14 research outputs found

    State of the Art of Gadolinium Zirconate Based Thermal Barrier Coatings: Design, Processing and Characterization

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    The fast consumption of fossil fuel resources and economic competitiveness makes it necessary to increase the efficiency of turbine engines. For this purpose, thermal barrier coating (TBC) has been used on some critical parts of gas turbines. Yttria-stabilized zirconia (YSZ) is widely and commercially used as a ceramic top coat material for TBC in the gas turbine system. On the other hand, the efforts to identify new material having better properties than YSZ have been continued. Gadolinium zirconate (GZ) is a promising alternative TBC material with its lower thermal conductivity, better sintering ability, and higher melting point and phase stability than YSZ. However, recent research studies on the responses of GZ-based TBC materials to the complex demands of modern gas turbine applications should be gathered under a study by comparing them with the results of traditional TBC material. This chapter discusses the GZ based TBC system, specifically addressing issues related to the production process and designing of the coating architecture, in comparison with some of the significant properties with YSZ and the test methodology. Moreover, the chapter also contains information about laser surface modification of the GZ-based TBC

    Biological Subtypes and Survival Outcomes in Breast Cancer Patients with Brain Metastases (Study of the Anatolian Society of Medical Oncology)

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    Background: The aim of this study is to determine the relationship between the survival outcomes and biological subtype in breast cancer patients with brain metastases. Methods: We retrospectively evaluated clinical data from 422 breast cancer patients with brain metastases between 2001 and 2011 from referral centers in Turkey. The study population was divided into four biological subtypes according to their hormone receptor status and HER2 expression. Results: Systemic treatment prolonged median overall survival (OS) after brain metastases in the entire group (14 vs. 3.2 months, p < 0.001). It also prolonged median OS after brain metastases in the triple negative (7.5 vs. 1.6 months, p = 0.010) and luminal A (14.3 vs. 7.1 months, p = 0.003) subgroups. The median OS for untreated patients, chemotherapy and/or hormonal therapy receiving patients, and chemotherapy and/or hormonal therapy plus targeted therapy receivers was 2, 5.8, and 17.7 months, respectively (p < 0.001), in the HER2-overexpressing subgroup. In the luminal B subgroup, it was 3.7, 5.3, and 15.4 months, respectively (p = 0.003). Conclusions: The use of systemic therapy improves OS after brain metastases in all biological subgroups. Targeted therapies also improve OS after brain metastases in HER2-positive patients. The combined use of targeted therapies and lapatinib are superior to single use and trastuzumab, respectively, in these patients. Copyright (C) 2012 S. Karger AG, Base

    Subacute THYROiditis Related to SARS-CoV-2 VAccine and Covid-19 (THYROVAC Study): A Multicenter Nationwide Study.

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    Context The aims of the study are to compare characteristics of subacute thyroiditis (SAT) related to different etiologies, and to identify predictors of recurrence of SAT and incident hypothyroidism. Methods This nationwide, multicenter, retrospective cohort study included 53 endocrinology centers in Turkey. The study participants were divided into either COVID-19-related SAT (Cov-SAT), SARS-CoV-2 vaccine-related SAT (Vac-SAT), or control SAT (Cont-SAT) groups. Results Of the 811 patients, 258 (31.8%) were included in the Vac-SAT group, 98 (12.1%) in the Cov-SAT group, and 455 (56.1%) in the Cont-SAT group. No difference was found between the groups with regard to laboratory and imaging findings. SAT etiology was not an independent predictor of recurrence or hypothyroidism. In the entire cohort, steroid therapy requirement and younger age were statistically significant predictors for SAT recurrence. C-reactive protein measured during SAT onset, female sex, absence of antithyroid peroxidase (TPO) positivity, and absence of steroid therapy were statistically significant predictors of incident (early) hypothyroidism, irrespective of SAT etiology. On the other hand, probable predictors of established hypothyroidism differed from that of incident hypothyroidism. Conclusion Since there is no difference in terms of follow-up parameters and outcomes, COVID-19- and SARS-CoV-2 vaccine-related SAT can be treated and followed up like classic SATs. Recurrence was determined by younger age and steroid therapy requirement. Steroid therapy independently predicts incident hypothyroidism that may sometimes be transient in overall SAT and is also associated with a lower risk of established hypothyroidism

    Mortality analysis of COVID-19 infection in chronic kidney disease, haemodialysis and renal transplant patients compared with patients without kidney disease: A nationwide analysis from Turkey

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    © The Author(s) 2020.Background. Chronic kidney disease (CKD) and immunosuppression, such as in renal transplantation (RT), stand as one of the established potential risk factors for severe coronavirus disease 2019 (COVID-19). Case morbidity and mortality rates for any type of infection have always been much higher in CKD, haemodialysis (HD) and RT patients than in the general population. A large study comparing COVID-19 outcome in moderate to advanced CKD (Stages 3-5), HD and RT patients with a control group of patients is still lacking. Methods. We conducted a multicentre, retrospective, observational study, involving hospitalized adult patients with COVID-19 from 47 centres in Turkey. Patients with CKD Stages 3-5, chronic HD and RT were compared with patients who had COVID-19 but no kidney disease. Demographics, comorbidities, medications, laboratory tests, COVID-19 treatments and outcome [in-hospital mortality and combined in-hospital outcome mortality or admission to the intensive care unit (ICU)] were compared. Results. A total of 1210 patients were included [median age, 61 (quartile 1-quartile 3 48-71) years, female 551 (45.5%)] composed of four groups: Control (n = 450), HD (n = 390), RT (n = 81) and CKD (n = 289). The ICU admission rate was 266/ 1210 (22.0%). A total of 172/1210 (14.2%) patients died. The ICU admission and in-hospital mortality rates in the CKD group [114/289 (39.4%); 95% confidence interval (CI) 33.9-45.2; and 82/289 (28.4%); 95% CI 23.9-34.5)] were significantly higher than the other groups: HD = 99/390 (25.4%; 95% CI 21.3-29.9; P<0.001) and 63/390 (16.2%; 95% CI 13.0-20.4; P<0.001); RT = 17/81 (21.0%; 95% CI 13.2-30.8; P = 0.002) and 9/81 (11.1%; 95% CI 5.7-19.5; P = 0.001); and control = 36/450 (8.0%; 95% CI 5.8-10.8; P<0.001) and 18/450 (4%; 95% CI 2.5-6.2; P<0.001). Adjusted mortality and adjusted combined outcomes in CKD group and HD groups were significantly higher than the control group [hazard ratio (HR) (95% CI) CKD: 2.88 (1.52- 5.44); P = 0.001; 2.44 (1.35-4.40); P = 0.003; HD: 2.32 (1.21- 4.46); P = 0.011; 2.25 (1.23-4.12); P = 0.008), respectively], but these were not significantly different in the RT from in the control group [HR (95% CI) 1.89 (0.76-4.72); P = 0.169; 1.87 (0.81-4.28); P = 0.138, respectively]. Conclusions. Hospitalized COVID-19 patients with CKDs, including Stages 3-5 CKD, HD and RT, have significantly higher mortality than patients without kidney disease. Stages 3-5 CKD patients have an in-hospital mortality rate as much as HD patients, which may be in part because of similar age and comorbidity burden. We were unable to assess if RT patients were or were not at increased risk for in-hospital mortality because of the relatively small sample size of the RT patients in this study

    Epidemiological features of primary glomerular disease in Turkey: a multicenter study by the Turkish Society of Nephrology Glomerular Diseases Working Group

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    Background The largest data on the epidemiology of primary glomerular diseases (PGDs) are obtained from the databases of countries or centers. Here, we present the extended results of the Primary Glomerular Diseases Study of the Turkish Society of Nephrology Glomerular Diseases (TSN-GOLD) Working Group. Methods Data of patients who underwent renal biopsy and received the diagnosis of PGD were recorded in the database prepared for the study. A total of 4399 patients from 47 centers were evaluated between May 2009 and May 2019. The data obtained at the time of kidney biopsy were analyzed. After the exclusion of patients without light microscopy and immunofluorescence microscopy findings, a total of 3875 patients were included in the study. Results The mean age was 41.5 +/- 14.9 years. 1690 patients were female (43.6%) and 2185 (56.3%) were male. Nephrotic syndrome was the most common biopsy indication (51.7%). This was followed by asymptomatic urinary abnormalities (18.3%) and nephritic syndrome (17.8%). The most common PGD was IgA nephropathy (25.7%) followed by membranous nephropathy (25.6%) and focal segmental glomerulosclerosis (21.9%). The mean total number of glomeruli per biopsy was 17 +/- 10. The mean baseline systolic blood pressure was 130 +/- 20 mmHg and diastolic blood pressure was 81 +/- 12 mmHg. The median proteinuria, serum creatinine, estimated GFR, and mean albumin values were 3300 (IQR: 1467-6307) mg/day, 1.0 (IQR: 0.7-1.6) mg/dL, 82.9 (IQR: 47.0-113.0) mL/min and 3.2 +/- 0.9 g/dL, respectively. Conclusions The distribution of PGDs in Turkey has become similar to that in other European countries. IgA nephropathy diagnosed via renal biopsy has become more prevalent compared to membranous nephropathy

    Epidemiological features of primary glomerular disease in Turkey: a multicenter study by the Turkish Society of Nephrology Glomerular Diseases Working Group

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    Background The largest data on the epidemiology of primary glomerular diseases (PGDs) are obtained from the databases of countries or centers. Here, we present the extended results of the Primary Glomerular Diseases Study of the Turkish Society of Nephrology Glomerular Diseases (TSN-GOLD) Working Group. Methods Data of patients who underwent renal biopsy and received the diagnosis of PGD were recorded in the database prepared for the study. A total of 4399 patients from 47 centers were evaluated between May 2009 and May 2019. The data obtained at the time of kidney biopsy were analyzed. After the exclusion of patients without light microscopy and immunofluorescence microscopy findings, a total of 3875 patients were included in the study. Results The mean age was 41.5 +/- 14.9 years. 1690 patients were female (43.6\%) and 2185 (56.3\%) were male. Nephrotic syndrome was the most common biopsy indication (51.7\%). This was followed by asymptomatic urinary abnormalities (18.3\%) and nephritic syndrome (17.8\%). The most common PGD was IgA nephropathy (25.7\%) followed by membranous nephropathy (25.6\%) and focal segmental glomerulosclerosis (21.9\%). The mean total number of glomeruli per biopsy was 17 +/- 10. The mean baseline systolic blood pressure was 130 +/- 20 mmHg and diastolic blood pressure was 81 +/- 12 mmHg. The median proteinuria, serum creatinine, estimated GFR, and mean albumin values were 3300 (IQR: 1467-6307) mg/day, 1.0 (IQR: 0.7-1.6) mg/dL, 82.9 (IQR: 47.0-113.0) mL/min and 3.2 +/- 0.9 g/dL, respectively. Conclusions The distribution of PGDs in Turkey has become similar to that in other European countries. IgA nephropathy diagnosed via renal biopsy has become more prevalent compared to membranous nephropathy
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