Effect of blending conditions on the properties of EPDM/organoclay nanocomposites

17th International Conference on Composite Materials, ICCM-17; Edinburgh; United Kingdom; 27 July 2009 through 31 July 2009The effects of blending conditions on the microstructural and mechanical properties of EPDM / organo modified montmorillonite (OMMT) nanocomposites at various clay loadings were investigated. The effects of the processing conditions were manifested in both the morphology and mechanical properties, which showed significant increase when optimized process conditions are applied.TÜBİTAK-MAG project 106M15

Relationship between MPV and paraoxonase-1 activity, brachial artery diameter and IMT in patients with diabetes mellitus

Aims: Higher mean platelet volume (MPV) in diabetic patients has been considered as an emerging risk factor for diabetes related micro- and macrovascular complications. Human paraoxonase 1/arylesterase (PON1), which has antioxidant and antiatherogenic properties, is documented in high oxidative stress conditions like uncontrolled diabetes. The present study aimed to evaluate the relationship between mean platelet volume (MPV) and paraoxonase-1 (PON-1) activity, brachial artery diameter (BAd) and intima media thickness (BA-IMT), in diabetic patients with regard to obesity and diabetic complications.Methods: Two-hundred and one diabetic patients (mean age: 52.4 ± 13.4 years, 73.6% females) were grouped according to obesity and diabetic complications (microvascular and macrovascular). Data on demographics, anthropometrics, diabetic complications, MPV levels, BAd and BA-IMT, and serum paraoxonase and arylesterase activities were recorded. The correlation of MPV values to paraoxonase and arylesterase activities, BAd and BA-IMT was evaluated.Results: Paraoxonase and arylesterase values were 119.8 ± 37.5 U/L and 149.0 ± 39.9 U/L, respectively, with no significant difference in respect of obesity and macrovascular complications. Significantly lower values for paraoxonase (107.5 ± 30.7 vs. 123.9 ± 38.8 U/L, p = 0.007) and arylesterase (132.1 ± 30.2 vs. 154.7 ± 41.2, U/L, p = 0.001) were noted in patients with microvascular complications. MPV values were 9.10 ± 0.87 fL, with no significant difference across the groups and no significant correlation with other parameters.Conclusion: In conclusion, PON-1 activity is more significantly decreased in diabetic patients with microvascular than macrovascular complications with no effects on MPV values. On the other hand, no relationship was found between thrombogenic activity and PON-1 activity, BAd and BA-IMT regardless of obesity and diabetic complications.Keywords: cardiovascular, diabetes, insulin resistance, obesity, vasculatur

GestaltMatcher Database - A global reference for facial phenotypic variability in rare human diseases

The most important factor that complicates the work of dysmorphologists is the significant phenotypic variability of the human face. Next-Generation Phenotyping (NGP) tools that assist clinicians with recognizing characteristic syndromic patterns are particularly challenged when confronted with patients from populations different from their training data. To that end, we systematically analyzed the impact of genetic ancestry on facial dysmorphism. For that purpose, we established the GestaltMatcher Database (GMDB) as a reference dataset for medical images of patients with rare genetic disorders from around the world. We collected 10,980 frontal facial images - more than a quarter previously unpublished - from 8,346 patients, representing 581 rare disorders. Although the predominant ancestry is still European (67%), data from underrepresented populations have been increased considerably via global collaborations (19% Asian and 7% African). This includes previously unpublished reports for more than 40% of the African patients. The NGP analysis on this diverse dataset revealed characteristic performance differences depending on the composition of training and test sets corresponding to genetic relatedness. For clinical use of NGP, incorporating non-European patients resulted in a profound enhancement of GestaltMatcher performance. The top-5 accuracy rate increased by +11.29%. Importantly, this improvement in delineating the correct disorder from a facial portrait was achieved without decreasing the performance on European patients. By design, GMDB complies with the FAIR principles by rendering the curated medical data findable, accessible, interoperable, and reusable. This means GMDB can also serve as data for training and benchmarking. In summary, our study on facial dysmorphism on a global sample revealed a considerable cross ancestral phenotypic variability confounding NGP that should be counteracted by international efforts for increasing data diversity. GMDB will serve as a vital reference database for clinicians and a transparent training set for advancing NGP technology.</p

Effects of hot melt adhesives on the interfacial properties of overmolded hybrid structures of polyamide-6 on continuous carbon fiber/epoxy composites

This study aims to increase effectivity of the overmolding approach for thermoset/thermoplastics hybrid composites. The samples were prepared by overmolding of polyamide-6 (PA6) onto fully cured continuous carbon fiber-reinforced epoxy composites with the aid of hot melt adhesives. Specifically, the influence of hot melt adhesive application at the interface between the thermoset and thermoplastic parts of hybrid composites was investigated. The experimental scheme highlights the effects of hot melt type and adhesive layer thickness (ALT) on the performance of these hybrid joints. Thermoplastic polyurethane (TPU) based hot melt adhesive performed better adhesion characteristics among others (copolyesters, polyolefin) according to findings from lap shear test and DMA analysis. The fracture surfaces observed with optical microscopy and SEM also confirmed the synergistic effect of these parameters

Overmolded hybrid composites of polyamide-6 on continuous carbon and glass fiber/epoxy composites: 'an assessment of the interface'

In this study, we investigated overmolding of thermoplastics on thermoset composites as an alternative joining method, in order to enable production of hybrid thermoset composites. Specifically, we explored the parameters affecting adhesion between overmolded polyamide-6 (PA6) and continuous glass or epoxy fiber-reinforced composites. Three main factors were studied: type of reinforcing fiber (carbon and glass), moulding temperature during overmolding process (30 °C and 80 °C), and application of peel-ply on composite surface. Overall, peel ply application, higher mould temperature (80 °C) and composite surface with carbon fiber reinforcement resulted in better adhesion. Three point bending, dynamic mechanical analysis (DMA), roughness, and contact angle measurements reveal strong bonding. Scanning electron microscopy (SEM), micro-computed tomography (micro-CT) images and energy-dispersive X-ray spectroscopy (EDS) results support the improvement due to peel-ply application. Findings from thermal analysis confirm the effect of reinforcement material type on crystallinity of overmolded polymer and underline the essential role of contact surface chemistry

Improved Heat Dissipation of NR/SBR-Based Tire Tread Compounds via Hybrid Fillers of Multi-Walled Carbon Nanotube and Carbon Black

The development of thermally conductive rubber nanocomposites for heat management poses a formidable challenge in numerous applications, notably within the realm of tire technology. Notably, rubber materials are characterized by their inherently low thermal conductivity. Consequently, it becomes imperative to incorporate diverse conductive fillers to mitigate the propensity for heat build-up. Multi-walled carbon nanotubes (MWCNTs), as reinforcement agents within the tire tread compounds, have gained considerable attention owing to their extraordinary attributes. The attainment of high-performance rubber nanocomposites hinges significantly on the uniform distribution of MWCNT. This study presents the influence of MWCNTs on the performance of carbon black (CB)-reinforced natural rubber (NR)/styrene butadiene rubber (SBR) tire compounds prepared via high shear melt mixing. Morphological analysis showed a good distribution of MWCNTs in the NR/SBR/CB compound. The vulcanization parameters, such as the maximum and minimum torque, cross-linking density, hardness, abrasion resistance, tensile strength, and Young modulus, exhibited a progressive improvement with the addition of MWCNT. Remarkably, adding MWCNT into CB improved the heat conductivity of the NR/SBR/CB compounds, hence decreasing the heat build-up. A percolation mode was also proposed for the hybrid carbon fillers based on the data obtained

Effect of blending conditions on the properties of EPDM/organoclay nanocomposites

17th International Conference on Composite Materials, ICCM-17; Edinburgh; United Kingdom; 27 July 2009 through 31 July 2009The effects of blending conditions on the microstructural and mechanical properties of EPDM / organo modified montmorillonite (OMMT) nanocomposites at various clay loadings were investigated. The effects of the processing conditions were manifested in both the morphology and mechanical properties, which showed significant increase when optimized process conditions are applied.TÜBİTAK-MAG project 106M15

Bispectral Index Monitoring in Patients Undergoing Open Heart Surgery

Abstract Introduction: To obtain the optimal anesthesia depth is not easy in cardiovascular surgery patients where the haemodynamic reserve is limited, due to reasons such as not being able to give the desired dose of anesthetic agent, or the change in the pharmacokinetics of the agent in the heart-lung machine. This study was planned to assess the contribution of bispectral index (BIS) monitoring in the depth of anesthesia. Methods: The patients were divided into 2 groups, and BIS monitoring was used for each patient. Group 1 (G1 n=35): keeping the BIS monitor screen open, the anesthesia need was set. Group 2 (G2 n=35): BIS monitor was tied to the patient and the monitor screen was closed in such a way that the anaesthesist couldn't see the BIS value. When the recording time came, the data on the monitor was recorded. The need for the anesthetic agent was set according to the parameters such as haemodynamics or follow up of pupils, instead of BIS value, by titrating the anesthetic infusion doses. Results: BIS values were similar in both groups before the induction, BIS values in both groups showed a decrease, showing no significant statistical difference (P>0.05). One patient in each group said that he dreamt, and one patient in G2 said that he had heard a noise and felt that he was taken from one place to another. Conclusion: The management should be done with clinical evaluation, haemodynamics and other monitorization methods and BIS monitoring findings together