[Diagnostic accuracy of liver and spleen stiffness by two dimensional shear wave elastography for portal hypertension in hepatitis B-related cirrhosis].

Objective: To assess the diagnostic accuracy of liver and spleen stiffness measured by two dimensional shear wave elastography (2D-SWE) in hepatitis B-related cirrhosis. Methods: The clinical data of fifty-eight hepatitis B-related cirrhosis patients were collected in Zhongshan Hospital, Fudan University from September 2017 to April 2018. Pearson's correlation analyses were used to assess the relationship between liver/spleen stiffness (L-SWE and S-SWE) and hepatic venous pressure gradient (HVPG), as well as the comparison with serological model. The SWE diagnostic performances of Liver (L-SWE), Spleen (S-SWE) were also evaluated. Results: Of all 58 patients, 47 were found HVPG ≥10 mmHg, diagnosed as clinically significant portal hypertension (CSPH) and severe portal hypertension (SPH), which patients are at increased risk of developing complications. Thirty-four patients were found HVPG≥12 mmHg, diagnosed as SPH, which patients were at increased risk of variceal bleeding. Moderate positive correlation was found between L-SWE and HVPG (r=0.42, P<0.01), and S-SWE were significantly correlated with HVPG (r=0.68, P<0.01), while serological models and HVPG were slightly correlated (r=0.36 and 0.28, all P<0.01). The area under the receiver operating characteristic curves of L-SWE, S-SWE and the combination for CSPH were 0.78, 0.88 and 0.89. When L-SWE was>12.86 kPa or S-SWE was>35.73 kPa, patients were at increased risk of developing complications. The area under the receiver operating characteristic curves for SPH were 0.68, 0.81 and 0.77 and the S-SWE had the highest specificity, so when S-SWE was>41.5 kPa, patients were at increased risk of variceal bleeding. Conclusion: L-SWE and S-SWE are reliable and promising non-invasive parameters to assess CSPH and SPH.

[Computer-aided assessment of liver fibrosis progression in patients with chronic hepatitis B: an exploratory research].

Objective: To establish automatic liver fibrosis classification models by using traditional machine learning and deep learning methods and preliminaryly evaluate the efficiency. Methods: Gray scale ultrasound images and corresponding elastic images of 354 patients, 247 males and 107 females, mean age (54±12) years undergoing partial hepatectomy in Zhongshan Hospital of Fudan University from November 2014 to January 2016 were enrolled in this study. By using traditional machine learning and deep learning methods, an automatic classification model of liver fibrosis stages (S0 to S4) were established through feature extraction and classification of ultrasound image data sets and the accuracy in different classification categories of each model were calculated, by using liver biopsy as the reference standard. Results: Pathological examination showed 73 cases in pathological stage S0, 40 cases in S1, 49 cases in S2, 41 cases in S3, and 151 cases in S4. The traditional machine classification model based on support vector machine (SVM) classifier and sparse representation classifier and the deep learning classification model based on LeNet-5 neural network, their accuracy rates in the two categories (S0/S1/S2 and S3/S4) were 89.8%, 91.8% and 90.7% respectively; the accuracy rates in the three categories (S0/S1 and S2/S3 and S4) were 75.3%, 79.4% and 82.8% respectively; the accuracy in the three categories (S0 and S1/S2/S3 and S4) were 79.3%, 82.7% and 87.2% respectively. Conclusions: Computer-aided assessment of liver fibrosis progression in patients with chronic hepatitis B has a high accuracy, and can achieve a more detailed classification. This method is expected to be applied in the non-invasive evaluation of liver fibrosis in patients with hepatitis B in clinical work in the future.

Towards a transportable aluminium ion quantum logic optical clock.

With the advent of optical clocks featuring fractional frequency uncertainties on the order of 10-17 and below, new applications such as chronometric leveling with few-centimeter height resolution emerge. We are developing a transportable optical clock based on a single trapped aluminum ion, which is interrogated via quantum logic spectroscopy. We employ singly charged calcium as the logic ion for sympathetic cooling, state preparation, and readout. Here, we present a simple and compact physics and laser package for manipulation of 40Ca+. Important features are a segmented multilayer trap with separate loading and probing zones, a compact titanium vacuum chamber, a near-diffraction-limited imaging system with high numerical aperture based on a single biaspheric lens, and an all-in-fiber 40Ca+ repump laser system. We present preliminary estimates of the trap-induced frequency shifts on 27Al+, derived from measurements with a single calcium ion. The micromotion-induced second-order Doppler shift for 27Al+ has been determined to be δνEMMν=-0.4-0.3 +0.4×10-18 and the black-body radiation shift is δνBBR/ν = (-4.0 ± 0.4) × 10-18. Moreover, heating rates of 30 (7) quanta per second at trap frequencies of ωrad,Ca+ ≈ 2π × 2.5 MHz (ωax,Ca+ ≈ 2π × 1.5 MHz) in radial (axial) direction have been measured, enabling interrogation times of a few hundreds of milliseconds.

MicroRNA-490-3p inhibits inflammation and apoptosis induced by spinal cord injury via targeting MK2.

OBJECTIVE: To investigate the regulatory role of microRNA-490-3p in the recovery process of spinal cord injury (SCI) and its underlying mechanism. PATIENTS AND METHODS: Expression levels of microRNA-490-3p and MK2 in peripheral blood of SCI patients and healthy controls were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Glial cells C8-D1A and C8-B4 were induced by H2O2 for constructing in vitro SCI model, followed by detection of microRNA-490-3p and MK2 levels. After glial cells were transfected with microRNA-490-3p mimic or inhibitor, respectively, cell apoptosis and levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were detected. Bioinformatics was used to predict the binding site between microRNA-490-3p and MK2, which was further verified by dual-luciferase reporter gene assay. After construction of MK2 overexpression plasmid, rescue experiments were carried out to confirm the regulatory effect of microRNA-490-3p on MK2 in mediating SCI recovery. RESULTS: MicroRNA-490-3p expression was remarkably lower, whereas MK2 expression was higher in peripheral blood of SCI patients than those of healthy controls. Downregulated microRNA-490-3p and upregulated MK2 were observed in glial cells after H2O2 induction in C8-D1A and C8-B4 cells. Overexpression of microRNA-490-3p remarkably decreased levels of TNF-α and IL-6, as well as alleviated apoptosis in glial cells. Both protein and mRNA levels of MK2 were negatively regulated by microRNA-490-3p. Dual-luciferase reporter gene assay confirmed that MK2 was the target gene of microRNA-490-3p. Finally, rescue experiments verified that the regulatory effects of microRNA-490-3p on alleviating inflammation and apoptosis after SCI were reversed by MK2 overexpression. CONCLUSIONS: MicroRNA-490-3p is lowly expressed in glial cells after SCI. Overexpression of microRNA-490-3p alleviates inflammation and apoptosis via targeting MK2, thereafter promoting SCI recovery.

The carcinogenic effect of solar activity with different intensities on embryos.

The carcinogenic effects of solar activity with different intensities on embryos were studied epidemiologically. The study reveals that receiving a moderate amount of low level cosmic radiation at embryonic stage may reduce cancer occurrence later. This paper analyses and discusses the mechanisms of this hormetic effect.

A modified model of helical resonator with predictable loaded resonant frequency and Q-factor.

High voltage radio frequency (RF) supply is a critical part in an ion trapping system. The RF supply should have high Q-factor and relatively high driving frequency. A frequently used RF supply for an ion trap system is a helical resonator. In certain applications, it is advantageous to have a predictable resonant frequency and Q-factor when the helical resonator is connected to a capacitive load. We develop a model to describe the behavior of a helical resonator with capacitive load. With this model, we can correctly predict the loaded resonant frequency and the loaded Q-factor. To test our prediction, we construct a helical resonator, and measure its resonant frequencies and Q-factors under different capacitive loads. The experimental results agree with our prediction.

A long-term frequency stabilized deep ultraviolet laser for Mg+ ions trapping experiments.

As many precision laser spectroscopy experiments require frequency stabilized lasers, development of long-term stabilized lasers is of great interest. In this work, we report long-term frequency stabilization of a 280 nm deep ultraviolet laser to a high precision wavemeter with digital servo control such that the long-term drift of the laser frequency was greatly reduced. Long-term laser frequency drift was measured with a fiber frequency comb system over 8 h. After locking, the maximum drift rate of the 280 nm laser was lowered from 576 MHz/h to 6.4 MHz/h. With proper environment control of the wavemeter, the maximum drift rate of the 280 nm laser was further lowered to less than 480 kHz/h. The locked laser system was successfully used in a Mg(+) ions trapping experiment, which was also discussed in this work.