Nonisocyanate based polyurethane/silica nanocomposites and their coating performance

A series of silica nano-particles with different size were prepared by sol–gel technique, then surface modification by using cyclic carbonate functional organoalkoxysilane (CPS) was performed. Various amounts of carbonated silica particles directly added into carbonated soybean oil (CSBO) and carbonated polypropylene glycol (CPPG) resin mixture to prepare polyurethane–silica nanocomposite coating compositions by nonisocyanate route using an aliphatic diamine as a curing agent. Cupping, gloss, impact, and taber abrasion tests were performed on aluminum panels coated with those nano-composite formulations and tensile tests, thermogravimetric and SEM analyses were conducted on the free films prepared from the same coating formulations. An increase in abrasion resistance of CSBO-CPPG resin combination with the addition of silica was observed. In addition, the maximum weight loss of CSBO-CPPG resin combination was shifted to higher temperatures with incorporation of silica nano-particles The positive effect of modified silica particles on thermal stability of CSBO-CPPG system could be explained in such a way that PPG chains are able to disperse particles in the medium throughout the interactions between ether linkages and silanol groups

Turkish Paediatric Dentists’ Knowledge, Experiences and Attitudes Regarding Child Physical Abuse

Objectives Numerous studies have shown that the education of health professionals is essential to effectively respond to child abuse. The present study aimed to evaluate Turkish paediatric dentists\u27 knowledge, experiences and attitudes regarding child physical abuse. Materials and methods An electronic questionnaire was e‐mailed to 518 paediatric dentists. Participants’ knowledge of diagnostic indicators of child physical abuse, and their past experiences, attitudes and self‐assessment of educational needs were evaluated. Results The response rate was 40.9% (n = 212). Participants who completed their undergraduate education before 1997 received significantly less education on child physical abuse than participants who completed their education more recently (P \u3c 0.001). Although statistically insignificant, participants who completed their doctorate/specialty training after 2012 received increased education on child physical abuse (P = 0.06). Of the participants, 43.9% suspected physical abuse; however, only 12.7% reported it. ‘I did not know where and how to report’ was the most common reason for not reporting physical abuse. The rate of suspicion was higher among dentists from state hospitals or oral health centres (P \u3c 0.05). Of the participants, 70.3% did not know about the legal sanctions for delay in or not reporting suspected cases. Only 15.6% assessed themselves as competent to diagnose and report physical abuse. Almost all of them acknowledged their need for more education on this topic. Conclusion Turkish paediatric dentists’ educational needs for diagnosing and reporting of child physical abuse cases should be met

Diizosiyanatların polimerleşme aktivitelerinin hesapsal yöntemlerle incelenmesi

Poliüretan polimerler çok amaçlı reçineler, yüzey kaplama malzemeleri, boyar maddeler vb. gibi geniş kullanım alanına sahiptir. Diizosiyanat bileşikleri, poliüretan sentezinde monomer olarak kullanılmaktadır. Ancak, bu polimerlerin üretimleri sırasında kanserojen ve toksik özellik gösteren izosiyanat gruplarından bir kısmı tepkimeye girmeden açıkta kalmakta ve insan sağlığı için tehdit oluşturmaktadır. Bu durum, hemen her alanda yaygın olarak kullanılan poliüretan malzemelerinin üretiminde sanayinin karşısına ciddi bir sorun olarak çıkmaktadır. Bu nedenle izosiyanat monomerlerinin reaktiviteleri ile ilgili bilgiler, insana ve çevreye zararsız polimerlerin tasarlanması için önemlidir. Bu çalışmanın birinci amacı, ticari monomer olarak kullanılan diizosiyanatların reaktifliklerini teorik yöntemlerle incelemektir. İkinci amacı ise, yapısında yanmaya karşı dayanıklılık sağlayacak fosfor grubu içeren, bis(4-izosiyanatofenil)fenil fosfinoksit monomerinin hesapsal yöntemlerle elektronik yapı özelliklerinin ve polimerleşme reaktifliğinin incelenmesidir. Elde edilen sonuçlar, fosfor grubu içeren monomerin, ticari olarak kullanılan mevcut diizosiyanatlardan daha reaktif olduğunu göstermiştir. Bu durum, yapısındaki izosiyanat gruplarının tepkimeye girmeden açıkta kalma olasılığını azaltacağından dolayı insan sağlığı ve çevre açısından daha olumlu bir özelliktir. Elde edilen teorik bulgular umut vaad etmekte ve ileride yapılabilecek deneysel çalışmalar için de yön gösterici niteliktedir

Early Clinical Features of Pseudoexfoliation Syndrome in Anterior Segment and Gonioscopy Examination

Objectives: To determine the early signs of pseudoexfoliation (PEX) in fellow eyes of cases with unilateral PEX. Materials and Methods: Fellow eyes of 34 cases with unilateral PEX were evaluated by slit-lamp and gonioscopy. Findings associated with PEX were recorded. Results: Mean age was 67.8±8.1 years (range 55-86 years). Twenty-five patients (73.5%) had pigmentation in the inferior angle and 23 patients (67.6%) had Sampaolesi’s line located on the inferior angle in fellow eyes. The other most common findings were loss of peripupillary ruff in 10 patients (29.4%) and pigment dispersion following pupil dilation in 14 patients (41.1%). Conclusion: Pigmentation in the inferior angle and Sampaolesi’s line on the inferior angle seem to be the most common early findings associated with PEX. Special attention should be paid to these findings in cases with ocular hypertension for proper management

Molecular weight controlled sulfonated Poly(Arylene Ether)s and sulfonated Poly(Ether Ether ketone) polymer blends for fuel cell applications

We synthesized molecular weight-controlled and fluorine-containing PAEs (MWCPAEs) using decafluorobiphenyl (DFBP), 2-bis (4-hydroxyphenyl) propane (Bis A), and 2,2-Bis (4-hydroxyphenyl) hexafluoropropane (Bis AF). Later, commercially available PEEK and the MWCPAEs were sulfonated (SPEEK and SMWCPAE) and blended to fabricate blend membranes (BMs). All BMs have been prepared by solution casting method in 5 wt%-20 wt% concentrations using N,N-dimethylacetamide. The effects of chemical structures, sulfonation levels, MW and compositions on the membrane properties are discussed. We obtained miscible and mechanically compatible BMs. The highest proton conductivity (238.9 mS/cm) was determined for SPEEK70/S-DFBP-Bis-A based blend membrane (Mw: 48.355, 5wt. %). All chemical, mechanical, thermal, and hydrolytic properties of the BMs are comparable with, or better than, that of Nafion. We suggest that designing polymeric structures with desired MWs and sulfonation levels may enable enhanced properties and can help to design materials with on demand properties

Misdiagnosed chest pain: Spontaneous esophageal rupture

Chest pain is one of themost common complaints expressed by patients presenting to the emergency department, and any initial evaluation should always consider life-threatening causes. Esophageal rupture is a serious condition with a highmortality rate. If diagnosed, successful therapy depends on the size of the rupture and the time elapsed between rupture and diagnosis.We report on a 41-year-old woman who presented to the emergency department complaining of left-sided chest pain for two hours

AN E-GOVERNMENT PROJECT MANAGEMENT APPROACH WITH E-TRANSFORMATION PERSPECTIVE

AN E-GOVERNMENT PROJECT MANAGEMENT APPROACH WITH E-TRANSFORMATION PERSPECTIV