No abstract

Background and aims: Endoscopic diagnosis of early esophageal squamous cell cancer (ESCC) is complicated and dependent on operators' experience. This study aimed to develop an artificial intelligence (AI) model for automatic diagnosis of early ESCC.Methods: Non-magnifying and magnifying endoscopic images of normal/noncancerous lesions, early ESCC, and advanced esophageal cancer (AEC) were retrospectively obtained from Qilu Hospital of Shandong University. A total of 10,988 images from 5075 cases were chosen for training and validation. Another 2309 images from 1055 cases were collected for testing. One hundred and four real-time videos were also collected to evaluate the diagnostic performance of the AI model. The diagnostic performance of the AI model was compared with endoscopists by magnifying images and the assistant efficiency of the AI model for novices was evaluated. Results:The AI diagnosis for non-magnifying images showed a per-patient accuracy, sensitivity, and specificity of 99.5%, 100%, 99.5% for white light imaging, and 97.0%, 97.2%, 96.4% for optical enhancement/iodine straining images. Regarding diagnosis for magnifying images, the per-patient accuracy, sensitivity, and specificity were 88.1%, 90.9%, and 85.0%. The diagnostic accuracy of the AI model was similar to experts (84.5%, P = 0.205) and superior to novices (68.5%, P = 0.005). The diagnostic performance of novices was significantly improved by AI assistance. When it comes to the diagnosis for real-time videos, the AI model showed acceptable performance as well. Conclusions:The AI model could accurately recognize early ESCC among noncancerous mucosa and AEC. It could be a potential assistant for endoscopists, especially for novices.

Versatile molecularly imprinted polymers (MIPs) have been widely applied to various sample matrices, however, molecular recognition in aqueous media is still difficult. Stimuli-responsive MIPs have received increasing attentions due to their unique feature that the molecular recognition is regulated by specific external stimuli. Herein, water-compatible temperature and magnetic dual-responsive MIPs (WC-TMMIPs) with hydrophilic brushes were prepared via reversible addition-fragmentation chain transfer precipitation polymerization for reversible and selective recognition and extraction of bisphenol A (BPA). Transmission electron microscopy (TEM), Fourier transform infrared spectrometer (FT-IR) and vibrating sample magnetometry (VSM) as characterization methods were used to examine the successful synthesis of polymers, and the resultant WC-TMMIPs showed excellent thermosensitivity and simple rapid magnetic separation. Controlled adsorption and release of BPA by temperature regulation were investigated systematically, and the maximum adsorption and removal efficiency toward BPA in aqueous solutions were attained at 35 °C and 45 °C, respectively, as well as a good recoverability was exhibited with the precision less than 5% through five adsorption-desorption cycles. Phenolic structural analogs were tested and good recognition specificity for BPA was displayed. Accordingly, the WC-TMMIPs were employed as adsorbents for magnetic solid-phase extraction (MSPE) and packed SPE of BPA from seawater samples. Using the two modes followed by HPLC-UV determination, excellent linearity was attained in the range of 0.1-14.5 μM and 1.3-125 nM, with low detection limits of 0.02 μM and 0.18 nM, respectively. Satisfactory recoveries for spiked seawater samples were achieved ranging from 86.3-103.5% and 96.2-104.3% with RSD within 2.12-4.33%. The intelligent WC-TMMIPs combining water-compatibility, molecular recognition, magnetic separation, and temperature regulation proved potentially applicable for selective identification, controlled adsorption/release and high-efficiency enrichment/removal of trace targets in complicated aqueous media.

A simple and sensitive method for the colorimetric detection of mercury ions (Hg 2+ ) has been proposed by using anti-aggregation of gold nanoparticles (AuNPs) based on the co-ordination between thymine and mercury ions. The thymine can bind to the AuNPs through Au-N bonds and induce aggregation of AuNPs. In the presence of Hg 2+ , the thymine was released from the surface of AuNPs via the formation of a thymine-Hg 2+ coordination complex, leading to the dispersion of AuNPs. The detection reagent can be simply prepared by mixing thymine with citrate-capped AuNPs. This method is not only costeffective, but also avoids complicated surface modifications and tedious separation processes.

a b s t r a c tA flexible fluorescent sensing strategy for the recognition and detection of bisphenol A (BPA) has been proposed based on molecularly imprinted polymers (MIPs)-coated gold nanoclusters (AuNCs), by taking advantages of the high selectivity of MIPs and the strong fluorescence property of AuNCs. SiO 2 @AuNCs were initially prepared by making use of the powerful amido bonds between carboxyl-terminated AuNCs and amino-functionalized SiO 2 nanoparticles. Then MIPs-coated AuNCs were formed by anchoring MIP layer on the surface of SiO 2 @AuNCs via a sol-gel process. In the presence of imprinting template BPA, a Meisenheimer complex could be formed between BPA and the primary amino groups on the surface of the AuNCs, and the photoluminescent energy of AuNCs would be transferred to the complex, and thereby result in the fluorescence quenching of AuNCs. The fluorescence-quenching fractions of the sensor presented a satisfactory linearity with BPA concentrations over the range of 0-13.1 M and the detection limit could reach 0.10 M. Distinguished selectivity was also exhibited to BPA over other possibly competing molecules. Moreover, the sensor was successfully applied to determine BPA in seawater, and the average recoveries of BPA at three spiking levels ranged from 91.3 to 96.2% with relative standard deviations below 4.8%. This AuNCs-MIPs based sensor provided great potentials for recognition and determination of phenolic environmental estrogens in complicated samples.

This research is a comparative study of the structural and physical properties of ring, rotor, and friction spun yams and an attempt to explain the differences in their physical properties on the basis of yam structure. Results show that the ring spun yam exhibits the highest fiber migration, followed by rotor spun yam, and friction spun yam with the least. A higher migration factor corresponds with a higher yam breaking tenacity. An analysis of packing density shows that the fibers for the rotor yam are located most densely near the yam center, while the friction yam has the highest density of fibers near the yam surface. The ring spun yam has a moderately uniform distribution of fiber packing density. The experimental results on fiber arrangement near the yam axis show that the friction spun yam has the highest rupture elongation due to the skewed arrangement of fibers around the yam axis. Yam hairiness strongly depends on mean fiber position, with an inward shifting of the packing density leading to low yam hairiness.During the last two decades, a number of new yam forming techniques were developed to increase yarn productivity and impart some new characteristics other than those found in conventional ring spun yarns. Among these modern techniques, open-end rotor and friction spinning systems have drawn much attention from engineers and technologists due to their high productivity, special twist-imparting mechanisms, and yarn characteristics. These technologies differ from ring spinning not only in the design of the spinning units, but also in the physical properties of the yarns, which may be described by the configuration of the fibers.Many researchers have analyzed the structure of ring spun yarns since the early 1950s, focusing on fiber migration. Morton [ 12] found that the intervals of helix profiles decreased as the twist increased. Hearle and Gupta [3] showed that with increased twist, there was a marginal decrease in mean fiber position and magnitude of migration, whereas the migration intensity increased considerably. As for rotor spun yarn, Hearle and his associates [4] concluded that the low strength of rotor spun yarns could be attributed to poor fiber alignment and inferior fiber migration within the yarn body. Lord [9] reaffirmed this view and pointed out that the low tenacity of the rotor spun yam was due to relatively shallower fiber migration, a fairly large number of folded fibers, poor distribution of load over the fibers, high twist multiple, different twist structure, and spinning tension.Luenenschloss and Brockmanns [11] ] used stereo-scanned pictures and cross sections of yams interspersed with tracer fibers to determine the structure of friction spun yams. They concluded that friction spun yams had a stronger migration than ling spun yarns, and the migration moved from the sheath to the core almost without reversal of direction. Rust and Lord [ 16J found that the migration theory for ring spun yams was inadequate for friction spun yams due to the conical disposition of fibers. From ...

No abstract

No abstract