Beton İçindeki Geri Dönüştürülmüş Araç Lastiklerinin Mekanik Özellikleri

Waste tires have been an increasing problem every year due to the increase of vehicle sales. The disposal of waste tires has presented very serious problems to the human community in the world. Currently, some research has been studied on not only waste tire chips (WTC) but also recycled steel tire fibres (RSF) in concrete. Present study is focusing on the usage of WTC and RSF in concrete mixture. The different weight of WTC and RSF is mixed in concrete in order to investigate the effect on mechanical properties. By adding WTC and RSF obtained a satisfactory improvement on cracking control, compressive strength, flexural strength and also tensile strength, Moreover, compressive, flexural and tensile strength was positively affected by the addition of WTC and RSF for some mixtures. More percentage of weight fractions added gives high result in tensile strength. However, the workability of the concrete reinforced with both WTC and RSF was negatively affected.Araç satışlarının artmasıyla birlikte atık lastikler artan bir problem olmaya başladılar. Atık lastiklerin ortadan kaldırılması insular için ciddi problemler ortaya çıkarmaktadır. Günümüzde sadece atık lastik parçalarının (WTC) betonda kullanım değil, atık lastik tellerinin (RSF) de betonda kullanımı araştırılmaktadır. Bu çalışma WTC ve RFS atıklarının beton içinde kullanımını araştırmaktadır. Farklı oranlardaki atıkların betonun mekanik özelliklerine etkisi incelenmektedir. Betona lastik atıklarının katılmasıyla çatlak kontrolünde, basınç dayanımında eğilme ve çekme dayanımlarında iyileşmelerin olduğu görülmüştür. Ayrıca, eğilme çekme dayanımların WTC ve RFS atıklarının katkısıyla pozitif olarak etkilendiği görülmüştür. Atıkların yüzde olarak fazla eklenmesiyle çekme dayanımının artmıştır. Ancak, hem WTC hem de RFS atıklarının ilavesiyle işlenebirlik negatif olarak etkilenmiştir

MECHANICAL CHARACTERIZATION OF RECYCLED TIRES IN CONCRETE

Waste tires have been an increasing problem every year due to the increase of vehicle sales. The disposal of waste tires has presented very serious problems to the human community in the world. Currently, some research has been studied on not only waste tire chips (WTC) but also   recycled steel tire fibres (RSF) in concrete. Recent study is focusing on the usage of WTC and RSF in concrete mixture. The different weight of WTC and RSF is mixed in concrete in order to investigate the effect on mechanical properties. By adding WTC and RSF obtained a satisfactory improvement on cracking control, compressive strength, flexural strength and also tensile strength, Moreover, compressive, flexural and tensile strength was positively affected by the addition of WTC and RSF for some mixtures. More percentage of weight fractions added gives high result in tensile strength. However, the workability of the concrete reinforced with both WTC and RSF was negatively affected

ÇEKME BÖLGESİ LİFLİ BETON OLAN CAM FİBER TAKVİYELİ POLİMER (GFRP) ve ÇELİK DONATILI ETRİYESİZ KİRİŞLERİN EĞİLME ETKİSİ ALTINDAKİ DAVRANIŞI ve HASAR ANALİZİ

Donatı çeliğinde meydana gelen korozyon, yapı elemanlarının önemli problemlerinden biri haline gelmiştir. Bu yüzden son yıllarda, lif takviyeli polimerler (FRP), korozyon dayanımı yüksek olması sebebiyle, çelik donatılara alternatif olarak kullanılmaya başlanmıştır. Ayrıca, FRP donatıların yüksek dayanımı, hafif olması ve kimyasal etkilere karşı dayanımı özellikle endüstriyel alandaki kullanımını arttırmıştır. Bu çalışmada, çekme bölgesinde 5 cm yüksekliğinde polipropilen lif katkılı betonun kullanıldığı çelik ve GFRP donatılı etriyesiz kirişlerin eğilme etkisi altındaki davranışı deneysel olarak incelenmiş ve devamında hasar analizleri yapılmıştır. Bu amaçla geleneksel çelik ve GFRP donatılı etriyesiz kirişler üretilmiş ve üç noktalı eğilme testleri yapılmıştır. Eğilme testleri sonrasında eğilme dayanımları hesaplanarak yük-deplasman grafikleri oluşturulmuş, malzeme davranışındaki farklılıklar incelenmiştir. Deneylerden sonra GFRP donatılarda oluşan hasarlar incelenmiş ve hangi hasar modları olduğu tespit edilmiştir. Çalışmalar sonucunda GFRP donatılı kirişlerin eğilme performanslarının büyük oranda arttığı görülmüştür

ATIK BETONLARIN BETON AGREGASI OLARAK KULLANILABİLİRLİĞİ

Katı atıklarının önemli bir bölümünü oluşturan yapısal inşaat atıklarının geri dönüşümü, çevreye verilen zararları azaltacağı gibi büyük şehirlerde doğal agrega kaynaklarının şehir merkezlerinden çok uzak olmasından dolayı nakliye masraflarının yanında, nakliye sırasında harcanan iş ve zaman kaybını da azaltacaktır. Bu çalışmada, beton basınç mukavemeti 20 MPa olan atık betonlardan elde edilen geri dönüşüm agregalarının fiziksel ve mekanik özellikleri incelenmiş, bu agregalardan farklı karışımlarda beton üretilmiştir. 1. karışımın tamamı geri dönüşüm agregasından oluşmaktadır. 2. karışımın iri agregası geri dönüşüm agregası olup ince agregası kırma taş kumdur. 3. karışımın ise tamamı kırma taş agregadan üretilmiştir. Bütün karışımlar aynı dozajda üretilerek birbirleriyle kıyaslanmıştır. Sonuç olarak; geri dönüşüm agregası kullanılarak üretilen betonlarda geri dönüşüm agregası oranı arttıkça beton basınç mukavemetinde azalma olduğu tespit edilmiştir

The ratio of contrast volume to glomerular filtration rate predicts in-hospital and six-month mortality in patients undergoing primary angioplasty for ST-elevation myocardial infarction

Background: The aim of this study is to determine the impact of ratio of contrast volume to glomerular filtration rate (V/GFR) on development of contrast-induced nephropathy (CIN) and long-term mortality in patients with ST-segment elevation acute myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). Methods: A total of 645 patients with STEMI undergoing primary PCI was prospectively enrolled. CIN was defined as an absolute increase in serum creatinine > 0.5 mg/dL or a relative increase > 25% within 48 h after PCI. The study population was divided into tertiles based on V/GFR. A high V/GFR was defined as a value in the third tertile (> 3.7). Results: Patients in tertile 3 were older, had higher rate of smoking, diabetes mellitus and CIN, lower left ventricular ejection fraction, hemoglobin, and systolic and diastolic blood pressure compared to tertiles 1 and 2 (p < 0.05). V/GFR was found an independent predictor of in-hospital and 6-month mortality. We found 2 separate values of V/GFR for 2 different end points. While the ratio of 3.6 predicted in-hospital mortality with 78% sensitivity and 82% specificity, the ratio of 3.3 predicted 6-month mortality with 71% sensitivity and 76% specificity. Survival rate decreases as V/GFR increases both for in-hospital and during 6-month follow-up. Diabetes mellitus and multivessel disease were other predictors of in-hospital mortality. Conclusions: High V/GFR level is associated with increased in-hospital and long-term mortality in patients with STEMI undergoing primary PCI.

In Vitro Activity of Ceftolozane/tazobactam and Ceftazidime/avibactam Against Carbapenemase-producing Pseudomonas aeruginosa

Conclusion: The results of this study indicate that CZA and C/T may be an alternative treatment for some of the carbapenem-resistant P. aeruginosa infections. Further in vitro and in vivo studies are needed to evaluate the effectiveness of these new treatment options against the increasing threat of MDR P. aeruginosa

Czy galektyna-3 ma związek z nerkowym wydalaniem albumin w cukrzycy typu 2?

  Introduction: The relationship between galectin-3 and diabetes mellitus or renal function has recently been investigated. In this study, we tried to evaluate the association of galectin-3 in urinary albumin excretion levels in type 2 diabetic patients. Material and methods: In a group of 137 type 2 diabetes patients, the mean of the last three urinary microalbumin/creatinine ratios and galectin-3 levels were evaluated. The patient group was divided into three subgroups according to their level of albuminuria calculated with urine microalbumin/creatinine ratio. Results: There was no significant difference between the galectin values of the three subgroups. Significant differences were observed between GFR results of group 1 vs. 3 (p < 0.0001) and group 2 vs. 3 (p = 0.0006), and serum creatinine results of group 1 vs. 3 (p = 0.0003) and group 2 vs. 3 (p < 0.0001). The three subgroups did not reveal any significant difference concerning the age, BMI, duration of DM, FPG, and HbA1c levels. Conclusions: We concluded that serum galectin-3 values are not affected by the levels of urinary albumin excretion in DM patients. We could not find any relation between galectin-3 and the parameters of DM such as FPG, HbA1c, and duration of the disease. (Endokrynol Pol 2016; 67 (6): 580–584)    Wstęp: W ostatnim czasie badano związek między galektyną-3 a cukrzycą i czynnością nerek. Autorzy niniejszego badania podjęli próbę oceny związku galektyny-3 z wydalaniem albumin przez nerki u chorych na cukrzycę typu 2. Materiał i metody: W grupie 137 chorych na cukrzycę typu 2 obliczono średnią ostatnich trzech współczynników mikroalbuminy/kreatynina w moczu oraz pomiarów stężeń galektyny-3. Chorych podzielono na trzy podgrupy w zależności od nasilenia albuminuria określonego na podstawie współczynnika mikroalbuminy/kreatynina w moczu. Wyniki: Nie stwierdzono istotnych różnic pod względem stężeń galektyny między trzema podgrupami. Odnotowano natomiast istotne różnice wartości GFR między grupą 1 i 3 (p < 0,0001) oraz grupą 2 i 3 (p = 0,0006) oraz stężeń kreatyniny między grupą 1 i 3 (p = 0,0003) oraz grupą 2 i 3 (p < 0,0001). Podgrupy nie różniły się istotnie pod względem wieku, BMI, czasu trwania cukrzycy, FPG ani odsetka HbA1c. Wnioski: Autorzy wykazali, że stężenia galektyny-3 w surowicy nie zależą od nasilenia wydalania albumin z moczem u chorych na cukrzycę. Nie stwierdzono zależności między stężeniem galektyny-3 a parametrami charakteryzującymi cukrzycę, takimi jak FPG, HbA1c, czas trwania choroby. (Endokrynol Pol 2016; 67 (6): 580–584)

Epidemiology, anticoagulant treatment and risk of thromboembolism in patients with valvular atrial fibrillation: Results from Atrial Fibrillation in Turkey: Epidemiologic Registry (AFTER)

Background: The aim of this study was to perform a multicenter, prospective investigation regarding the epidemiology, the current effectiveness of therapeutic anticoagulation, and the risk of thromboembolism in patients with valvular atrial fibrillation (AF) based on the records of the Atrial Fibrillation in Turkey: Epidemiologic Registry (AFTER) study. Methods: Patients were selected from a total of 2,242 consecutive admissions that presented with AF diagnosed via electrocardiogram. Those diagnosed with non-valvular AF were excluded from the AFTER study population, which left 497 patients with valvular AF for analysis. Results: The etiology of valvular AF in patients was either attributed to rheumatic mitral valve stenosis (n = 217) or possessing a prosthetic heart valve (n = 280). Out of all the patients with valvular AF, 83.1% were taking warfarin for anticoagulation. Only 36.1% demonstrated a therapeutic international normalized ratio (INR), and among those patients it was found that 19.1% exhibited a labile INR. Multivariate analysis revealed that age was the only independent predictor of thromboembolic events in patients with valvular AF. Conclusions: Many valvular AF patients are not maintained at therapeutic INR levels, which poses a threat to patient health as they age and are at greater risk for thromboembolism

Evaluation of the presence of SARS-COV-2 in the vaginal fluid of reproductive-aged women

Objectives: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is mainly transmitted through respiration and direct contact. The status of the infection in the female genital system is still unknown. The study aimed to evaluate whether SARS-CoV-2 is present in the vaginal fluid of women with COVID-19 infection in reproductive period.Material and methods: Women who were between the ages of 18–50 years and clinically confirmed to have COVID-19 infection at our hospital between 20 April–31 May 2020 were included in the study. Women who were in their menstrual cycle during the study and who had a known cervical intraepithelial lesion and/or cancer, sexually transmitted disease and history and/or symptoms of vaginitis were excluded from the study. In patients in whom no pathology was detected during the examination, a sample was taken from the vaginal fluid for PCR by using Dacron tip swab. Analysis was performed with Genesig Real-Time PCR COVID-19 kit (Primer Design, England).Results: Eighteen women who were in reproductive period and diagnosed with severe COVID-19 pneumonia were included in the study. The mean age of the patients was 38.16 ± 8.54. None of the patients were in their menopause period. The clinical symptoms of these women were similar to those of confirmed severe COVID-19 cases. SARS-CoV-2 was found to be negative in the samples taken from the vaginal fluid in all patients.Conclusions: SARS-CoV-2 virus was not detected in the vaginal fluid of the patients who tested positive for COVID-19 in reproductive period