Atık Olivin Mineralinin Asfalt Betonunda Filler Olarak Kullanımı

Bu çalışmada ferrokrom tesislerinde kromit cevherinin zenginleştirilmesi sürecinde ortaya çıkan atık olivin malzemesinin esnek üstyapılarda filler olarak kullanılabilirliği araştırılmıştır. İlk aşamada geleneksel kırmataş kalker agregası tozu kullanılarak elde edilen gradasyonda sabit filler oranı %4.7 olarak alınmış ve bitüm oranı %3,5, %4,0, %4,5, %5,0, %5,5 alınarak optimum bitüm yüzdesi elde edilmiştir. İkinci aşamada, ilk aşamada bulunan optimum bitüm yüzdesi ile geleneksel kırmataş kalker agregası tozuna %0, %25, %50, %75 ve %100 oranlarında olivin ikame edilerek oluşturulan numunelere; stabilite, akma, pratik özgül ağırlık, boşluk yüzdesi, asfalt dolu boşluk yüzdesi ve agregalar arası boşluk yüzdesi deneyi yapılmıştır. Elde edilen sonuçlara göre geleneksel kırmataş kalker agregası filler malzemesiyle ikame edilen olivin yüzdelerine göre asfalt betonunun mühendislik özelliklerinin değişimi karşılaştırılmıştır. Sonuç olarak olivinin sıcak karışım asfalt betonlarda filler malzeme olarak kullanılabileceği görülmüştür

Improvement of Geotechnical Properties of Clayey Soil Using Biopolymer and Ferrochromium Slag Additives

The geotechnical properties of clay soil and its mixtures with different proportions (0.75%, 0.85%, 1%, and 1.15%) of Agar Gum biopolymer and Ferrochromium Slag (0.25%, 0.50%, 0.75%, and 1%), having various curing times and freeze-thaw cycles, were studied through a series of soil mechanical tests to investigate possibilities to improve its undesired/problematic plasticity, compaction, and shear strength characteristics. The results revealed that treatment with an optimal ratio of 1% Agar Gum and 1% Ferrochromium Slag alone, as well as together with, improved the geotechnical properties of the clay soil considerably. Both the unconfined and shear strength properties, along with the cohesion and internal friction angle, increased as much as 47 to 173%, depending on the curing time. The higher the curing time, the higher the shear strength, cohesion, and internal friction angle are up to 21 days. Deteriorating the soil structure and/or fabric, freeze-thaw cycles, however, seem to have an adverse effect on the strength. The higher the freeze-thaw cycle, the lower the shear strength, cohesion, and internal friction angle. Also, some improvements in the plasticity and compaction properties were determined, and environmental concerns regarding Ferrochromium Slag usage have been addressed

Mortality Risk Factors among Critically Ill Children with Acute COVID-19 in PICUs: A Multicenter Study from Turkish Pediatric Critical COVID-19 and MIS-C Study Group

© 2022 Lippincott Williams and Wilkins. All rights reserved.Background: During the coronavirus disease 2019 (COVID-19) pandemic, the world has a large number of reported COVID-19 cases and deaths. Information on characteristics and mortality rate of pediatric intensive care unit (PICU) cases with COVID-19 remains limited. This study aims to identify the risk factors for mortality related to COVID-19 in children admitted to PICU. Methods: A retrospective multicenter cohort study was conducted between March 2020 and April 2021 at 44 PICUs in Turkey. Children who were 1 month-18-year of age with confirmed COVID-19 admitted to PICU were included in the study. Children with multisystem inflammatory syndrome and asymptomatic for COVID-19 were excluded. Results: Of 335 patients with COVID-19, the median age was 6.8 years (IQR: 1.2-14) and 180 (53.7 %) were male, 215 (64.2 %) had at least one comorbidity. Age and gender were not related to mortality. Among 335 patients, 166 (49.5%) received mechanical ventilation, 17 (5.1%) received renal replacement therapy and 44 (13.1 %) died. Children with medical complexity, congenital heart disease, immunosuppression and malignancy had significantly higher mortality. On multivariable logistic regression analysis, organ failure index [odds ratio (OR): 2.1, 95 confidence interval (CI): 1.55-2.85], and having congenital heart disease (OR: 2.65, 95 CI: 1.03-6.80), were associated with mortality. Conclusions: This study presents detailed data on clinical characteristics and outcomes of patients with COVID-19 admitted to PICU in the first pandemic year in Turkey. Our study shows that having congenital heart disease is associated with mortality. In addition, the high organ failure score in follow-up predict mortality

Lung cancer from suspicion to treatment: An indicator of healthcare access in Turkey

Background: Lung cancer is the leading cause of cancer-related deaths worldwide. Before beginning lung cancer treatment, it is necessary to complete procedures such as suspecting lung cancer, obtaining a pathologic diagnosis, and staging. This study aimed to investigate the processes from suspicion of lung cancer to diagnosis, staging, and treatment initiation. Methods: The study was designed as a multicenter and cross-sectional study. Patients with lung cancer from various health institutions located in all geographic regions of Turkey were included in the study. The sociodemographic and clinical characteristics of the patients, the characteristics of the health institutions and geographic regions, and other variables of the lung cancer process were recorded. The time from suspicion of lung cancer to pathologic diagnosis, radiologic staging, and treatment initiation, as well as influencing factors, were investigated. Results: The study included 1410 patients from 29 different medical centers. The mean time from the initial suspicion of lung cancer to the pathologic diagnosis was 48.0 ± 52.6 days, 39.0 ± 52.7 days for radiologic staging, and 74.9 ± 65.5 days for treatment initiation. The residential areas with the most suspected lung cancer cases were highly developed socioeconomic zones. Primary healthcare services accounted for only 0.4% of patients with suspected lung cancer. The time to pathologic diagnosis was longer in the Marmara region, and the wait time for staging and treatment initiation was longer in Eastern and Southeastern Anatolia. Patients who presented to chest disease referral hospitals with peripheral lesions, those with early-stage disease, and those who were diagnosed surgically had significantly longer wait times. Conclusion: The time between pathologic diagnosis, staging, and treatment initiation in lung cancer was longer than expected. Increasing the role of primary healthcare services and distributing socioeconomic resources more equally will contribute to shortening the time to diagnosis and improve treatment processes for lung cancer

Efficacy of subsequent treatments in patients with hormone-positive advanced breast cancer who had disease progression under CDK 4/6 inhibitor therapy.

Background There is no standard treatment recommended at category 1 level in international guidelines for subsequent therapy after cyclin-dependent kinase 4/6 inhibitor (CDK4/6) based therapy. We aimed to evaluate which subsequent treatment oncologists prefer in patients with disease progression under CDKi. In addition, we aimed to show the effectiveness of systemic treatments after CDKi and whether there is a survival difference between hormonal treatments (monotherapy vs. mTOR-based). Methods A total of 609 patients from 53 centers were included in the study. Progression-free-survivals (PFS) of subsequent treatments (chemotherapy (CT, n:434) or endocrine therapy (ET, n:175)) after CDKi were calculated. Patients were evaluated in three groups as those who received CDKi in first-line (group A, n:202), second-line (group B, n: 153) and >= 3rd-line (group C, n: 254). PFS was compared according to the use of ET and CT. In addition, ET was compared as monotherapy versus everolimus-based combination therapy. Results The median duration of CDKi in the ET arms of Group A, B, and C was 17.0, 11.0, and 8.5 months in respectively; it was 9.0, 7.0, and 5.0 months in the CT arm. Median PFS after CDKi was 9.5 (5.0-14.0) months in the ET arm of group A, and 5.3 (3.9-6.8) months in the CT arm (p = 0.073). It was 6.7 (5.8-7.7) months in the ET arm of group B, and 5.7 (4.6-6.7) months in the CT arm (p = 0.311). It was 5.3 (2.5-8.0) months in the ET arm of group C and 4.0 (3.5-4.6) months in the CT arm (p = 0.434). Patients who received ET after CDKi were compared as those who received everolimus-based combination therapy versus those who received monotherapy ET: the median PFS in group A, B, and C was 11.0 vs. 5.9 (p = 0.047), 6.7 vs. 5.0 (p = 0.164), 6.7 vs. 3.9 (p = 0.763) months. Conclusion Physicians preferred CT rather than ET in patients with early progression under CDKi. It has been shown that subsequent ET after CDKi can be as effective as CT. It was also observed that better PFS could be achieved with the subsequent everolimus-based treatments after first-line CDKi compared to monotherapy ET