Water-stable plasma-polymerized N,N-dimethylacrylamide coatings to control cellular adhesion

The plasma polymerization of amide-based precursors is a nearly unexplored research area, which is in contrast with the abundance of reports focusing on amide based surface modification using wet chemistry. Therefore, this study aims to profoundly investigate the near-atmospheric pressure plasma polymerization of N,N-dimethylacrylamide (DMAM) to obtain stable coatings. In contrast to the unstable coatings obtained at lower discharge powers, the stable coatings that were obtained at higher powers showed a lower hydrophilicity as assessed by water contact angle (WCA). This decrease in hydrophilicity with increasing plasma power was found to be related to a reduced preservation of the monomer structure, as observed by Fourier transform infrared (FTIR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and XPS C-60 depth profiling, a rarely used but effective combination of techniques. Furthermore, the chemical composition of the coating was found to be in good agreement with the plasma active species observed by optical emission spectroscopy. Additionally, XPS C-60 depth profiling indicated a difference between the top layer and bulk of the plasma polymer due to spontaneous oxidation and/or postplasma coating deposition. Finally, the stable coatings were also found to have cell-interactive behavior toward MC3T3 as studied by in vitro live/dead fluorescence imaging and (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) (MTS) assays. With the latter technique, a cell viability of up to 89% as compared with tissue culture plates after 1 day of cell culture was observed, indicating the potential of these coatings for tissue engineering purposes

TOTAL IONIZING DOSE EFFECTS AND RADIATION TESTING

Total ionizing dose (TID) effects and radiation tests of complex multifunctional Very-large-scale integration (VLSI) integrated circuits (ICs) rise up some particularities as compared to conventional "simple" ICs. The main difficulty is to organize informative and quick functional test dirctly under irradiation. Functional tests approach specified for complex multifunctional VLSI devices is presented and the basic radiation test procedure is discussed in application to some typical examples. 

Thermal Raman study of Li4Ti5O12 and discussion about the number of its characteristic bands

Lithium battery industry is booming, and this fast growth should be supported by developing industry friendly tools to control the quality of positive and negative electrode materials. Raman spectroscopy was shown to be a cost effective and sensitive instrument to study defects and heterogeneities in lithium titanate, popular negative electrode material for high power applications, but there are still some points to be clarified. This work presents a detailed thermal Raman study for lithium titanate and discusses the difference of the number of predicted and experimentally observed Raman-active bands. The low temperature study and the analysis of thermal shifts of bands positions during heating let us to conclude about advantages of the proposed approach with surplus bands and recommend using shifts of major band to estimate the sample heating

ALGORITHM OF MULTIHARMONIC DISTURBANCE COMPENSATION IN LINEAR SYSTEMS WITH ARBITRARY DELAY: INTERNAL MODEL APPROACH

Subject of Research. The problem of multiharmonic disturbance compensation for the class of linear time-invariant plants with known parameters and delay is considered. Method. The disturbance is presented as unmeasurable output of linear autonomous model (exosystem) with known order and unknown parameters. The problem is resolved with the use of parametrized representation of disturbance designed by means of exosystem state observer and predictor of this state that finally enables applying certainty equivalence principle. In order to remove undesirable influence of delay a modified adaptation algorithm is created. The algorithm is based on augmentation of the plant state vector and generates advanced adjustable parameters for control. As distinct from widespread approaches, the proposed algorithm does not require identification of disturbance parameters and gives the possibility to remove such restrictions as adaptation gain margin and time delay margin. Main Results. Simulation results obtained in MATLAB/Simulink environment are presented to demonstrate the performance of proposed approach. Results illustrate the boundness of all signals in the closed-loop system and complete compensation of harmonic signal. It is shown that the proposed idea makes it possible to increase the adaptation gain for different delays without system stability loss. Practical Relevance. The algorithm of adaptive compensation is recommended for the use in such problems as: the problem of control for active vibration protection devices wherein several dominating harmonics can be taken from the spectrum of vibration signal; the problems of control of robotics systems with periodical behavior; the problems of ship roll compensation; the problems of space plants control in the presence of uncontrollable rotation

METHOD FOR INTEGRATED CIRCUITS TOTAL IONIZING DOSE HARDNESS TESTING BASED ON COMBINED GAMMA- AND X-RAY IRRADIATION FACILITIES

A method is proposed to test microelectronic parts total ionizing dose hardness based on a rationally balanced combination of gamma- and X-ray irradiation facilities. The scope of this method is identified, and a step-by-step algorithm of combined testing is provided, along with a test example of the method application

The Design Technique for Power Management Unit of the Tag IC for Radio Frequency Identification of Critical Infrastructure Objects

The ultra-high frequency (UHF) tag IC’s main part of the power management unit (PMU) design technique is presented. The technique is a step-by-step algorithm for designing a PMU and consists of five interrelated stages. At the first stage, the requirements for the parameters of the PMU (output voltage, output DC power, efficiency, output capacitor capacity) and the Q-factor of the tag analog front-end are determinates. At the second stage, the design of an electrical circuit of a voltage multiplier (VM) is carried out. VM is required to convert the voltage of the input radio frequency (RF) signal into an DC voltage. During the third stage, the design of the electrical circuit of the DC voltage limiter is carried out, which is necessary to reduce the output voltage of VM to a safe level. The result of stage 4 is an electrical circuit of surge protection designed to provide the required level of immunity of the tag IC to the effects of electrostatic discharge and a high-power RF signal. As part of the final stage, the evaluation and alignment with the required Q-factor value of the tag IC analog front-end is carried out. The proposed technique can be used for the development of domestic UHF tag ICs (ISO 18000-6C, GJB 7377.1, etc.) based on CMOS technological processes, including ICs designed for radio frequency identification of critical infrastructure objects. Using the presented technique, the design of a PMU with an estimated efficiency value of 70%, an estimated Q-factor of the analog front-end of less than 15 at an RF input signal power of -12.7 dBm was performed

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Chromosome errors, or aneuploidy, affect an exceptionally high number of human conceptions, causing pregnancy loss and congenital disorders. Here, we have followed chromosome segregation in human oocytes from females aged 9 to 43 years and report that aneuploidy follows a U-curve. Specific segregation error types show different age dependencies, providing a quantitative explanation for the U-curve. Whole-chromosome nondisjunction events are preferentially associated with increased aneuploidy in young girls, whereas centromeric and more extensive cohesion loss limit fertility as women age. Our findings suggest that chromosomal errors originating in oocytes determine the curve of natural fertility in humans. [Abstract copyright: Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.