Portable wireless electrocorticography system with a fexible microelectrodes array for epilepsy treatment

In this paper, we present a portable wireless electrocorticography (ECoG) system. It uses a high resolution 32-channel fexible ECoG electrodes array to collect electrical signals of brain activities and to stimulate the lesions. Electronic circuits are designed for signal acquisition, processing and transmission using Bluetooth Low Energy 4 (LTE4) for wireless communication with cell phone. In-vivo experiments on a rat show that the fexible ECoG system can accurately record electrical signals of brain activities and transmit them to cell phone with a maximal sampling rate of 30 ksampling/s per channel. It demonstrates that the epilepsy lesions can be detected, located and treated through the ECoG system. The wireless ECoG system has low energy consumption and high brain spatial resolution, thus has great prospects for future application

Patients with IBD have a more cautious attitude towards COVID-19 vaccination

BackgroundTo understand the awareness of COVID-19 vaccine, the willingness to vaccinate and the influencing factors of willingness to vaccinate in inflammatory bowel disease (IBD) patients.MethodsThe online questionnaire was distributed to conduct a survey to analyze and evaluate the willingness, awareness and trust in vaccines of IBD patients. Bivariate analyses and logistic regression models were used to analysis influencing factors.ResultsWe sent the questionnaire to the WeChat group for patient management and 304 patients responded, out of which 16 respondents had to be excluded and 288 respondents were included for the analysis. Among them, 209 patients vaccinated with COVID-19 vaccine. Among the non-vaccinated 79 patients, the main reasons for their concerns were afraid of vaccination aggravating IBD and fear of adverse effects. Our results showed that IBD patients with long disease duration were more willing to receive COVID-19 vaccination (P<0.05). We also observed that a high perception of benefits and cues to action to receive the vaccine were the two most important constructs affecting a definite intention for COVID-19 vaccination (P<0.05).ConclusionsPatients with IBD have a more cautious attitude towards COVID-19 vaccination, which may lead to a higher rate of vaccine hesitancy. Further efforts should be made to protect patients with IBD from COVID-19 infections and achieve adequate vaccination coverage

Flexible thin-film acoustic wave devices with off-axis bending characteristics for multisensing applications

Flexible surface acoustic wave (SAW) devices have recently attracted tremendous attention for their widespread applications in sensing and microfluidics. However, for these applications, the SAW devices often need to be bent into off-axis deformations between the acoustic-wave propagation direction and bending direction. Currently there are few studies on this topic, and the bending mechanisms under off-axis bending deformations have remained unexplored for multi-sensing applications. Herein, we fabricated aluminum nitride (AlN) flexible SAW devices by using high quality AlN films deposited on flexible glass substrates and systematically investigated their complex deformation behaviors. A theoretical model was firstly developed using coupling wave equations and boundary condition method to analyze the device’s characteristics with bending and off-axis deformation under elastic strains. The relationships between frequency shifts of the SAW device with bending strain and off-axis angle were obtained which showed the identical results with those from the theoretical calculations. Finally, we performed proof-of-concept demonstrations of multi-sensing applications by monitoring human wrist movements at various off-axis angles and detecting UV light intensities on a curved surface, thus paving the ways for versatile flexible electronics applications

Preparation and optimization of poly (lactic-co-glycolic acid) rod-shaped particles in nano size range for paclitaxel delivery

Nanoparticle shape has been acknowledged as an important design parameter due to its influence on nanoparticle interaction with biological systems. However, there is lacking of simple and scalable preparation technique for drug loaded non-spherical polymeric nanoparticles for a long time, thus hindering the potential applications. Although our previous research has modified the traditional emulsion solvent evaporation technique by adding guest molecules to prepare non-spherical poly (lactic-co-glycolic acid) (PLGA) particles, it is difficult to obtain nano-sized rods with minor axis less than 200 nm, which may have great potential in cancer therapy. Herein, in present research, the two-step ESE method was used and optimized to prepare poly (lactic-co-glycolic acid) nanorods for paclitaxel delivery. Firstly, the single-factor experiment was used to screen the influence of multi-factors including type of guest molecules, concentration of guest molecules, emulsification method, surfactant concentration, oil volume, poly (lactic-co-glycolic acid) concentration on the size and shape to determine the range of variables; based on the above range, a multi-factor and multi-level orthogonal experiment was designed. The formula is evaluated by the rod fabrication yield and the aspect ratio of major axis to minor axis. The results showed that the yield of nanorods in the optimal formula was 99% and the aspect ratio was 5.35 ± 2.05 with the minor axis of 135.49 ± 72.66 nm, and major axis of 657.77 ± 307.63 nm. In addition, the anti-cancer drug paclitaxel was successfully encapsulated in PLGA nanorods by the same technique. Our results not only enrich the ESE technique for preparing small sized poly (lactic-co-glycolic acid) nanorods, but also envision the potential application of nanorods for targeted cancer therapy with the delivery of paclitaxel

Metasurface spectrometers beyond resolution-sensitivity constraints

Optical spectroscopy plays an essential role across scientific research and industry for non-contact materials analysis1-3, increasingly through in-situ or portable platforms4-6. However, when considering low-light-level applications, conventional spectrometer designs necessitate a compromise between their resolution and sensitivity7,8, especially as device and detector dimensions are scaled down. Here, we report on a miniaturizable spectrometer platform where light throughput onto the detector is instead enhanced as the resolution is increased. This planar, CMOS-compatible platform is based around metasurface encoders designed to exhibit photonic bound states in the continuum9, where operational range can be altered or extended simply through adjusting geometric parameters. This system can enhance photon collection efficiency by up to two orders of magnitude versus conventional designs; we demonstrate this sensitivity advantage through ultra-low-intensity fluorescent and astrophotonic spectroscopy. This work represents a step forward for the practical utility of spectrometers, affording a route to integrated, chip-based devices that maintain high resolution and SNR without requiring prohibitively long integration times

The effect of nitrification inhibitor on N2O, NO and N2 emissions under different soil moisture levels in a permanent grassland soil

[EN] Emissions of gaseous forms of nitrogen from soil, such as nitrous oxide (N2O) and nitric oxide (NO), have shown great impact on global warming and atmospheric chemistry. Although in soil both nitrification and denitrification could cause N2O and NO emissions, most studies demonstrated that denitrification is the dominant process responsible for the increase of atmospheric N2O, while nitrification produces mostly NO. The use of nitrification inhibitors (NIs) has repeatedly been shown to reduce both N2O and NO emissions from agricultural soils; nevertheless, the efficiency of the mitigation effect varies greatly. It is generally assumed that nitrification inhibitors have no direct effect on denitrification. However, the indirect impact, due to the reduced substrate (nitrate) delivery to microsites where denitrification occurs, may have significant effects on denitrification product stoichiometry that may significantly lower soil borne N2O emissions. Soil-water status is considered to have a remarkable effect on the relative fluxes of nitrogen gases. The effect and mechanism of NI on N2O, NO and N-2 emission under different soil water-filled pore space (WFPS) is still not well explored. In the present study, we conducted a soil incubation experiment in an automated continuous-flow incubation system under a He/O-2 atmosphere. Ammonium sulfate was applied with and without NI (DMPP) to a permanent UK grassland soil under three different soil moisture conditions (50, 65, and 80% WFPS). With every treatment, glucose was applied to supply enough available carbon for denitrification. Emissions of CO2, N2O, NO and N-2 were investigated. Additionally, isotopic signatures of soil-emitted N2O were analyzed. Generally, higher WFPS led to higher N2O and NO emissions, while N-2 emissions were only detected at high soil moisture condition (80% WFPS). Different processes were responsible for N2O and NO emission in different phases of the incubation period. The application of DMPP did significantly reduce both N2O and NO emissions at all three soil moisture conditions. Furthermore, DMPP application increased N-2 emissions and decreased the N2O/(N2O + N-2) product ratio at 80% WFPS. (C) 2017 Elsevier Ltd. All rights reserved.Rothamsted Research is sponsored by the BBSRC. This study was in part funded by BBSRC project BB/K001051/1 and supported by the Chinese Scholarship Council (scholarship no. give number 201306350130).Wu, D.; Cárdenas, LM.; Calvet, S.; Brüggemann, N.; Loick, N.; Liu, S.; Bol, R. (2017). The effect of nitrification inhibitor on N2O, NO and N2 emissions under different soil moisture levels in a permanent grassland soil. Soil Biology and Biochemistry. 113:153-160. https://doi.org/10.1016/j.soilbio.2017.06.007S15316011

Three-Dimensional Tetrapodal ZnO Microstructured Network Based Flexible Surface Acoustic Wave Device for Ultraviolet and Respiration Monitoring Applications

Sensitivity of flexible surface acoustic wave (SAW) sensors to ultraviolet (UV) light is enhanced by the application of ZnO micro- and nanostructured networks as sensing layers. In this study, the influence of three-dimensional (3D) tetrapodal ZnO microstructured networks (T-ZnO MNs) spin coated onto Al foil/ZnO piezoelectric film SAW devices on the sensor performance under a stimulus of UV-light irradiation and the influence of relative humidity was investigated. The UV-light sensitivity is increased from −3.03 × 10–6 to −5.25 × 10–6 cm2 mW–1 with the application of 3D T-ZnO MNs. Likewise, the humidity sensitivity is enhanced by a factor of 2.9 at 90% relative humidity, which is explained by the porous structure of T-ZnO MNs. In addition, the measured sensitivity to the UV-light intensity is demonstrated to be significantly modified under bent conditions because the surface of the ZnO piezoelectric film is relatively denser in the case of bending. This study also demonstrates that the sensing performance of the respiratory characteristics is increased by nearly a factor of 1.7 under bent conditions after utilization of the T-ZnO MNs, showing its capability for breath and respiration monitoring applications

Processing Chip for Thin Film Bulk Acoustic Resonator Mass Sensor

Aimed at portable application, a new integrated process chip for thin film bulk acoustic resonator (FBAR) mass sensor is proposed and verified with 0.18 um CMOS processing in this paper. The longitudinal mode FBAR with back-etched structure is fabricated, which has resonant frequency 1.878 GHz and factor 1200. The FBAR oscillator, based on the current-reuse structure, is designed with Modified Butterworth Van Dyke (MBVD) model. The result shows that the FBAR oscillator operates at 1.878 GHz with a phase noise of −107 dBc/Hz and −135 dBc/Hz at 10 KHz and 100 KHz frequency offset, respectively. The whole process chip size with pads is 1300 μm × 950 μm. The FBAR and process chip are bonded together to sense tiny mass. The measurement results show that this chip precision is 1 KHz with the FBAR frequency gap from 25 kHz to 25 MHz