A Real-Time Method for Improving Stability of Monolithic Quartz Crystal Microbalance Operating under Harsh Environmental Conditions

Monolithic quartz crystal microbalance (MQCM) has recently emerged as a very promising technology suitable for biosensing applications. These devices consist of an array of miniaturized QCM sensors integrated within the same quartz substrate capable of detecting multiple target analytes simultaneously. Their relevant benefits include high throughput, low cost per sensor unit, low sample/reagent consumption and fast sensing response. Despite the great potential of MQCM, unwanted environmental factors (e.g., temperature, humidity, vibrations, or pressure) and perturbations intrinsic to the sensor setup (e.g., mechanical stress exerted by the measurement cell or electronic noise of the characterization system) can affect sensor stability, masking the signal of interest and degrading the limit of detection (LoD). Here, we present a method based on the discrete wavelet transform (DWT) to improve the stability of the resonance frequency and dissipation signals in real time. The method takes advantage of the similarity among the noise patterns of the resonators integrated in an MQCM device to mitigate disturbing factors that impact on sensor response. Performance of the method is validated by studying the adsorption of proteins (neutravidin and biotinylated albumin) under external controlled factors (temperature and pressure/flow rate) that simulate unwanted disturbances.

Photobiomodulation Effects of Single Near-Infrared (825 nm), Green (525 nm) and Combination of Wavelengths on Adipose-Derived Mesenchymal Stem Cell Physiology

Photobiomodulation (PBM) has been used as a bio stimulatory tool for adipose-derived mesenchymal stem cells (ADMSCs). The goal of this in vitro research was to examine the effects of combined and/or single applications of near infra-red (NIR) and green PBM using 5 J/cm2 on ADMSCs. The results indicated that the viability of ADMSCs are not affected by single or combined wavelengths of 525 and 825 nm at 5 J/cm2. However, PBM significantly stimulated cell metabolism seen by an increase in proliferation, it also upregulated intracellular ROS and MMP using 825 nm and 525 nm wavelengths. The combined wavelength irradiation mimicked results found for 825 nm during ATP measurement, cell concentration and migration rate, however significant MMP stimulation and increased ROS production was achieved. In conclusion, results indicate that the combination wavelengths of 525 and 825 nm can be used in the expansion and differentiation of ADMSCs for regenerative purposes.

LncRNA WT1-AS up-regulates p53 to inhibit the proliferation of cervical squamous carcinoma cells

Background It has been reported that the development of cervical squamous cell carcinoma (CSCC) requires the involvement of a large number of lncRNAs. In a recent study lncRNA, WT1-AS was been characterized as a tumor-suppressive lncRNA in gastric cancer. In our study we aim to explore the involvement of WT1-AS in CSCC. Methods Seventy-six CSCC patients (20 to 63 years, 40.1 ± 6.1 year) from the 233 CSCC patients who were admitted by the Affiliated Tumour Hospital of Xinjiang Medical University between august 2010 and January 2014. RT-qPCR, cell proliferation rate measurement, cell transfection, and western blot were carried out to analyze the samples. Results We found that HPV infection failed to affect WT1-AS expression in CSCC tissues, while WT1-AS was down-regulated in CSCC tissues compared with non-cancer tissues. P53 was also down-regulated in CSCC tissues and positively correlated with WT1-AS. Analysis of the survival of CSCC patients revealed that low levels of WT1-AS were accompanied by poor survival. Significantly up-regulated p53 was observed after WT1-AS over-expression in CSCC cells, while p53 over-expression failed to affect WT1-AS. P53 and WT1-AS over-expression resulted in the inhibited proliferation of CSCC cells. Conclusion Therefore, WT1-AS is down-regulated in CSCC and it may inhibit CSCC cell proliferation at least partially by up-regulating p53.

Analysis of impedance measurements of a suspension of microcapsules using a variable length impedance measurement cell

Electrical impedance measurements of a suspension have to take into account the double layer impedance that results from a very thin charged layer formed at the electrode-electrolyte interface. A dedicated measuring cell that enables variation of the distance between the electrodes was developed to investigate the electrical properties of suspensions using two-electrode impedance measurements. By varying the distance between the electrodes it is possible to separate the double layer and the suspension impedance from the measured data. Electrical ‘lumped’ models have been developed from measured and extracted impedances. The error of non-inclusion of the double layer impedance has been analyzed. The error depends on the frequency of the measurement as well as the distance between the electrodes.

Online Measurement of Internal Parameters in a Quasi-CW Diode-Pumped Nd:YAG Laser

We present a simple and practical online measurement method to estimate internal parameters (small-signal gain coefficient, internal optical losses, the saturation parameter, and transmittance of the coupling output mirror) in an neodymium doped yttrium aluminum garnet Nd:YAG laser system. A measurement cell, placed in the optical cavity of a laser, consists of a polarizer and a rotatable polarization analyzer. Internal parameters are measured conveniently by introducing variable polarization reflective loss. Online measurements of the internal parameters in a quasi-continuous-wave (CW) diode-pumped Nd:YAG laser are performed and the measured results, which are discussed and analyzed, indicate good measurement accuracy. Experiments to investigate validity are conducted and further verify the applicability of the measurement method. A measurement cell with a small volume that is easy to access has potential to be used in the online measurement, optimized design, and maintenance of a laser.

An Efficient Multi-Path Multitarget Tracking Algorithm for Over-The-Horizon Radar

In target tracking environments using over-the-horizon radar (OTHR), one target may generate multiple detections through different signal propagation paths. Trackers need to jointly handle the uncertainties stemming from both measurement origin and measurement path. Traditional multitarget tracking algorithms suffer from high computational loads in such environments since they need to enumerate all possible joint measurement-to-track assignments considering the measurements paths unless they employ some approximations regarding the measurements and their corresponding paths. In this paper, we propose a novel algorithm, named multi-path linear multitarget integrated probabilistic data association (MP-LM-IPDA), to efficiently track multitarget in multiple detection environments. Instead of generating all possible joint assignments, MP-LM-IPDA calculates the modulated clutter measurement density for each measurement cell of each track. The modulated clutter measurement density considers the possibility that the measurement cells originate from the clutter as well as from other potential targets. By incorporating the modulated clutter measurement density, the single target tracking structure can be applied for multitarget tracking, which significantly reduces the computational load. The simulation results demonstrate the effectiveness and efficiency of the proposed algorithm.

Термоэдс тонких пленок Bi-=SUB=-1-x-=/SUB=-Sb-=SUB=-x-=/SUB=- (0≤ x≤0.15) на подложках из слюды и полиимида в температурном интервале 77-300 K

This report presents the results of the study of thermoelectricpower of the thin block films of Bi1−xSbx (0 ≤ x ≤ 0.15) with the thickness of 100−1000 nm on the mica and polyimide substrates in the temperature range 77−300 K. The applied technique for measuring thermoelectric power allows to prevent the additional film deformation due to the difference in the thermal expansion of the sample in question and measurement cell. The structure, temperature dependences of the thermopower and the resistivity of thin films were analyzed, and the power factor was estimated. A difference was found in the nature of the temperature dependences of the thermopower and the specific resistance of films on mica and polyimide substrates. This difference is explained by the change of the band structure parameters under the influence of film deformation due to the difference in the thermal expansion of the film and substrate.

Method of Measurement Representativeness Assessment for Spatial Conductometric Sensors as Applied to Investigation of Hydrodynamics in Single Phase Flows

The well-known method of spatial conductometry is widely used for hydrodynamical investigations in the frame of validation benchmarks. The aim of the work was to develop the method of representativeness substantiation for use of the conductometric sensors in single-phase applications.The paper presents aspects of wire-mesh sensors (WMS) applications in non-uniform conductivity fields. The equivalent electrical circuits for the measurement cell and WMS are proposed and investigated. The methods of translation from measured conductance to conductivity of the water are discussed. Decomposition of the uncertainty sources and their propagation through measurements are investigated.To obtain the «cross-talk» effect of the measurements the fi model of WMS fl domain was created. The results of calculations showed the dependence of the measurement results on the conductivity contrast in the cells as well as on the size of the contrast domain. The proposed method of the measurement uncertainty estimate was applied to the real WMS and it’s measurement system. The obtained results are topical for validation tests with the use of tracer methods and WMS.