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Nickel-plated ultrahigh molecular weight polyethylene (UHMWPE) samples were prepared by an electroless coating method followed by hot pressing. The concentration of Ni in the composites was varied between 3.98 and 10.88 in volume percentage. XRD results revealed that Ni coating was successfully realized on the surface of UHWMPE particles confirmed by SEM–EDS. Ni thickness on the UHMWPE particles has thickness of 2 μm and there was also self-precipitated Ni plates as well as additive Ni particles according to SEM. Hardness values of Ni-coated UHMWPE–Ni composites increased 30% with increasing Ni content. The EMI-SE of the composite increased from 49 up to 70 dB by increasing Ni content for both X and Ku-band with respect to Ni concentration. Our samples, performed very high shielding within X band and also Ku band compared to most of other reports in the open literature, can be suitable for high-performance requirements especially in aerospace applications. [ABSTRACT FROM AUTHOR]

In 1971, Leon Chua theoretically postulated that the memristor is the fourth fundamental circuit element, besides the three well-known circuit elements; namely, resistor, capacitor and inductor. For a long time, because of lack of a simple and practical realization, memristor remained just a theoretical element and rarely appeared in the literature. In 2008, a research team from HP laboratories declared that they had found a physical implementation based on thin films, behaving as a memristor. Memristor can offer new opportunities in circuit design due to its nonlinear behavior and memory. Nevertheless, since a cheap and reliable practical implementation of memristor is yet unavailable on the market, the design of such a realization, which mimics memristor behavior, is vital from the point of view of real-world circuit design. In this paper, a new microcontroller-based memristive chaotic circuit is proposed. Presented design has been implemented using an Ardunio Mega board, which solves numerically the dynamics of the memristor-based chaotic system using Runge-Kutta method. It sends the chaotic signals to the outputs of the circuit, using digital-to-analog converters. Chaotic dynamics and the strange attractors are obtained from the circuit using both, the computer simulations and the lab experiments. Considering both simulation and experimental results, it is shown that the proposed circuit mimics well the dynamics of the memristive chaotic system. [ABSTRACT FROM AUTHOR]

Our environment is full of radio frequency (RF) electromagnetic radiation due to rapid progress of wireless communication technologies, which have many applications, such as base stations of mobile communication networks and wireless internet antennas. In the context of Electromagnetic Compatibility (EMC) discipline, the word shield is used to describe any sort of metal sheet or material capable of reflecting, refracting or absorbing electromagnetic radiation (EMR), which is custom manufactured for the target electronic device casing, in a way to intervene any radiation passing to and from the device. Examining of electromagnetic shielding effectiveness (SE) is an important part of not only ensuring electromagnetic compatibility and of protecting electrical and electronic equipment but also protection of human beings against electromagnetic energy exposure as well. In this study, after a brief introduction and review on electromagnetic shielding, material selection and their applications for an indoor environment protection against electromagnetic radiation are explained. Potential electromagnetic shielding values of fabrics found in the market have been analyzed and compared by considering various criteria and requirements. Experimental results show that around 20 dB shielding effectiveness values can be obtained using test fabrics for a typical indoor environment. [ABSTRACT FROM AUTHOR]

The thermal degradation of zearalenone (ZEA) was investigated using a crust-like model, representing maize bread, which was prepared with naturally contaminated maize flour. Model samples were heated under isothermal conditions at the temperature range of 100–250°C. No reduction was observed at 100°C. Thermal degradation rate constants (k) were calculated as 0.0017, 0.0143 and 0.0216 min−1for 150, 200 and 250°C, respectively. Maize bread baked at 250°C for 70 min was used to test the capability of model kinetic data for the prediction of ZEA reduction. The time–temperature history in the crust and crumb parts was recorded separately. Partial degradation of ZEA at each time interval was calculated by means of the correspondingk-values obtained by using the Arrhenius equation, and the total reduction occurring at the end of the entire baking process was predicted. The reduction in the crumb and crust of bread was also experimentally determined and found to be consistent with the predicted values. It was concluded that the kinetic constants determined by means of the crust-like model could be used to predict the ZEA reduction occurring during baking of maize bread. [ABSTRACT FROM PUBLISHER]

Objective: To demonstrate long-term changes in the prevalence of several types of metabolic derangements in subjects with nonfunctioning adrenal adenomas. Subjects and Methods: 273 subjects with adrenal adenomas, including 231 with nonfunctioning adenoma and 42 with subclinical Cushing's syndrome (sCS), were evaluated with respect to anthropometric and laboratory characteristics and prevalence of type 2 diabetes mellitus (T2DM), hypertension, dyslipidemia, metabolic syndrome (MS), prediabetes and cardiovascular disease (CVD). Median duration was 24 months. Follow-up data of 114 participants with nonfunctioning adrenal adenomas are also presented while those of 117 were missing. Follow-up data regarding changes in anthropometric and laboratory parameters and prevalence rates of metabolic disturbances were obtained from the medical records. Results: The prevalence rates for both patients with nonfunctioning adenoma and sCS were: dyslipidemia: 161 (59%), hypertension: 147 (54%), MS: 128 (47%), prediabetes: 62 (23%), T2DM: 49 (18%), and CVD: 21 (8%). Hypertension and CVD were prevalent in subjects with sCS compared to participants with nonfunctioning adenoma. In follow-up, body mass index (p = 0.005), systolic blood pressure (p < 0.001), waist circumference (p = 0.005), homeostasis model assessment (p = 0.046), high-sensitivity C-reactive protein (p = 0.023), total cholesterol (p < 0.001) and low-density lipoprotein cholesterol (p < 0.001) and prevalence of hypertension (p < 0.001), dyslipidemia (p < 0.001), prediabetes (p < 0.001) and MS (p < 0.01) significantly increased in subjects with nonfunctioning adenoma. Conclusion: The data showed that nonfunctioning adrenal adenomas were associated with the development or deterioration of atherosclerotic risk factors. Therefore, follow-up and management strategies should be developed to decrease atherosclerotic morbidity in those individuals. Copyright © 2012 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

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Objective: Although metformin crosses the placenta, there is no current evidence whether the use of metformin in pregnancy is associated with increased risk of fetal and maternal complications. The aim of this present study is to investigate the attitudes of Turkish physicians in different specialties in terms of metformin use in pregnancy. Materials and Methods: Current opinions were assessed by a questionnaire. Nine hundred forty physicians were invited to join the study; however, completely fulfilled questionnaires could be obtained from a total of 407 physicians (170 family physicians, 139 internists and 98 obstetricians). Results: One hundred fifty-one physicians (37.1%) stated that they recommended metformin use in pregnancy for any of the indications (pregnant women with PCOS, type-2 diabetes or gestational diabetes). Obstetricians were more likely to suggest metformin use in pregnancy rather than other physicians. Metformin use in pregnancy was seldom recommended by internists. The rationales of physicians for the metformin use were: lower risk for abortion, decreased prevalence of maternal and neonatal complications, improvement in insulin resistance, prevention of excess weight gain, better glycemic control in diabetics and decreased insulin need in diabetics taking insulin. Conclusions: Despite limited data on metformin use in pregnancy, significant number of physicians in Turkey supported the metformin use. Obstetricians were the ones most likely to recommend metformin treatment in pregnancy. [ABSTRACT FROM AUTHOR]

Objective: The primary goal of this study is to evaluate predictors of nodular goiter in Graves Disease (GD).Materials and Methods: A total of 202 consecutive patients (mean age: 45; 145 female, 57 male) were enrolled. All patients were treated with antithyroid drugs as initial therapy. TSH, FT3, FT4, TRAb, ATPO, and ATG were measured. Radioactive iodine uptake and thyroid ultrasonography were performed, and thyroid volume and nodule diameter were assessed. Ultrasound-guided fine needle aspiration was performed on thyroid nodules >/= 8mm.Results: Diffuse goiter was detected in 5% of patients. Solitary nodules were detected in 16%, and multi-nodular disease in 33%. Mean nodule diameter was 8.82 mm. Nodular disease was slightly more common in women (p=0.063). Patients with nodular GD were older (p=0.004), had lower levels of FT3 (p=0.016) and TRAB (p=0.002) when compared with subjects with diffuse GD. Age (OR:6.867) was the independent variable predicting nodular GD.Conclusion: Increased prevalence of nodules was associated with advanced age and milder thyrotoxicosis. Apoptosis of thyroid follicular cells due to excess iodine might interfere with nodule formation, and lead to diffuse goiter in severe thyrotoxicosis. Because of increased rate if malignancy in GD, comprehensive evaluation of thyroid nodules of any size is mandatory. [ABSTRACT FROM AUTHOR]

Focuses on the development of computer program based on matrix method to generate extinction cross sections of realistic raindrops. Applicability of interpolation; Establishment of a data bank; Calculation of the corresponding refractive index.

Investigates the problems of plane wave diffraction by an impedance half-plane in cold plasma. Formulation of the boundary-value problem; Reduction of the matrix Wiener-Hopf equation; Accounts on the element of the tensor of dielectric permittivity.

Presents information on the Bethesda System for cervical and vaginal diagnoses that was devised to improve communication between the cytopathologist and referring physician. Categories of squamous intraepithelial lesions; Explanation on the descriptive diagnoses section of the Bethesda System; Information on hormonal evaluation.