The contact angle of nanofluids as thermophysical property.

Droplet volume and temperature affect contact angle significantly. Phase change heat transfer processes of nanofluids - suspensions containing nanometre-sized particles - can only be modelled properly by understanding these effects. The approach proposed here considers the limiting contact angle of a droplet asymptotically approaching zero-volume as a thermophysical property to characterise nanofluids positioned on a certain substrate under a certain atmosphere. Graphene oxide, alumina, and gold nanoparticles are suspended in deionised water. Within the framework of a round robin test carried out by nine independent European institutes the contact angle of these suspensions on a stainless steel solid substrate is measured with high accuracy. No dependence of nanofluids contact angle of sessile droplets on the measurement device is found. However, the measurements reveal clear differences of the contact angle of nanofluids compared to the pure base fluid. Physically founded correlations of the contact angle in dependency of droplet temperature and volume are obtained from the data. Extrapolating these functions to zero droplet volume delivers the searched limiting contact angle depending only on the temperature. It is for the first time, that this specific parameter, is understood as a characteristic material property of nanofluid droplets placed on a certain substrate under a certain atmosphere. Together with the surface tension it provides the foundation of proper modelling phase change heat transfer processes of nanofluids.

High prevalence of allergy in North Cypriot children.

BACKGROUND: The ISAAC (the International Study of Asthma and Allergies in Childhood) questionnaire has been used to standardize research on the prevalence of asthma in children since 1991. AIM: In this Phase I study, the prevalence of asthma, other allergic diseases and atopy was evaluated in North Cyprus. METHODS: The ISAAC questionnaire was distributed to grades I-V schoolchildren. Data were obtained from parents of 580 schoolchildren aged between 7 and 12 years attending a primary school in Nicosia, the capital of North Cyprus. Of those, a sub-group of 97 (16.7%) randomly selected children were evaluated by skin prick test (SPT) and lung function test (LFT). RESULTS: The prevalence rates of asthma ever, current wheezing and SPT-positivity were 20.8%, 10% and 68%, respectively. The prevalence of atopy was significantly higher in the randomly selected subgroup of 97 (68%) patients subjected to SPT and LFT, and the house dust mite (HDM) was the allergen to which children were most frequently sensitized. CONCLUSIONS: In northern Cyprus, the prevalence rates of asthma, allergic diseases and atopic sensitization in 7-12-year-old children are extremely high. Sensitization to HDM is a risk factor for the development of asthma.

Radiologic diagnosis of a type-III pleuropulmonary blastoma.

Pleuropulmonary blastoma (PPB) is a rare and aggressive dysontogenic neoplasm, occurring in children under the age of 6 years in most cases. CT and MRI findings are well-known, a mixed solid and cystic lesion with variable contrast enhancement and a necrotic centre. We report the radiologic features of type III PPB case.

Bond strength of self-etch adhesives after saliva contamination at different application steps.

This study evaluated and compared the effect of saliva contamination and possible decontamination methods on bond strengths of two self-etching adhesive systems (Clearfil SE Bond [CSE], Optibond Solo Plus SE [OSE]). Flat occlusal dentin surfaces were created on 180 extracted human molar teeth. The two bonding systems and corresponding composite resins (Clearfil AP-X, Kerr Point 4) were bonded to the dentin under six surface conditions (n=15/group): group 1 (control): primer/bonding/composite; group 2: saliva/drying/primer/bonding/composite; group 3: primer/saliva/rinsing/drying/primer/bonding/composite; group 4: primer/saliva/rinsing/drying/bonding/composite; group 5: primer/bonding (cured)/saliva/rinsing/drying/primer/bonding/composite; group 6: primer/bonding (cured)/saliva/removing contaminated layer with a bur/rinsing/drying/primer/bonding/composite. Shear bond strength was tested after specimens were stored in distilled water at 37°C for 24 hours. One-way analysis of variance and Tukey post hoc tests were used for statistical analyses. For CSE, groups 2, 3, and 4 and for OSE, groups 6, 2, and 4 showed significantly lower bond strengths than the control group (p<0.05). CSE groups 5 and 6 and OSE groups 3 and 5 revealed bond strengths similar to the control. When saliva contamination occurred after light polymerization of the bonding agent, repeating the bonding procedure recovered the bonding capacity of both self-etch adhesives. However, saliva contamination before or after primer application negatively affected their bond strength.

A five-year clinical evaluation of direct nanofilled and indirect composite resin restorations in posterior teeth.

AIM: To assess the clinical efficacy of posterior composite resin restorations placed directly and indirectly in posterior teeth after five years. MATERIALS AND METHODS: A total of 108 cavities in 54 patients were restored with three direct composite resins (Filtek SupremeXT [FSXT], Tetric Evo Ceram [TEC], AELITE Aesthetic [AA]) and two indirect composite resins (Estenia [E] and Tescera ATL [TATL]). All restorations were evaluated by two examiners using the United States Public Health Service criteria at baseline and five years after placement. Statistical analysis was completed with Fisher exact and McNemar χ(2) tests. RESULTS: At baseline, 4% (five) of the restored teeth presented postoperative sensitivity; however, only one of them (a member of the E group) required canal treatment and replacement after two years. At the five-year evaluation, all restorations were retained, with Alpha ratings at 100%. Only one tooth (in the TEC group) required replacement after three years due to secondary caries. Color match, surface texture, and marginal integrity were predominantly scored as Alpha after five years for all groups. After that time, marginal discoloration was scored as Alpha in 64% of AE restorations, 70% of TATL restorations, 73% of E restorations, and 87% of FSXT restorations. There were no Charlie scores recorded for any of the restorative systems. CONCLUSIONS: Under controlled clinical conditions, indirect composite resin inlays and direct composite resin restorations exhibited an annual failure rate of 2.5% and 1.6%, respectively, after five years. Therefore, the investigated materials showed acceptable clinical performance, and no significant differences were found among them.

The WHO global alliance against chronic respiratory diseases in Turkey (GARD Turkey).

In order to prevent and control non-communicable diseases (NCDs), the 61st World Health Assembly has endorsed an NCD action plan (WHA resolution 61.14). A package for essential NCDs including chronic respiratory diseases (CRDs) has also been developed. The Global Alliance against Chronic Respiratory Diseases (GARD) is a new but rapidly developing voluntary alliance that is assisting World Health Organization (WHO) in the task of addressing NCDs at country level. The GARD approach was initiated in 2006. GARD Turkey is the first comprehensive programme developed by a government with all stakeholders of the country. This paper provides a summary of indicators of the prevalence and severity of chronic respiratory diseases in Turkey and the formation of GARD Turkey.

Interferon-gamma assays for the diagnosis of tuberculosis infection before using tumour necrosis factor-alpha blockers.

OBJECTIVES: Patients who receive tumour necrosis factor-alpha (TNF-alpha) blockers are mostly immunosuppressed. A study was performed to investigate whether an interferon-gamma (IFN-gamma) assay could represent an alternative approach to the tuberculin skin test (TST) for the diagnosis of latent tuberculosis infection (LTBI) in these patients. DESIGN: We prospectively enrolled 106 individuals into the study in two groups. Group 1 consisted of 38 healthy individuals and Group 2 included 68 patients with chronic inflammatory diseases evaluated for LTBI before the use of TNF-alpha blockers. RESULTS: Of all participants, nine had indeterminate IFN-gamma test results. Agreement between the two tests was poor in both groups (kappa values respectively -0.54 and 0.18). In a total of 97 subjects, 10 (10.3%) were positive by the IFN-gamma test and 49 (50.5%) by TST. CONCLUSION: We found poor agreement between TST and the IFN-gamma test in our study. Our limited preliminary data should be accepted as a basis for designing future studies that will be helpful for physicians to decide whether the IFN-gamma test is more sensitive than the TST test in detecting LTBI before the use of TNF-alpha blockers.

Antioxidant effect of beta-carotene in cystic fibrosis and bronchiectasis: clinical and laboratory parameters of a pilot study.

UNLABELLED: The carotenoids are potent antioxidants with the ability to quench singlet oxygen and other toxic oxygen species. The aim of this pilot study was to investigate the protective effect of beta-carotene on oxidant system in patients with cystic fibrosis (CF) and in patients with bronchiectasis (BE) caused by a reason other than CF. Eighteen children with CF and 15 children with BE followed in the Pediatric Chest Disease Unit of Hacettepe University, and 15 healthy children participated in the study. Compared with the controls, significantly lower plasma levels of beta-carotene were found in the CF group and significantly lower plasma levels of vitamin E in the CF and BE groups. The standardization of carotenoid levels for total cholesterol did not significantly attenuate these differences. In addition, there were significantly higher levels of malondialdehyde (a marker of lipid peroxidation) and tumour necrosis factor-alpha (TNF-alpha) in children with CF and in children with BE than in normal subjects. After 6 mo of beta-carotene supplementation, the plasma levels of beta-carotene and vitamin E increased and the plasma levels of TNF-alpha and malondialdehyde decreased in both groups. CONCLUSION: Potent antioxidants, beta-carotene and vitamin E are deficient in patients with CF and in patients with BE, and they are more susceptible to oxidative damage. These patients may benefit from beta-carotene supplementation.

The Effects of Sublingual Administration of Captopril on Parameters of Exercise Test and Neurohormonal Activation in Patients With Stable Angina Pectoris

A prospective randomized, double-blind, and placebo-controlled study was designed to investigate the effects of sublingual administration of captopril on the parameters of exercise test and neurohormonal activation in patients with stable angina pectoris. A total of 31 patients (28 male, 3 female; mean age 55.4 +/- 9.4 years) took part in the study. Coronary angiography and left ventriculography were performed in all cases and the patients were classified according to the ejection fraction (EF). Following sublingual placebo or 25 mg captopril, plasma levels of renin, angiotensin II, norepinephrine, and serum aldosterone levels were measured at rest and maximal exercise. test was performed. Hormone levels were remeasured immediately after the exercise. The same procedure was repeated the next day using captopril or placebo. Sublingual captopril administration increased the time to angina, the time to 1 mm ST depression, maximal exercise capacity, maximal exercise duration and decreased maximal ST depression, maximal systolic blood pressure, and maximal double product (p < 0.001-0.01). After the maximal exercise test following captopril, the % difference of angiotensin II, aldosterone, and norepinephrine levels was found to be significant lower and the % difference of the renin level was found to be significantly higher than those of placebo (p < 0.001). The effects of sublingual captopril on exercise parameters were additionally assessed in different left ventricular systolic function subgroups. The favorable effects were more prominent in cases with left ventricular systolic dysfunction. There were no adverse effects related to sublingual captopril use. As a result, sublingual administration of captopril improved the parameters of maximal exercise test and suppressed the neurohormonal activation during exercise. We suggest that sublingual captopril may be used effectively before planned daily activities in patients with stable angina pectoris.