4 research outputs found
Investigating the knot performance of silk, polyamide, polyester, and polypropylene sutures
The knot performance of four different nonabsorbable sutures-silk, polyester, polyamide, and polypropylene-is investigated by using square knots with two and three throws. All sutures are USP 2/0 in size. An instrument that can be mounted on the Instron tensile tester measures the knot performance of the sutures. The results are given as stress-elongation graphic, knot slippage, and knot break values. The effects of the number of throws and the structure of the sutures on knot performance are studied. For the knot performance tests, the effect of the physical structure (braided or monofilament) is clearly seen. For monofilament polyamide and polypropylene sutures, the knot with two throws unties before it breaks. For silk and polyester braided sutures, which have reasonably good two-throw square knot strength, the added throw does not remarkably increase strength and at the same time places more suture material in the tissue, which increases the risk of infection. Three-throw knot results reveal that the suture material plays an important role in knot strength
Mass size distribution and source identification of particulate matter metal components at four urban sites and a background site of Istanbul
In this study, the size distribution characteristics and metal contents of particulate matter (PM) have been determined. In this scope, PM sampling has been done at five stations in Istanbul. PM filter samples were collected for eight different sizes using the Anderson cascade impactor. PM filters were decomposed and analyzed for 20 metals. The highest median concentration for Fe, Ca, K, and Mg, known as soil metals, were observed as follows: Fe and Ca were observed at Goztepe station (1.20 and 8.28 mu g/m(3)), K was observed at Kilyos station (0.33 mu g/m(3)), and Mg was observed at Avcilar station (0.37 mu g/m(3)). The highest median concentrations for Zn, Cu, Pb, Ni, Cr, V, As, Se, Co, and Cd, known as anthropogenic metals, were observed at Avcilar, Goztepe, and Besiktas stations. Although the lowest metal concentrations was determined at Kilyos stations that was selected as the urban background. The enrichment factors (EFs) of most metals in the fine PM is higher than those in the coarse mode. According to the factor analyses, the most important emission source was observed to be industrial facilities at Avcilar; traffic at Besiktas; traffic and domestic heating at Goztepe; and domestic heating, sea salt aerosols, and ship traffic (in the Bosphorus Channel of Istanbul) at Rasathane
Incidence, risk factors and severity of retinopathy of prematurity in Turkey (TR-ROP study): a prospective, multicentre study in 69 neonatal intensive care units
Background To evaluate the prevalence, risk factors and treatment of retinopathy of prematurity (ROP) in Turkey and to establish screening criteria for this condition.
Methods A prospective cohort study (TR-ROP) was performed between 1 April 2016 and 30 April 2017 in 69 neonatal intensive care units (NICUs). Infants with a birth weight (BW)=1500 g or gestational age (GA) 1500 g or GA> 32 weeks with an unstable clinical course were included in the study. Predictors for the development of ROP were determined by logistic regression analyses.
Results The TR-ROP study included 6115 infants: 4964 (81%) with a GA 32 weeks. Overall, 27% had any stage of ROP and 6.7% had severe ROP. A lower BW, smaller GA, total days on oxygen, late-onset sepsis, frequency of red blood cell transfusions and relative weight gain were identified as independent risk factors for severe ROP in infants with a BW=1500 g. Of all infants, 414 needed treatment and 395 (95.4%) of the treated infants had a BW <= 1500 g. Sixty-six (16%) of the treated infants did not fulfil the Early Treatment for Retinopathy of Prematurity requirements for treatment.
Conclusions Screening of infants with a GA <= 34 weeks or a BW<1700 g appears to be appropriate in Turkey. Monitoring standards of neonatal care and conducting quality improvement projects across the country are recommended to improve neonatal outcomes in Turkish NICUs