Composites of reactive silica nanoparticles and poly(glycidyl methacrylate) with linear and crosslinked chains by in situ bulk polymerization

Composites of poly(glycidyl methacrylate) (PGMA) and L-lysine-coated silica nanoparticles with varying contents were prepared by in situ bulk polymerization using benzoyl peroxide (BPO) as free radical initiator. Silica nanoparticles covered by L-lysine molecules were synthesized using emulsion method. Dynamic light scattering measurements confirmed that the particles are highly monodisperse with the diameter of 10 nm and free of aggregates in the monomer (glycidyl methacrylate, GMA). Upon polymerization of the homogeneous particle/monomer dispersion, aggregates of individual silica nanoparticles are observed by tapping mode atomic force microscope (AFM). Amine and/or carboxylic acid sites on particle surface covalently react with the oxirane groups of the polymer backbone. The aggregation was substantially suppressed by using a difunctional comonomer divinyl benzene (DVB) in polymerization. A three-dimensional polymer network, P(GMA-DVB), forms throughout the system. This structure leads to significant progress in particle dispersion, therefore in physical properties of the resulting composite. We demonstrated that the composites prepared by crosslinked chains are thermally more stable and mechanically stiffer than those prepared by linear ones.TÜBİTAK TBAG-109T905; TÜBİTAK TBAG-108T446; State Planning Organization (DPT-2003K120690-6

Fabrication of polymer nanofiber-conducting polymer fabric and noncontact motion sensing platform

10th Japanese-Mediterranean Workshop on Applied Electromagnetic Engineering for Magnetic, Superconducting, Multifunctional and Nano Materials, JAPMED’10 2017; Izmir; Turkey; 4 July 2017 through 8 July 2017Conductive polymer-electrospun polymer nanofiber network was combined to host iron oxide nanoparticles providing micrometer thick sensing interface. The sensor has fabricated as freestanding fabric exhibiting 10 to 100 KOhm base resistivity upon bias applied. The moving object has been sensed through the electrostatic interactions between fibers and object. The sensing range has been found to be 1-5 cm above the surface of fabric. By the controlled combination of conductive polymers electrospun polymer nanofibers effective device miniaturization has been provided without loss of performance. The noncontact motion sensor platform has unique flexibility and light weight holding a potential for wearable sensor technology

Integration of triboluminescent EuD4TEA crystals to transparent polymers: Impact sensor application

Lanthanide-based organometallic materials are well-known candidate triboluminescent (TL) materials that can show bright emission when a mechanical force is applied. These materials are usually in the form of crystalline powders, and it is often useful to integrate these samples into a polymer matrix in order to achieve processability, enabling coating from a solution/molten state or fabrication as a complex-shaped matrix. In this work, micrometer-sized europium tetrakis (dibenzoylmethide) triethylammonium (EuD4TEA) crystals were synthesized and integrated with various transparent polymers (PMMA, PS, PVDF, and PU) using two approaches: (i) blending and (ii) surface impregnation. In the former method, the crystalline particles were molecularly dissolved; therefore, a TL response cannot be achieved. More than 10 wt % TL crystals in the composite is needed to obtain TL signals. However, TL signal was achieved at 2.5 wt % when a composite was prepared by the latter approach. TL intensity shows exponential decay with consecutive mechanical action. The TL emission of PU-based surface impregnated composite expires with long-lived emission, and maximum TL response with respect to applied force was measured between 2.45 and 42.0 N.Scientific and Technological Research Council of Turkey (TUBITAK KBAG-114Z292

Investigation of oxygen permeation through composites of PMMA and surface-modified ZnO nanoparticles

Oxygen permeabilities of nanocomposite films consisting of poly(methyl methacrylate) (PMMA) and different amounts of spherical zinc oxide (ZnO) nanoparticles were determined to investigate the barrier effect of this material with respect to particle content. A method was applied which is based on quenching of an excited phosphorescent dye by oxygen. Possible effects of the nanoparticles on the response of the dye molecules were investigated and were ruled out

Retrospectively Analysis of Clinical/Pathological and Prognostic Features of Subtypes of Breast Cancer

DergiPark: 379007tmsjAims: Breast cancer is the most common type of cancer among all women across the world, with an incidence of 25.2%. Of all the cancer cases, breast cancer comes second in line after lung cancer. By 6.4% it marks fifth place as the reason for cancer-related-deaths. Therefore new studies on breast cancer are required. We aimed to retrospectively analyze clinical, pathological and prognostic features of cases that were divided into four subgroups based on their hormone receptor and HER-2 conditions. Method: Records of GATA-Oncology Clinic patients who have been diagnosed with breast cancer within years of 2008-2014, were inspected retrospectively. Cases were divided into four subgroups based on their hormone receptor and HER-2 conditions. Missing records were primarily gathered by electronic recording system, also still-missing-information about the patients were provided via phone calls. Collected data has been evaluated with SPSS 15,0. Results: While demographics such as family history and menopausal state were not different among 4 subgroups, triple negative patients tended to have a lower body-mass index and mean age (p=009, p=0.041, respectively). Only 12 patients had advanced disease at diagnosis. A total of 168 patients received chemotherapy. Progression occurred in 41 patients (21.9%) from early phase breast cancer cases that were taken to adjuvant chemotherapy program. Family history had a significant association with recurrence in breast cancer patients (p=0.026). Menopausal state, lymphovascular invasion, lymph node state and stage were not associated with progression. Independent prognostic factors were not obtained with multivariate analysis for disease-free survival. Advanced stage breast cancer patients had a higher tendency to metastasis. Triple negative patients had more drug resistance towards systemic treatment than other subgroups (p lt;0.001). It has been found that full response to anthracycline + taxane regime was less in triple negative patients. Conclusion: In conclusion, there were some differences within our subgroups. Patients of these subgroups should be followed up and treated with different strategies. All subgroups, especially triple negative group, were in need of new effective therapy strategies

Metal kaplı nano fiberler

Mevcut buluş, nano-­fiberlerin metal kaplanması için bir yönteme, bu yöntemle elde edilen metal kaplı nano-­fiberlere ve bu metal kaplı nano-­fiberlerin kullanımına ilişkindir.Sabancı Üniversites

Anti-neuronal antibodies associated with headache with neurological deficits and cerebrospinal fluid lymphocytosis

5OCT333-335

Role of free radicals in peptic ulcer and gastritis

Background/aims: It has been suggested that the free radicals are closely related with peptic ulcer disease and gastritis. Although many studies have been undertaken to clarify the role of oxygen-derived free radicals, most of them were carried out in animal models. The aim of this study was to assess the reactive oxygen species activity and the damage in Helicobacter pyloriinfected gastric mucosa in humans. Methods: In a total group of 42, there were fifteen cases of peptic ulcer, 14 cases of gastritis and 12 control subjects. Measurement of gastric mucosal malondialdehyde concentrations, which is the end - product of lipid peroxidation, was used to assess oxidative damage to membranes in patients with peptic ulcer and gastritis. Mucosal reduced glutathione glutathione concentrations were also measured in order to study whether reactive oxygen species generation affects levels of the antioxidant peptide, malondialdehyde and glutathione content was then measured in biopsies taken from the gastric antrum. Results: Tissue levels of glutathione were significantly (p <0.001) and malondialdehyde was higher (p<0.001) in patients with peptic ulcer compared to controls. In patients with gastritis, glutathione was also lower (p<0.001) and malondialdehyde higher (p<0.01). Conclusions: Depletion of gastric mucosal glutathione in cases with H.pylori positive peptic ulcer and gastritis may be caused by accumulation of free radicals that can initiate membrane damage by lipid peroxidation