Restoration of Intestinal Microbiota After Inulin Supplementation Halted: The Secondary Effect of Supplemented Inulin.

SCOPE: Consumption of inulin could affect the intestinal microbiota composition. Hereby, it is aimed to investigate the intestinal microbial community restoration process when the inulin supplementation is terminated (i.e., the secondary effect). METHODS AND RESULTS: The current study investigates the response and restoration of intestinal microbiota to/after high (Inulin-H) and low (Inulin-L) dosage of inulin supplementation or sequential antibiotics and inulin (Anti-Inulin-L) supplementation, based on analysis of 16S rRNA gene sequences in C57BL/6 mice. The number of significantly changed genera in response to inulin is highest in Anti-Inulin-L (n = 66) group, followed by Inulin-H (n = 51) and Inulin-L (n = 38) group. After inulin supplementation stops, microbiota of all studied groups tend to recover to their original states, with highest percentage of inulin-responding microbes stay significantly different at Anti-Inulin-L (93.94%) group, followed by Inulin-H (74.51%) and Inulin-L (44.12%) groups. Of note, the relative abundance of some non-inulin-responding taxa significantly increases during restoration. CONCLUSION: Sequential antibiotics and inulin supplementation induce greatest changes in the intestinal microbial composition, followed by high and low dosage of inulin. Additionally, the changes induce by supplemented inulin in the intestinal microbial community, provide a chance for some microbes to outcompete the other microbes during the spontaneous restoration.

Dual-FBG bearing fault probe based on a CNN-LSTM-encoder network.

A centimeter-sized bearing fault probe based on dual-fiber Bragg grating vibration sensing is proposed. The probe can provide multi-carrier heterodyne vibration measurements based on swept source optical coherence tomography technology and the synchrosqueezed wavelet transform method to obtain a wider vibration frequency response range and collect more accurate vibration data. For the sequential characteristics of bearing vibration signals, we propose a convolutional neural network with long short-term memory and transformer encoder. This method is proven in bearing fault classification under variable working conditions, and the accuracy rate reaches 99.65%.

Low Frequency Vibration Visual Monitoring System Based on Multi-Modal 3DCNN-ConvLSTM.

Low frequency vibration monitoring has significant implications on environmental safety and engineering practices. Vibration expressed by visual information should contain sufficient spatial information. RGB-D camera could record diverse spatial information of vibration in frame images. Deep learning can adaptively transform frame images into deep abstract features through nonlinear mapping, which is an effective method to improve the intelligence of vibration monitoring. In this paper, a multi-modal low frequency visual vibration monitoring system based on Kinect v2 and 3DCNN-ConvLSTM is proposed. Microsoft Kinect v2 collects RGB and depth video information of vibrating objects in unstable ambient light. The 3DCNN-ConvLSTM architecture can effectively learn the spatial-temporal characteristics of muti-frequency vibration. The short-term spatiotemporal feature of the collected vibration information is learned through 3D convolution networks and the long-term spatiotemporal feature is learned through convolutional LSTM. Multi-modal fusion of RGB and depth mode is used to further improve the monitoring accuracy to 93% in the low frequency vibration range of 0-10 Hz. The results show that the system can monitor low frequency vibration and meet the basic measurement requirements.

Pressure characteristics of a self-Q-switched distributed Bragg reflector fiber laser.

Based on the study of self-Q-switching of a short cavity erbium-doped distributed Bragg reflector (DBR) fiber laser in time domain, the influence of pressure disturbance on the self-Q-switched output is analyzed. In the experiment, the erbium-doped DBR fiber laser (EDFL) was encapsulated with epoxy resin and curing agent to protect and sensitize the fiber. The EDFL sends out self-Q-switched laser pulses when the pump power of the 980 nm laser source is more than 110 mW. The external pressure is exerted on the DBR fiber and increased gradually from 0 g (0 N) to 120 g (1.176 N) in 10 g unit with the pump power fixed at 360 mW, and the following approximately linear changes of self-Q-switched laser pulses outputs are observed by the oscilloscope: the peak voltage of output pulses reduces from 12.59 mV to 1.883 mV; the pulse repetition rate reduces from 125.0 kHz to 66.67 kHz; and the pulse width increases from 0.4083 µs to 1.28 µs.

Wide bandwidth dual-frequency ultrasound measurements based on fiber laser sensing technology.

A dual-frequency ultrasound measurement system based on a distributed Bragg reflector (DBR) fiber laser sensor in a liquid medium was presented. To compare the dual-frequency measurement performance of a DBR fiber laser acoustic sensor with that of a piezoelectric (PZT) ultrasound sensor, two experiments were performed. First, we fixed the driving frequencies of two ultrasound signals at 3 and 5 MHz, and decreased the driving voltage from 15 to 3 V. The outputs of the DBR acoustic sensor show flat-balanced response to dual-frequencies, compared with the PZT acoustic sensor whose response to one of the dual-frequency signals (5 MHz in this paper) has been covered by noise at low acoustic pressure. Then we increased the acoustic pressure by fixing the driving voltage at 20 V, and changed the frequency spacing between the two ultrasound signals. By analyzing the frequency response, sensitivity, signal-to-noise ratio, and noise equivalent pressure of two acoustic sensors under different frequencies, we found that the response of the DBR sensor to wideband dual-frequency is stable, while the response of the PZT sensor deteriorates sharply with increasing frequency spacing. The results demonstrate that the DBR fiber laser sensor performs better for wide bandwidth dual-frequency ultrasound measurements.

Polarimetric heterodyning fiber laser sensor for directional acoustic signal measurement.

A DBR fiber grating laser acoustic sensor based on polarization beat signal modulation analysis has been demonstrated for directional acoustic signal measurement. The acoustic sensor was fabricated in birefringent erbium-doped fiber, and the influences of external-acoustic pressure on fiber grating laser sensor were analyzed, considering the effect of relative orientation of the acoustic wave on the degrees of birefringence modulation. In experiment, the birefringence in sensing fiber was modulated by ultrasonic pressure. Agreement between theoretical and experimental results was obtained for ultrasound wave propagating from different directions (0-360 degrees in 15 degrees intervals) corresponding to a nonlinearly change in beat frequency modulation rates. The results demonstrate that the DBR fiber grating laser acoustic sensor has an orientation recognizable ability, offering a potential for acoustic vector signal detection.