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To determine and evaluate the value of shadowing and the twinkling artifact (TA) for the diagnosis of ureteral stones.Related ultrasound images from 117 patients with suspected ureteral stones were consecutively collected with optimized machine settings, confirmed by computed tomography and then retrospectively reviewed by 12 physicians who were classified into 3 groups according to their experience levels: elementary, intermediate, and advanced. The shadowing/TA grades were separately evaluated by all the participating physicians in a blinded manner, and the consistency was verified using Kendall's coefficient of concordance (Kendall's W). Furthermore, the diagnostic performance was compared among the groups stratified by physicians' clinical experience levels and ureteral stone sizes.Using shadowing/TA as indicators for ureteral stones, Kendall's W for the TA evaluation was higher than that for shadowing among all the participating physicians and subgroups (P.05). Furthermore, with no difference in specificity at 100%, the sensitivity of the isolated TA was superior to that of shadowing in groups stratified by the physicians' clinical experience levels and stone sizes, respectively (P.05). However, for the respective comparisons of shadowing and the TA among groups stratified by stone sizes, as ureteral stones became larger, the detection sensitivities all significantly increased (P ≤.001).Among physicians, subjective evaluation of the TA is more consistent and has better diagnostic sensitivity than that of shadowing for the diagnosis of ureteral stones, and the stone size may play an important role in the detection sensitivity of these 2 indicators.

Laminar structure membranes assembled with two-dimensional materials, such as graphene oxide (GO), have attracted wide attention from researchers in waste water treatment. However, it is still a challenge to obtain high-performance membranes by precisely controlling the channel of water permeation. In this work, a series of GO nanosheets and silica (SiO2) nanoparticles were employed to adjust the channel microstructure of GO/SiO2 composite nanofiltration membranes. In general, the use of small-size GO nanosheets in the composite membrane could short the length of the transverse channels between the GO nanosheets and increase the amount of the longitudinal pores among the GO nanosheet edges, thus largely enhancing the water flux of the composite membrane. The addition of small-size SiO2 nanoparticles in the composite membrane could help to form a continuous transverse channel of water permeation, and also greatly raise the water flux. The results showed that the composite membrane prepared with GO (1.2 μm) and SiO2 nanoparticle (25 nm, 30 wt% of the GO mass), had the best performance, the pure water flux was 72.8 L m−2 h−1, and the rejection rate for the dyes was>99.4 %. After being recycled for 8 times, the rejection rate for the dyes was still as high as 97.5%. This work showed that controlling the size of nanosheets and nanoparticles could effectively adjust the channel microstructure of the composite membranes, which was very important for the membrane performance.