N-doped carbon dots coupled with molecularly imprinted polymers as a fluorescent sensor for ultrasensitive detection of genistein in soya products.

Rapid detection of genistein in soya products has remained difficult. Current methods necessitate sample handling and use of costly instruments. Here, using a simple one-pot reverse microemulsion method, a sensor based on N-doped carbon dots conjugated molecularly imprinted polymers (N-CDs@MIPs) was synthesized to analyze genistein. N-doped carbon dots were used as fluorescent component, genistein as the template molecule, and molecularly imprinted polymers as the selective sorbent in this fluorescence sensor. The sensor was then examined and optical studies demonstrated that N-CDs@MIPs not only had strong fluorescence emission and outstanding optical stability, but also had good sensitivity (detection limit 35.7 nM) and selectivity to genistein. Furthermore, the N-CDs@MIPs materials were used to analyze genistein in soya products, and the findings (which ranged from 99.77% to 106.11%) show that the N-CDs@MIPs has high potential for quickly detecting the amount of genistein in complicated food samples.

Factors associated with adherence to screening before diagnosis of hepatocellular carcinoma related to chronic hepatitis B / 预防医学

Objective@#To investigate the factors associated with the patient's adherence to screening in the five years before the diagnosis of hepatocellular carcinoma (HCC) related to chronic hepatitis B ( CHB ), so as to provide reference for improving the screening rate.@*Methods@#From June 2016 to April 2018, the patients with newly diagnosed HCC and a history of CHB for more than five years in Southwest Hospital in Chongqing were interviewed. The information about socio-demographic characteristics, health status, medical care and HCC screening in the past five years were collected. A multivariate logistic regression model was used to analyze the factors associated with adherence to screening. @*Results@#Among 420 participants, 140 ( 33.33% ) adhered to HCC screening, 124 ( 29.53% ) had irregular/incomplete screening, while 156 ( 37.14% ) never had screening. The proportion of early-stage HCC at diagnosis was significantly higher in patients who adhered to screening ( 77.14% ) than that in patients who had irregular/incomplete screening (35.48%) or no screening ( 12.82% ) and the differences were statistically significant ( P<0.05 ). The multivariate analysis demonstrated that five factors were significantly associated with patient's adherence to screening, including education level of high school and above ( OR=2.346, 95%CI: 1.370-4.017), family history of HCC ( OR=2.795, 95%CI: 1.457-5.362 ), history of chronic diseases ( OR=3.860, 95%CI: 2.052-7.262), acceptance of antiviral therapy ( OR=17.816, 95%CI: 9.702-32.716 ) and specialized clinic visits ( OR=8.332, 95%CI: 1.588-43.710 ).@*Conclusions@#Adherence to screening is conducive to the early detection of HCC, but the screening rate is low in the patients with CHB. Education level, history of HCC, health status and medical status are significantly related to screening adherence.

Spherical shock-wave propagation in three-dimensional granular packings.

We investigate numerically the spherical shock-wave propagation in an open dense granular packing perturbed by the sudden expansion of a spherical intruder in the interior of the pack, focusing on the correlation between geometrical fabrics and propagating properties. The measurements of the temporal and spatial variations in a variety of propagating properties define a consistent serrated wave substructure with characteristic length on the orders of particle diameters. Further inspection of particle packing reveals a well-defined particle layering that persists several particle diameters away from the intruder, although its dominant effects are only within one to two diameters. This interface-induced layering not only exactly coincides with the serrated wave profile, but also highlights the competition between two energy transmission mechanisms involving distinct transport speeds. The alternating dominances between these two mechanisms contribute to the nonlinear wave propagation on the particle scale. Moreover, the proliferation of intricate three-dimensional contact force networks suggests the anisotropic stress transmission, which is found to also arise from the localized packing structure in the vicinity of the intruder.