fields. For this reason, institutions that want to gain competitive advantage attach importance to branding. The purpose of this study is to determine how the brand personality of Ardahan University (ARÜ), which was established in 2008, how is perceived in terms of internal and external stakeholders and to determine the difference between the stakeholders. The brand personality scale developed by Aaker (1997) was used and data were collected from a total of 612 participants As a result of the analyzes, brand personality scale was collected under four main factors.These are grouped as "Sincerity-Competence, Enthusiasm-Development, Hardness and Young-Simple-Outward Turning. The participants in the first two factors are undecided about the judgments while they are not participated in the judgments about the last two factors. In Analyzes made on the basis of whether there is a difference between the participation of these factors in terms of stakeholders are showed that the students perceived more positively than the other groups in the dimension of enthusiasm-development and hardness. There is no difference between stakeholders in the dimension of Sincerity and Competence and Young-Simple-Outward Turnaroun

DNA Repair Based Therapy in Oncology and Neurodegeneration

WOS: 000378333000015

The frequency of Duchenne muscular dystrophy/Becker muscular dystrophy and Pompe disease in children with isolated transaminase elevation: results from the observational VICTORIA study

IntroductionElevated transaminases and/or creatine phosphokinase can indicate underlying muscle disease. Therefore, this study aims to determine the frequency of Duchenne muscular dystrophy/Becker muscular dystrophy (DMD/BMD) in male children and Pompe disease (PD) in male and female children with isolated hypertransaminasemia.MethodsThis multi-center, prospective study enrolled patients aged 3–216 months with serum alanine transaminase (ALT) and/or aspartate transaminase (AST) levels >2× the upper limit of normal (ULN) for ≥3 months. Patients with a known history of liver or muscle disease or physical examination findings suggestive of liver disease were excluded. Patients were screened for creatinine phosphokinase (CPK) levels, and molecular genetic tests for DMD/BMD in male patients and enzyme analysis for PD in male and female patients with elevated CPK levels were performed. Genetic analyses confirmed PD. Demographic, clinical, and laboratory characteristics of the patients were analyzed.ResultsOverall, 589 patients [66.8% male, mean age of 63.4 months (standard deviation: 60.5)] were included. In total, 251 patients (188 male and 63 female) had CPK levels above the ULN. Of the patients assessed, 47% (85/182) of male patients were diagnosed with DMD/BMD and 1% (3/228) of male and female patients were diagnosed with PD. The median ALT, AST, and CPK levels were statistically significantly higher, and the questioned neurological symptoms and previously unnoticed examination findings were more common in DMD/BMD patients than those without DMD/BMD or PD (p < 0.001).DiscussionQuestioning neurological symptoms, conducting a complete physical examination, and testing for CPK levels in patients with isolated hypertransaminasemia will prevent costly and time-consuming investigations for liver diseases and will lead to the diagnosis of occult neuromuscular diseases. Trial RegistrationClinicaltrials.gov NCT04120168

Örgütsel vatandaşlık davranışı ile kişilik arasındaki ilişki üzerine bir araştırma

Anahtar Kelimeler: Örgütsel Vatandaşlık Davranışı, Kişilik, Kişilik Alt Boyutları ÖRGÜTSEL VATANDAŞLIK DAVRANIŞI İLE KİŞİLİK ARASINDAKİ İLİŞKİ ÜZERİNE BİR ARAŞTIRMA Günümüzde sürekli değişen çevresel koşullar karşısında rekabet üstünlüğünün elde edilmesi ve sürdürülmesinde örgütlerin performanslarını artırarak örgütsel başarıyı yakalayabilmeleri, fiziksel ve finansal sermayeleri yanında beşeri sermayelerine gerekli önemi vermeleriyle mümkün olmaktadır. Çalışanların bilgi, beceri ve birikimlerinden oluşan beşeri sermaye, örgütlerin rekabet üstünlüğünü yakalamalarında önemli rol oynayarak, örgütsel performansın artırılmasına katkıda bulunan ve örgütleri başarıya götüren temel faktörlerden birisi olarak karşımıza çıkmaktadır. Beşeri sermaye kapsamında entelektüel ve sosyal sermayelerin kullanılmasına ilişkin olarak, çalışanların biçimsel rol davranışları dışında gönüllü olarak yaptıkları ve örgüt performansını artıran biçimsel olmayan rol dışı davranışlar örgütlerin rekabet üstünlüğünü elde etmede giderek ön plana çıkmaktadır. Bu açıdan günümüzde örgütsel performansın artırılması ve rekabet avantajının yakalanmasında giderek artan bir faktör çalışanların örgütsel vatandaşlık davranışlarıdır. Yaptığımız bu çalışmada bu davranışlar ele alınarak irdelenecek ve beş faktör model kişilik özelliğinin (dışa dönüklük, gelişime açıklık, duygusal denge, uyumluluk ve sorumluluk) çalışanların ekstra rol davranışı olarak nitelendirilen örgütsel vatandaşlık davranışı sergileme sıklığının, kişilik özelliklerine göre değişiklik gösterip göstermediği araştırılacaktır. Çalışmanın amacı doğrultusunda tasarlanan araştırma, Şişli Sosyal Güvenlik Merkezinde görev yapan 240 çalışan üzerinde gerçekleştirilmiştir. Çalışmanın ilk iki bölümünde bahsedilen ilişkilerle ilgili teorik altyapının oluşturulmasına çalışılmıştır. İlk bölüm örgütsel vatandaşlık davranışı, ikinci bölüm kişilik kavramı hakkında genel bir perspektif kazandırmayı amaçlamaktadır. Araştırmanın son bölümünde ise iki değişken seti kullanılarak kişilik özellikleri ile örgütsel vatandaşlık davranışı boyutları arasında ilişki aranmıştır. Yine son bölüm içerisinde sosyo-demografik değişkenler bakımından (yaş, cinsiyet, öğrenim durumu, medeni durum, toplam çalışma süresi, işyerindeki çalışma süresi, aylık gelir ve pozisyon) ÖVD’ de bir farklılık olup olmadığı araştırılmıştır. Araştırma sonuçlarına göre; örgütsel vatandaşlık davranışı sergileme sıklığı ile kişilik arasında orta dereceli anlamlı bir ilişki saptanmıştır. Ayrıca, ÖVD ile kişiliğin alt boyutları olan (sorumluluk, dışadönüklük, uyumluluk ve gelişime açıklık) arasında pozitif yönlü anlamlı bir ilişkisinin olduğu gözlemlenirken duygusal denge boyutu ile ÖVD arasında oldukça düşük negatif yönlü anlamlı bir ilişkisinin olduğu ortaya çıkmıştır. Katılımcıların sosyo-demografik özelliklerinden cinsiyet ve aylık gelir değişkeni dışındaki değişkenlerin örgütsel vatandaşlık davranışı sergileme sıklığı üzerinde etkili olduğu tespit edilmiştir. Keywords:Organizational Behavior, Organizational Citizenship Behavior, Personality, Personality Attributes ABSTRACT A STUDY ON THE RELATIONSHIPS BETWEEN ORGANIZATIONAL CITIZENSHIP BEHAVIOR AND PERSONALITY Achieving and maintaining competitive advantage is getting harder in rapidly changing environmental conditions. Thus, in addition to the physical and financial capital, human capital is considired to be an important factor that influences organizational performance. Human capital is a collection of individual knowledge, talents, skills and experience and has a key role in achieving competitive advantage for organizations. Human capital that includes social and intellectual capital are related to increase informal behavior within organizations such as individuals’ voluntarily acts in workplace. Organizational citizenship behavior (OCB), is an important aspect of human behavior at work, and defined as a concept that contributes to organizational performance and creates competitive advantage for organizations. In this study, the relationships between organizational citizenship behavior and the big five personality traits (openness to experience, conscientiousness, extraversion, agreeableness, and emotional stability) were examined whether the participants’ level of OCB differs according to their personality trait. The study group composed of 240 social security workers working in the department of Şişli, İstanbul. Aim is to give a general perspective in organizational citizenship behavior in the first chapter and in the concept of personality in the second chapter. İn the final chapter of the research, the relationship between personality traits dimensions and organizational citizenship behavior has been searched for by using two sets of variables. Again in the final chapter, the effect of gender, age, education, marital status, total working time, seniority year, income and position on organizational citizenship behavior has been investigated. The results showed significant but how relationships between OCB and personality traits. We found a positive and meaningful correlation between OCB and personality traits dimensions (openness to experience, conscientiousness, extraversion, agreeableness). We also found out that a significant negative correlation between OCB and emotional stability. Furthermore, significant associations were determined between socio-demografic (gender, age, education, marital status, total working time, seniority year, income and position) variables and OCB

Serum Procalcitonin as a Biomarker for the Prediction of Bacterial Exacerbation and Mortality in Severe Copd Exacerbations Requiring Mechanical Ventilation

Background: Procalcitonin (PCT) is being used as a marker of bacterial infections. Although there are several studies showing the diagnostic yield of PCT to differentiate bacterial involvement in chronic obstructive pulmonary disease exacerbations (COPDE), the prognostic yield of PCT in severe COPDE has been studied less. Objectives: The primary aim was to determine whether the level of serum PCT at admission in severe COPDE serves as a prognostic biomarker for hospital mortality. The secondary aim was to determine the role of PCT in identifying a bacterial exacerbation. Methods: A total of 63 COPDE patients (median age 71 years; male 58.7%) were retrospectively analyzed from our intensive care unit database. Results: The hospital mortality rate was 23.8%. Admission PCT levels were higher in patients who died during hospitalization (0.66 vs. 0.17 ng/ml; p = 0.014). This association between hospital mortality and serum PCT level remained significant in a multivariate analysis; for every 1 ng/ml increase in PCT level, hospital mortality increased 1.85 times (odds ratio; 95% confidence interval: 1.07-3.19; p = 0.026). The optimal admission PCT threshold was 0.25 ng/ml in order to discern patients who had bacterial exacerbation with a sensitivity of 63%, a specificity of 67%, and a negative predictive value of 80%. The negative predictive value increased to 89% when both the admission and followup PCT levels remained <0.25 ng/ml. Conclusion: This study shows that admission PCT levels have a prognostic importance in estimating hospital mortality among patients with severe COPDE. A PCT level <0.25 ng/ml at the time of admission and during follow-up is suggestive of the absence of a bacterial cause of COPDE. (C) 2016 S. Karger AG, BaselWoSScopu

Calcium in alpha-alumina: the myth and some EM observations

Changes in the microstructure of alpha alumina with increasing amounts of calcium concentrations in the temperature range between 1400degreesC to 1600degreesC were studied by using various electron microscopy techniques. Variations in the average grain sizes were related to hypothetical excess calcium amount at the grain boundaries (Gamma(Ca)) assuming negligibly small solubility of calcium in bulk alpha-alumina. analytical and high-resolution transmission electron microscopy studies were done on these Ca-doped alumina ceramics. Under all sintering conditions, the grains were uniform in size and equi-axed for low calcium concentrations (<3 Ca-atoms/nm(2)). The grain morphology became elongated when the calcium concentration at the grain boundaries reached calcium excess of Gamma(Ca) = 3-3.5 Ca-atoms/nm(2) in all samples. For the samples that were sintered at 1500degreesC and 1600degreesC, slab like abnormally grown grains appeared for critical calcium excess concentrations of Gamma(Ca) = 4.5-8 Ca-atoms/nm(2). No amorphous triple point pocket and grain boundary phases and/or Films were observed by high resolution electron microscopy. SEM/EDS chemical analysis showed precipitation of calcium hexa-aluminate precipitates that are as large as the matrix alumina grains after certain calcium excess level